question 36
In Exercises 35, 36, 37, 38, 39, 40, 41 and 42, find functions f and g such that h = gof. (Note: The answer is not unique.) 37. h (x) = V2 – 1

Answers

Answer 1

To find functions f and g such that h = gof, we need to determine how the composition of these functions can produce [tex]h(x) = √(2 - 1).[/tex]

Let's choose [tex]f(x) = √x and g(x) = 2 - x.[/tex] Now we can check if gof = h.

First, compute gof:

[tex]gof(x) = g(f(x)) = g(√x) = 2 - √x.[/tex]

Now compare gof with h:

[tex]gof(x) = 2 - √x = h(x) = √(2 - 1).[/tex]

We can see that gof matches h, so the functions [tex]f(x) = √x and g(x) = 2 - x[/tex]satisfy the condition h = gof.

learn more about:-  functions here

https://brainly.com/question/31062578

#SPJ11


Related Questions

(i) Find the gradient at the point (1, 2) on the curve given by: I+ry + y2 = 12 – 22 - y2 (ii) Find the equation of the tangent line to the curve going through the point (1,2)

Answers

The gradient at the point (1, 2) on the curve is -1. The equation of the tangent line to the curve at the point (1, 2) is y = -x + 3.

To find the gradient at a specific point on the curve, we need to differentiate the equation with respect to y and substitute the coordinates of the point into the derivative.

The given equation is: I + ry + y^2 = 12 – 2^2 - y^2

Differentiating both sides with respect to y, we get:

r + 2y = 0

Substituting the x-coordinate of the point (1, 2), we have:

r + 2(2) = 0

r + 4 = 0

r = -4

Therefore, the gradient at the point (1, 2) on the curve is -1.

(ii) To find the equation of the tangent line to the curve at the point (1, 2), we can use the point-slope form of a line. The equation of a line with gradient m passing through the point (x₁, y₁) is given by y - y₁ = m(x - x₁).

Using the point (1, 2) and the gradient -1 we found earlier, we can substitute these values into the equation to find the tangent line:

y - 2 = -1(x - 1)

y - 2 = -x + 1

y = -x + 3

Therefore, the equation of the tangent line to the curve at the point (1, 2) is y = -x + 3.

Learn more about tangent line here:

https://brainly.com/question/23416900

#SPJ11

b. Suppose that you find out the intercept of the regression b, is 32.705, then how much is the slope of the regression b ? c. Then you wonder whether there is a significant relationship between the r"

Answers

b. The intercept of the regression, denoted as b₀, is the value of the dependent variable when the independent variable is zero.

In this case, the intercept is given as 32.705.

c. To determine the slope of the regression, denoted as b₁, we need additional information. The slope represents the change in the dependent variable for a one-unit increase in the independent variable.

If you have the full regression equation in the form of y = b₀ + b₁x, where y is the dependent variable and x is the independent variable, you can directly identify the slope (b₁) from the equation.

However, if you only have the intercept (b₀) and do not have the full equation, it is not possible to determine the slope (b₁) without additional information.

To assess the significance of the relationship between the variables, you would typically look at the p-value associated with the slope coefficient in the regression analysis. The p-value helps determine if the relationship is statistical significant. A small p-value (usually less than 0.05) indicates that the relationship is unlikely to be due to random chance and suggests a significant relationship.

Without the availability of the p-value or the full regression equation, it is not possible to determine the significance of the relationship between the variables.

Learn more about statistical here:

https://brainly.com/question/31538429

#SPJ11

Solve the equation. 3 dy dx Sar Buy = 4x° (5+y?) ?) An implicit solution in the form F(x,y) = C is = C, where C is an arbitrary constant. (Type an expression using x and y as the variables.)

Answers

The implicit solution is:
F(x,y) = e^(-4/3(x²+C)) - y - 5 = 0, where C is an arbitrary constant.

To solve the equation 3dy/dx + 4x°(5+y?) = 0, we can first isolate the dy/dx term by dividing both sides by 3:
dy/dx = -4x°(5+y?)/3

Next, we can separate variables by multiplying both sides by dx and dividing both sides by -4x°(5+y?):
-3/(4x°) dy/(5+y?) = dx

Integrating both sides with respect to their respective variables, we get:
-3/4 ln|5+y?| = x² + C
where C is an arbitrary constant.

Solving for y, we can exponentiate both sides:
|5+y?| = e^(-4/3(x²+C))
y = ±(e^(-4/3(x²+C))) - 5

Thus, the the implicit solution in the form F(x,y) = C is:
F(x,y) = e^(-4/3(x²+C)) - y - 5 = 0, where C is an arbitrary constant.

To learn more about implicit solution visit : https://brainly.com/question/20709669

#SPJ11

Find the volume of the solid generated by revolving the region bounded by y=4√sinx,y=0,x1=π4 and x2=2π3about the x-axis.

Answers

The volume of the solid generated by revolving the region bounded by y = 4√sin(x), y = 0, x = π/4, and x = 2π/3 about the x-axis is (22π)/3 - 8.

To find the volume, we can use the method of cylindrical shells. We integrate the circumference of each shell multiplied by its height over the interval [π/4, 2π/3], and then sum up all the volumes of the shells.

The height of each shell is given by the function y = 4√sin(x), and the circumference is given by 2πx. Therefore, the volume of each shell is 2πx(4√sin(x))dx.

Integrating this expression over the interval [π/4, 2π/3], we get the volume as (22π)/3 - 8.

Hence, the volume of the solid generated is (22π)/3 - 8.

Learn more about cylindrical shells here:

https://brainly.com/question/31259146

#SPJ11

please help me with question 10
Muha QUESTION 10 The function/66) 232-37-72 - 95 is indicated in the diagram blow. (-5:), Che the streets and D and Eure the minst points of AC-5:0) AN 10.1 Calelate the coordinates of und 99 10.2 Cal

Answers

Given the function f(x) = x² - 6x - 95, we are to calculate the coordinates of the y-intercept and the x-intercepts of the graph of the function in question 10.

We are also to find the interval in which the function is increasing or decreasing.10.1.

Calculation of the y-intercept We recall that the y-intercept is the point at which the graph of the function intersects the y-axis.

At the y-intercept, x = 0.

Therefore, substituting x = 0 in the equation of the function,

we have y = f(0) = (0)² - 6(0) - 95 = -95

Therefore, the coordinates of the y-intercept are (0, -95).10.2.

Calculation of the x-intercepts

We recall that the x-intercepts are the points at which the graph of the function intersects the x-axis.

At the x-intercept, y = 0.

Therefore, substituting y = 0 in the equation of the function,

we have:0 = x² - 6x - 95Applying the quadratic formula,

we have:x = (-b ± √(b² - 4ac)) / 2aWhere a = 1, b = -6, and c = -95.

Substituting the values of a, b, and c, we have:

x = (6 ± √(6² - 4(1)(-95))) / 2(1)x

= (6 ± √(36 + 380)) / 2x = (6 ± √416) / 2x

= (6 ± 8√26) / 2x

= 3 ± 4√26

Therefore, the coordinates of the x-intercepts are (3 + 4√26, 0) and (3 - 4√26, 0).

The interval of Increase or Decrease of the function to find the interval of increase or decrease, we have to first find the critical points.

Critical points are points at which the derivative of the function is zero or undefined.

Therefore, we have to differentiate the function f(x) = x² - 6x - 95.

Applying the power rule of differentiation,

we have f'(x) = 2x - 6Setting f'(x) = 0, we have:

2x - 6 = 0x = 3At x = 3, the function attains a minimum.

Therefore, we have the following intervals:

The function is decreasing on the interval (-∞, 3) and is increasing on the interval (3, ∞).

To know  more about intercept

https://brainly.com/question/26233

#SPJ11

Twelve measurements of the percentage of water in a methanol solution yielded a sample mean Q = 0.547 and a sample standard deviation 0 =0.032. (a) Find a 95% confidence interval for the percentage of water in the methanol solution. (b) Explain what exactly it means when we say that we are "95% confident" that the true mean u is in this interval.

Answers

We can say with 95% confidence that the true mean percentage of water in the methanol solution falls between 0.528 and 0.566.

To find the 95% confidence interval for the percentage of water in the methanol solution, we first need to find the margin of error. This can be calculated as 1.96 times the standard deviation divided by the square root of the sample size, which in this case is 12.
Margin of error = 1.96 x (0.032 / sqrt(12)) = 0.019
Next, we can use the sample mean and the margin of error to construct the confidence interval
Confidence interval = sample mean +/- margin of error
Confidence interval = 0.547 +/- 0.019
Confidence interval = (0.528, 0.566)
Therefore, we can say with 95% confidence that the true mean percentage of water in the methanol solution falls between 0.528 and 0.566.
When we say that we are "95% confident" that the true mean u is in this interval, it means that if we were to repeat the same experiment multiple times and construct 95% confidence intervals each time, approximately 95% of those intervals would contain the true population mean. It is important to note that this does not mean that there is a 95% chance that the true mean falls within this specific interval – rather, either the true mean falls within this interval or it doesn't, and we have a 95% chance of constructing an interval that captures the true mean.

To know more about standard deviation visit :

https://brainly.com/question/30298007

#SPJ11

Determine if the following statements are true or false. Justify your choice. a. If f(x,y) is continuous over the region R = [a, b] [c, d), then So (x,y)dydx = sa f(x,y)dxdy -22 b. Les dydx = 13S

Answers

a. The given statement of double integration "If f(x, y) is continuous over the region R = [a, b] [c, d), then ∬R f(x, y) dydx = ∬R f(x, y) dxdy - 22" is false.  

The equation implies that the double integral of f(x, y) over the region R in the order dy dx is equal to the double integral in the order dx dy minus 22. However, the constant term -22 seems arbitrary and unrelated to the integration process.

There is no mathematical justification for subtracting 22 from one side of the equation. Without any additional information or context, this statement is not valid.

           

b. The statement "∬R dy dx = 13S" is incomplete and cannot be determined as true or false without further clarification.

The expression "13S" is ambiguous and lacks context. It is unclear what "S" represents, and the meaning of the equation is unknown.

To evaluate the truth value of this statement, we need additional information or a precise definition of "S" and its relationship to the double integral over the region R. Without that clarification, it is impossible to determine whether the statement is true or false.

Learn more about double integral here:

https://brainly.com/question/2289273

#SPJ11








Find the first four non-zero terms of the Taylor series for f(x) = 16,7 centered at 16. ..

Answers

The first four non-zero terms of the Taylor series for f(x)=16.7 centered at x=16 are all equal to 16.7.

What is the Taylor series?

The Taylor series is a way to represent a function as an infinite sum of terms, where each term is a multiple of a power of the variable x and its corresponding coefficient. The Taylor series expansion of a function f(x) centered around a point a is given by:

[tex]f(x)=f(a)+f'(a)(x-a)+f"(a)\frac{(x-a)^2}{2!}+f'"(a)\frac{(x-a)^3}{3!}+f""(a)\frac{(x-a)^4}{4!}+...[/tex]

To find the Taylor series for the function f(x)=16.7 centered at x=16, we can use the general formula for the Taylor series expansion of a function.

The formula for the Taylor series expansion of a function f(x) centered at x=a is given by:

[tex]f(x)=f(a)+f'(a)(x-a)+f"(a)\frac{(x-a)^2}{2!}+f'"(a)\frac{(x-a)^3}{3!}+f""(a)\frac{(x-a)^4}{4!}+...[/tex]

Since the function f(x)=16.7 is a constant, its derivative and higher-order derivatives will all be zero. Therefore, the Taylor series expansion will only have the first term f(a) with all other terms being zero.

Plugging in the value a=16 and f(a)=16.7, we have:

f(x)=16.7

The Taylor series expansion for f(x)=16.7 centered at x=16 will be: 16.7

Therefore, the first four non-zero terms of the Taylor series for f(x)=16.7 centered at x=16 are all equal to 16.7.

To learn more about  the Taylor series from the given link

brainly.com/question/28168045

#SPJ4

I need help with question 39

Answers

Answer:

e = 5.25 , f = 4.5

Step-by-step explanation:

since the triangles are similar then the ratios of corresponding sides are in proportion , that is

[tex]\frac{DF}{AC}[/tex] = [tex]\frac{EF}{BC}[/tex] ( substitute values )

[tex]\frac{e}{7}[/tex] = [tex]\frac{3}{4}[/tex] ( cross- multiply )

4e = 7 × 3 = 21 ( divide both sides by 4 )

e = 5.25

and

[tex]\frac{DE}{AB}[/tex] = [tex]\frac{EF}{BC}[/tex] , that is

[tex]\frac{f}{6}[/tex] = [tex]\frac{3}{4}[/tex] ( cross- multiply )

4f = 6 × 3 = 18 ( divide both sides by 4 )

f = 4.5

please solve
2. Determine the nth term for a sequence whose first five terms are 28 26 - 80 24 242 120 and then decide whether the sequence converges or diverges.

Answers

The nth term of the sequence is: [tex]an^2 + bn + c = -58n^2 + 296n - 210[/tex] for the given question.

The first step to determine the nth term of the sequence is to look for a pattern or a rule that relates the terms of the sequence. From the given terms, it is not immediately clear what the pattern is. However, we can try to find the difference between consecutive terms to see if there is a consistent pattern in the differences. The differences between consecutive terms are as follows:-

2 -106 104 -218 122 We can see that the differences are not constant, so it's not a arithmetic sequence. However, if we look at the differences between the differences of consecutive terms, we can see that they are constant. In particular, the second differences are all equal to 208.

Therefore, the sequence is a polynomial sequence of degree 2, which means it has the form[tex]an^2 + bn + c[/tex]. We can use the first three terms to form a system of three equations in three unknowns to find the coefficients. Substituting n = 1, 2, 3 in the formula [tex]an^2 + bn + c[/tex], we get:

a + b + c = 28 4a + 2b + c = 26 9a + 3b + c = -80 Solving the system of equations, we get a = -58, b = 296, c = -210. Therefore, the nth term of the sequence is: an² + bn + c = [tex]-58n^2 + 296n - 210[/tex].

To decide whether the sequence converges or diverges, we need to look at the behavior of the nth term as n approaches infinity. Since the leading coefficient is negative, the nth term will become more and more negative as n approaches infinity. Therefore, the sequence diverges to negative infinity.


Learn more about sequence here:

https://brainly.com/question/30262438


#SPJ11

Study the diagram of circle C.
A circumscribed angle, ∠PQR,
is tangent to ⨀C
at points P
and R,
and ∠PCR
is a central angle. Point Y
lies on the major arc formed by points P
and R.
Circle C as described in the text.

© 2016 StrongMind. Created using GeoGebra.

If m∠PQR=(12x−2)∘,
and mPR⌢=(20x−10)∘,
what is m∠PQR?
Responses

16∘
16 degrees

137.5∘
137.5 degrees

81∘
81 degrees

70∘

Answers

The measure of ∠PQR is approximately 101°.

To find the measure of angle ∠PQR, we can set up an equation using the information given.

From the problem, we know that m∠PQR = (12x - 2)° and mPR⌢ = (20x - 10)°.

Since ∠PQR is an inscribed angle and PR is a tangent, we can apply the inscribed angle.

According to the measure of an inscribed angle is half the measure of its intercepted arc.

The intercepted arc in this case is the major arc formed by points P and R.

Since Y lies on this arc, we can say that the intercepted arc measures 360° - mPR⌢.

We have the equation:

m∠PQR = 0.5 × (360° - mPR⌢)

Plugging in the given values, we get:

(12x - 2)° = 0.5 × (360° - (20x - 10)°)

Simplifying the equation:

12x - 2 = 0.5 × (360 - 20x + 10)

12x - 2 = 0.5 × (370 - 20x)

12x - 2 = 185 - 10x

22x = 187

x ≈ 8.5

Now we can find the measure of ∠PQR by substituting the value of x back into the expression:

m∠PQR = (12x - 2)°

= (12 × 8.5 - 2)°

≈ 101°

For similar questions on measure

https://brainly.com/question/25716982

#SPJ8

Which of the following is NOT a requirement for testing a claim about a population mean with σ known? Choose the correct answer below O A. Either the population is normally distributed or n > 30 or both. O B. The sample mean, x is greater than 30 O C. The value of the population standard deviation is known. O D. The sample is a simple random

Answers

The correct option is B. The sample mean, x, being greater than 30 is not a requirement for testing a claim about a population mean with σ known.

In hypothesis testing for a population mean with a known standard deviation, the key requirements are:

A. Either the population is normally distributed or n > 30 (or both): This requirement ensures that the sampling distribution of the sample mean approaches a normal distribution, which is necessary for conducting hypothesis tests and using critical values or p-values.

C. The value of the population standard deviation is known: This requirement is essential because when the population standard deviation (σ) is known, it is used in the calculation of the test statistic and the determination of the critical values.

D. The sample is a simple random sample: This requirement ensures that the sample is representative of the population and helps to avoid bias and confounding factors.

Option B, stating that the sample mean, x, is greater than 30, is not a requirement for testing a claim about a population mean with a known standard deviation. The sample mean itself does not need to satisfy any specific condition; instead, it is used in the calculation of the test statistic and the determination of the confidence interval or p-value.

To know more about population mean,

https://brainly.com/question/13977577

#SPJ11

24. [-/1 Points] DETAILS SCALCET9 5.XP.2.011.MI. Express the limit as a definite integral on the given interval. n lim Σx; ln(1 + x; ²) Ax, [0, 4] n→[infinity] i=1 SC dx

Answers

The limit [tex]\( \lim_{n\to\infty} \sum_{i=1}^n x_i \ln(1+x_i^2)\Delta x_i \)[/tex] can be expressed as the definite integral [tex]\( \int_0^3 f(x) dx \)[/tex].

To express the given limit as a definite integral, we start by rewriting the limit in summation notation:

[tex]\[ \lim_{n \to \infty} \sum_{i=1}^n x_i \ln(1+x_i^2) \Delta x_i \][/tex]

where [tex]\( \Delta x_i \)[/tex] represents the width of each subinterval. We want to express this limit as a definite integral on the interval [0, 3].

Next, we need to determine the expression for [tex]\( x_i \)[/tex] and [tex]\( \Delta x_i \)[/tex] in terms of [tex]\( n \)[/tex] and the interval [0, 3]. Since we are partitioning the interval [0, 3] into [tex]\( n \)[/tex] subintervals of equal width, we can set:

[tex]\[ \Delta x_i = \frac{3}{n} \][/tex]

To find the value of [tex]\( x_i \)[/tex] at each partition point, we can use the left endpoints of the subintervals, which can be obtained by multiplying the index [tex]\( i \)[/tex] by [tex]\( \Delta x_i \)[/tex]:

[tex]\[ x_i = \frac{3}{n} \cdot i \][/tex]

Substituting these expressions into the original summation, we have:

[tex]\[ \lim_{n \to \infty} \sum_{i=1}^n \left(\frac{3}{n} \cdot i\right) \ln\left(1 + \left(\frac{3}{n} \cdot i\right)^2\right) \cdot \frac{3}{n} \][/tex]

Simplifying further, we can write:

[tex]\[ \lim_{n \to \infty} \frac{9}{n^2} \sum_{i=1}^n i \ln\left(1 + \frac{9i^2}{n^2}\right) \][/tex]

This summation represents a Riemann sum. As [tex]\( n \)[/tex] approaches infinity, this Riemann sum approaches the definite integral of the function [tex]\( f(x) = x \ln(1+x^2) \)[/tex] over the interval [0, 3].

Therefore, the original limit can be expressed as the definite integral:

[tex]\[ \int_0^3 x \ln(1+x^2) dx \][/tex]

This represents the accumulation of the function [tex]\( f(x) = x \ln(1+x^2) \)[/tex] over the interval [0, 3].

The complete question must be:

Express the limit as a definite integral on the given interval.

[tex]\[\lim_{{n \to \infty}} \sum_{{i=1}}^n x_i \ln(1+x_i^2) \Delta x_i \quad \text{{as}} \quad \int_{{0}}^{{3}} (\_\_\_) \, dx\][/tex]

Learn more about limit :

https://brainly.com/question/12383180

#SPJ11










Submit Answer 22. [0/1 Points] DETAILS PREVIOUS ANSWERS Evaluate \ / + (x - 2y + z) ds. S: z = 6 - X, 0 sxs 6, Osy s5 67 Х Need Help? Read It

Answers

To evaluate the given line integral ∫√(1 + (x - 2y + z)^2) ds over the curve S: z = 6 - x, 0 ≤ x ≤ 6, 0 ≤ y ≤ 5, we need to parameterize the curve and calculate the corresponding line integral.

We start by parameterizing the curve S. Since z = 6 - x, we can rewrite the curve as a parametric equation: r(t) = (t, y, 6 - t), where 0 ≤ t ≤ 6 and 0 ≤ y ≤ 5.

Next, we need to calculate the length element ds. For a parametric curve, ds is given by ds = ||r'(t)|| dt, where r'(t) is the derivative of r(t) with respect to t. In this case, r'(t) = (1, 0, -1), so ||r'(t)|| = √(1^2 + 0^2 + (-1)^2) = √2.

Now, we substitute the parameterization and the length element into the line integral:

∫√(1 + (x - 2y + z)^2) ds = ∫√(1 + (t - 2y + 6 - t)^2) √2 dt.

Simplifying the integrand, we have ∫√(1 + (6 - 2y)^2) √2 dt.

Finally, we evaluate this integral over the given interval 0 ≤ t ≤ 6, taking into account the range of y (0 ≤ y ≤ 5), to obtain the value of the line integral.

In conclusion, to evaluate the line integral ∫√(1 + (x - 2y + z)^2) ds over the given curve, we parameterize the curve, calculate the length element ds, substitute into the line integral expression, and evaluate the resulting integral over the specified interval.

To learn more about parameterize: -/brainly.com/question/14762616#SPJ11

Let
ak = 3k + 4 and bk = (k − 1)3 + 2k + 5
for every integer
k ≥ 0.
What are the first five terms defined by
ak?
a0
=
a1
=
a2
=
a3
=
a4
=
What are the first five terms defined by
bk?
b0
=
b1
=
b2
=
b3
=
b4
=
Do the first five terms of these two sequences have any terms in common?
Yes. Only the first term in both sequences are identical.Yes. Only the first two terms in both sequences are identical. Yes. Only the first three terms in both sequences are identical.Yes. Only the first four terms in both sequences are identical.Yes. The first five terms of both sequences are identical.No. These two sequences have no terms in common.

Answers

The first five terms defined by ak are:

a0 = 4

a1 = 7

a2 = 10

a3 = 13

a4 = 16

The first five terms defined by bk are:

b0 = 5

b1 = 8

b2 = 13

b3 = 20

b4 = 29

Among the first five terms of these two sequences, only the first term, a0, and the second term, a1, are identical. So Yes, only the first two terms in both sequences are identical.

We can calculate the terms of the sequences by substituting the given values of k into the expressions for ak and bk. By evaluating the expressions for the first five values of k, we obtain the corresponding terms for each sequence.

Upon comparing the terms of the two sequences, we observe that only the first two terms, a0 and a1, are the same. The remaining terms, starting from the third term onward, differ between the sequences. Therefore, the first five terms of these two sequences have only the first two common terms .

To know more about  sequences click on below link:

https://brainly.com/question/30262438#

#SPJ11

A man starts walking south at 5 ft/s from a point P. Thirty minute later, a woman starts waking north at 4 ft/s from a point 100 ft due west of point P. At what rate are the people moving apart 2 hours after the man starts walking?

Answers

The rate at which the people are moving apart 2 hours after the man starts walking is 0 ft/s.

Let's set up a coordinate system to solve the problem. We'll place point P at the origin (0, 0) and the woman's starting point at (-100, 0). The man starts walking south, so his position at any time t can be represented as (0, -5t).

The woman starts walking north, so her position at any time t can be represented as (-100, 4t).

After 2 hours (or 2 * 3600 seconds), the man's position is (0, -5 * 2 * 3600) = (0, -36000), and the woman's position is (-100, 4 * 2 * 3600) = (-100, 28800).

To find the distance between them, we can use the distance formula:

Distance = √((x2 - x1)^2 + (y2 - y1)^2)

where (x1, y1) and (x2, y2) are the coordinates of the two points.

Distance = √((-100 - 0)^2 + (28800 - (-36000))^2)

        = √(10000 + 12960000)

        = √(12970000)

        ≈ 3601.2 feet

To find the rate at which the people are moving apart, we need to find the rate of change of distance with respect to time. We differentiate the distance equation with respect to time:

d(Distance)/dt = d(√((x2 - x1)^2 + (y2 - y1)^2))/dt

Since the x-coordinates of both people are constant (0 and -100), their derivatives with respect to time are zero. Therefore, we only need to differentiate the y-coordinates:

d(Distance)/dt = d(√((0 - (-100))^2 + ((-36000) - 28800)^2))/dt

              = d(√(100^2 + (-64800)^2))/dt

              = d(√(10000 + 4199040000))/dt

              = d(√(4199050000))/dt

              = (1/2) * (4199050000)^(-1/2) * d(4199050000)/dt

              = (1/2) * (4199050000)^(-1/2) * 0

              = 0

Therefore, the rate at which the people are moving apart 2 hours after the man starts walking is 0 ft/s.

To know more about rate refer here:

https://brainly.com/question/25565101#

#SPJ11

Problem 10 The logistic equation may be used to model how a rumor spreads through a group of people. Suppose that p(t) is the fraction of people that have heard the rumor on day t. The equation dp 0.2p(1-P) dt describes how p changes. Suppose initially that one-tenth of the people have heard the rumor; that is, p(0) - = 0.1. 1. (4 points) What happens to p(t) after a very long time? 2. (3 points) At what time is p changing most rapidly?

Answers

After a very long time, p(t) approaches a stable value or equilibrium. This is because the logistic equation accounts for a limiting factor (1 - p) that restricts the growth of p(t) as it approaches 1. As t tends to infinity, the term 0.2p(1 - p) approaches 0, resulting in p(t) stabilizing at the equilibrium value.

To find the time at which p(t) is changing most rapidly, we need to find the maximum value of the derivative dp/dt. We can differentiate the logistic equation with respect to t and set it equal to zero to find the critical point:

dp/dt = 0.2p(1 - p) = 0

This equation implies that either p = 0 or p = 1. However, since p(t) represents the fraction of people, p cannot be equal to 0 or 1 (since some people have heard the rumor initially). Therefore, the maximum rate of change occurs at an interior point.

To determine the time at which this happens, we need to solve the logistic equation for dp/dt = 0. Since the equation is non-linear, it may require numerical methods or approximation techniques to find the specific time at which p(t) is changing most rapidly.

To know more about derivative click on below link:

https://brainly.com/question/29144258#

#SPJ11

How much would each 30 student need to contribute if the total contribution is $ 30,000?​

Answers

Answer: 1000 dollars each

Step-by-step explanation: Assuming each student is providing an equal amount of money, which we are forced to with the lack of context, it's a simple division problem of 30,000 divided by 30, with 30 to represent the amount of students and 30,000 the total contribution. Using the Power Of Ten Rule, 10 x 1000 is 10,000, so 30 x 1,000 is 30,000, and therefore 30000 divided by 30 is 1,000

Please explain clearly thank you
1 Choose an appropriate function and center to approximate the value V using p2(x) Use fractions, not decimals! f(x)= P2(x)= P. (6)

Answers

To approximate the value V using the function P2(x), we need to choose an appropriate center and function. In this case, the function f(x) is given as f(x) = P2(x) = P.

The choice of center depends on the context of the problem and the values involved. Since we don't have specific information about the context or the value of V, we'll proceed with a general explanation.First, let's assume that the center of the approximation is c. The function P2(x) represents a polynomial of degree 2, which means it can be expressed as P2(x) = a(x - c)^2 + b(x - c) + d, where a, b, and d are coefficients to be determined.

To find the coefficients, we need additional information about the function f(x) or the value V. Without such information, we can't provide specific values for a, b, and d or determine the center c. Hence, we can't provide a precise answer or express it in terms of fractions.

In conclusion, to approximate the value V using the function P2(x), we need more specific information about the function f(x) or the value V itself. Once we have that information, we can determine the appropriate center and calculate the coefficients of the polynomial function P2(x)(Note: As the question doesn't provide any specific values or constraints, the explanation is based on general principles and assumptions.)

To learn more about polynomial function click here:

brainly.com/question/29054660

#SPJ11

Convert the rectangular equation to an equation in cylindrical coordinates and spherical coordinates. x2 + y2 +z2 = 216 (a) Cylindrical coordinates (b) Spherical coordinates

Answers

(a) Cylindrical coordinates r² + z² = 216

(b) Spherical coordinates r² = 216/ sin² φ

The rectangular equation x² + y² + z² = 216 can be converted into cylindrical coordinates and spherical coordinates as follows:

(a) Cylindrical coordinates

In cylindrical coordinates, x = r cos θ, y = r sin θ, and z = z.

Substituting these values in the given equation, we get:

r² cos² θ + r² sin² θ + z² = 216

=> r² + z² = 216

This is the equation in cylindrical coordinates.

(b) Spherical coordinates

In spherical coordinates,

x = r sin φ cos θ,

y = r sin φ sin θ, and

z = r cos φ.

Substituting these values in the given equation, we get:

r² sin² φ cos² θ + r² sin² φ sin² θ + r² cos² φ = 216

=> r² (sin² φ cos² θ + sin² φ sin² θ + cos² φ) = 216

=> r² = 216/ sin² φ

This is the equation in spherical coordinates.

To learn more about cylindrical coordinates, refer:-

https://brainly.com/question/31434197

#SPJ11

If | $(x) = F(x) +c, then = f(x) is the integral of F(x) + c. F(x) + c is the integral of f(x). F(x) is the integrand. O O cis the constant of the differentiation. f() is the integrand. O cis the constant of the integration. Exactly one of the above is true.

Answers

The correct statement is that F(x) + c is the integral of f(x) because it represents the antiderivative of f(x) plus a constant term.

When we integrate a function f(x), we obtain an antiderivative F(x), which is often referred to as the indefinite integral. However, since the process of integration involves an arbitrary constant, we add "+ c" to indicate that there are infinitely many antiderivatives of f(x), all differing by a constant value.

So, the expression f(x) = F(x) + c represents the antiderivative of f(x) plus a constant term. This is because when we differentiate F(x) + c, the constant term differentiates to zero, leaving us with the derivative of F(x), which is equal to f(x). Thus, F(x) + c is indeed the antiderivative of f(x).

In summary, the statement "F(x) + c is the integral of f(x)" is true. The other options are not accurate representations of the relationship between the integral and the antiderivative.

The complete question is:

""If F(x) + c = ∫f(x) dx, then which of the following statements is true?

F(x) + c is the integral of f(x).

F(x) is the integrand.

c is the constant of integration.

f(x) is the integrand.

Exactly one of the above is true.""

Learn more about integral:

https://brainly.com/question/30094386

#SPJ11

a) (12 points) Let E be the solid that is enclosed by the planes z = 0 and x + y - z = 1. Evaluate the following triple integral: (2x + y − 1) dV. E

Answers

The triple integral (2x + y - 1) dV over E is equal to zero. To evaluate the triple integral (2x + y - 1) dV over the solid E enclosed by the planes z = 0 and x + y - z = 1, we need to determine the limits of integration for each variable.

The plane z = 0 represents the xy-plane, and the plane x + y - z = 1 can be rearranged as x + y - z - 1 = 0. This equation represents a plane intersecting the xy-plane at z = 1.

To find the limits of integration, we need to consider the region of intersection between the planes.

Setting z = 0 in the equation x + y - z = 1, we have x + y - 0 - 1 = 1, which simplifies to x + y = 2. This represents a line in the xy-plane.

Setting z = 1 in the equation x + y - z = 1, we have x + y - 1 - 1 = 1, which simplifies to x + y = 3. This represents another line in the xy-plane.

The region of intersection between x + y = 2 and x + y = 3 is an empty set since the lines are parallel and will never intersect. Therefore, the solid E enclosed by the planes z = 0 and x + y - z = 1 is an empty solid, and the integral over this solid will be zero.

Hence, the triple integral (2x + y - 1) dV over E is equal to zero.

To know more about triple integration refer here:

https://brainly.com/question/30404807?#

#SPJ11

please help ASAP. do everything
correct.
3. (10 pts.) Let / be the function defined by if x < -1, [2²³ +2² f(x)= ²+c+4 if-15I, where e is a constant. Find all values of c for which f is continuous at -1.

Answers

To find the values of c for which the function f is continuous at -1, we need to ensure that the left-hand limit and the right-hand limit of f at x = -1 exist and are equal.

First, let's find the left-hand limit of f at x = -1. Since f(x) is defined differently for x < -1 and -15 ≤ x ≤ -1, we need to evaluate the limit separately for each interval.

For x < -1, we have f(x) = 2^(23 + 2^(c + 4)). Taking the limit as x approaches -1 from the left side, we can substitute x = -1 into the expression:

lim(x→-1-) 2^(23 + 2^(c + 4))

Next, let's find the right-hand limit of f at x = -1. For -15 ≤ x ≤ -1, we have f(x) = 2^(c + 4). Taking the limit as x approaches -1 from the right side, we substitute x = -1:

lim(x→-1+) 2^(c + 4)

To ensure the function f is continuous at x = -1, the left-hand limit and the right-hand limit must be equal. Thus, we set up the equation:

lim(x→-1-) 2^(23 + 2^(c + 4)) = lim(x→-1+) 2^(c + 4)

To solve this equation, we'll simplify the left-hand side first:

lim(x→-1-) 2^(23 + 2^(c + 4)) = 2^(23 + 2^(c + 4))

Now, let's solve the equation:

2^(23 + 2^(c + 4)) = 2^(c + 4)

Since the bases are the same, we can equate the exponents:

23 + 2^(c + 4) = c + 4

Simplifying further, we have:

2^(c + 4) - c = 19

Unfortunately, it's not possible to find an algebraic solution for this equation. However, we can use numerical methods or approximation techniques to find an approximate value for c that satisfies the equation.

To learn more about continuous function visit:

brainly.com/question/31851316

#SPJ11

5. The net monthly profit (in dollars) from the sale of a certain product is given by the formula P(x) = 106 + 106(x - 1)e-0.001x, where x is the number of items sold. Find the number of items that yi

Answers

The number of items that yield the maximum net monthly profit can be found by analyzing the given formula P(x) = 106 + 106(x - 1)e^(-0.001x), where x represents the number of items sold.

To determine this value, we need to find the critical points of the function.

Taking the derivative of P(x) with respect to x and setting it equal to zero, we can find the critical points.

After differentiating and simplifying, we obtain

[tex]P'(x) = 0.001(x - 1)e^{-0.001x}- 0.001e^{(-0.001x)}[/tex]

To solve for x, we set P'(x) equal to zero:

[tex]0.001(x - 1)e^{(-0.001x)} - 0.001e^{(-0.001x)} = 0[/tex]

Factoring out [tex]0.001e^{-0.001x}[/tex] from both terms, we have

[tex]0.001e^{-0.001x}(x - 1 - 1) = 0[/tex]

Simplifying further, we get:

[tex]e^{-0.001x}(x - 2) = 0[/tex]

Since [tex]e^{-0.001x}[/tex] is always positive, the critical point occurs when (x - 2) = 0.

Therefore, the number of items that yields the maximum net monthly profit is x = 2.

To learn more about profit visit:

brainly.com/question/17337604

#SPJ11

Consider the curve parameterized by: x = 2t³/2 - 1 and y = 5t. a. (6 pts) Find an equation for the line tangent to the curve at t = 1. b. (6 pts) Compute the total arc length of the curve on 0 ≤ t ≤ 1.

Answers

The total arc length of the curve on 0 ≤ t ≤ 1 is given by the integral ∫[0 to 1] √[9t⁴/4 + 25] dt.

To find the equation of the tangent line to the curve at t = 1, we need to compute the derivatives dx/dt and dy/dt. Taking the derivatives of the given parameterization, we have dx/dt = 3t^(1/2) and dy/dt = 5. Evaluating these derivatives at t = 1, we find dx/dt = 3 and dy/dt = 5.

The slope of the tangent line at t = 1 is given by the ratio dy/dt over dx/dt, which is 5/3. Using the point-slope form of a line, where the slope is m and a point (x₁, y₁) is known, we can write the equation of the tangent line as y - y₁ = m(x - x₁). Plugging in the values y₁ = 5(1) = 5 and m = 5/3, we obtain the equation of the tangent line as y - 5 = (5/3)(x - 1), which can be simplified to 3y - 15 = 5x - 5.

To compute the total arc length of the curve for 0 ≤ t ≤ 1, we use the formula for arc length: L = ∫(a to b) √(dx/dt)² + (dy/dt)² dt. Plugging in the derivatives dx/dt = 3t^(1/2) and dy/dt = 5, we have L = ∫(0 to 1) √(9t)² + 5² dt. Simplifying the integrand, we get L = ∫(0 to 1) √(81t² + 25) dt.

To evaluate this integral, we need to find the antiderivative of √(81t² + 25). This can be done by using appropriate substitution techniques or integration methods. Once the antiderivative is found, we can evaluate it from 0 to 1 to obtain the total arc length of the curve.

Note: Without further information about the specific form of the antiderivative or additional integration techniques, it is not possible to provide a numerical value for the total arc length. The exact computation of the integral depends on the specific form of the function inside the square root.

Learn more about integral here:

https://brainly.com/question/31059545

#SPJ11

Let A = (0, 0, −3, 0) and B = (2, −1, −2, 1) be points in Rª (Use <,,,> notation for your vector entry in this question.) a. Determine the vector AB. help (vectors) b. Find a vector in the direction of AB that is 2 times as long as AB. help (vectors) c. Find a vector in the direction opposite AB that is 2 times as long as AB. help (vectors) d. Find a unit vector in the direction of AB. help (vectors) e. Find a vector in the direction of AB that has length 2.

Answers

Let A = (0, 0, −3, 0) and B = (2, −1, −2, 1) be points in Rª. (A) a vector in the direction of AB that is 2 times as long as AB is (4, -2, 2, 2), (B)  a vector in the direction of AB that is 2 times as long as AB is (4, -2, 2, 2). (C)  a vector in the direction opposite AB that is 2 times as long as AB is (-4, 2, -2, -2),

a. To determine the vector AB, we subtract the coordinates of point A from the coordinates of point B.

AB = B – A = (2, -1, -2, 1) – (0, 0, -3, 0) = (2, -1, 1, 1).

Therefore, the vector AB is (2, -1, 1, 1).

b. To find a vector in the direction of AB that is 2 times as long as AB, we simply multiply each component of AB by 2.

2AB = 2(2, -1, 1, 1) = (4, -2, 2, 2).

Therefore, a vector in the direction of AB that is 2 times as long as AB is (4, -2, 2, 2).

c. To find a vector in the direction opposite AB that is 2 times as long as AB, we multiply each component of AB by -2.

-2AB = -2(2, -1, 1, 1) = (-4, 2, -2, -2).

Therefore, a vector in the direction opposite AB that is 2 times as long as AB is (-4, 2, -2, -2).

d. To find a unit vector in the direction of AB, we need to normalize AB by dividing each component by its magnitude.

Magnitude of AB = sqrt(2^2 + (-1)^2 + 1^2 + 1^2) = sqrt(7).

Unit vector in the direction of AB = AB / |AB| = (2/sqrt(7), -1/sqrt(7), 1/sqrt(7), 1/sqrt(7)).

Therefore, a unit vector in the direction of AB is (2/sqrt(7), -1/sqrt(7), 1/sqrt(7), 1/sqrt(7)).

e. To find a vector in the direction of AB that has a length of 2, we need to multiply the unit vector in the direction of AB by 2.

2 * (2/sqrt(7), -1/sqrt(7), 1/sqrt(7), 1/sqrt(7)) = (4/sqrt(7), -2/sqrt(7), 2/sqrt(7), 2/sqrt(7)).

Therefore, a vector in the direction of AB that has a length of 2 is (4/sqrt(7), -2/sqrt(7), 2/sqrt(7), 2/sqrt(7)).

Learn more about  unit vector here:

https://brainly.com/question/28028700

#SPJ11

Find the directional derivative of the function at the given point in the direction of the vector v. f(x, y, z) = √√xyz, (3, 3, 9), v = (-1, -2, 2) Du(3, 3, 9) =

Answers

The directional derivative Du(3, 3, 9) of the function f(x, y, z) = √√xyz at the point (3, 3, 9) in the direction of the vector v = (-1, -2, 2) is -1/18.

To obtain the directional derivative of the function f(x, y, z) = √√xyz at the point (3, 3, 9) in the direction of the vector v = (-1, -2, 2), we can use the gradient operator and the dot product.

The directional derivative, denoted as Du, is given by the dot product of the gradient of the function with the unit vector in the direction of v. Mathematically, it can be expressed as:

Du = ∇f · (v/||v||)

where ∇f represents the gradient of f, · denotes the dot product, v/||v|| is the unit vector in the direction of v, and ||v|| represents the magnitude of v.

Let's calculate the directional derivative:

1. Obtain the gradient of f(x, y, z).

The gradient of f(x, y, z) is given by:

∇f = (∂f/∂x, ∂f/∂y, ∂f/∂z)

Taking partial derivatives of f(x, y, z) with respect to each variable:

∂f/∂x = (√(yz) / (2√(xyz))) * yz^(-1/2)

      = y / (2√xyz)

∂f/∂y = (√(yz) / (2√(xyz))) * xz^(-1/2)

      = x / (2√xyz)

∂f/∂z = (√(yz) / (2√(xyz))) * √(xy)

      = √(xy) / (2√(xyz))

So, the gradient of f(x, y, z) is:

∇f = (y / (2√xyz), x / (2√xyz), √(xy) / (2√(xyz)))

2. Calculate the unit vector in the direction of v.

To find the unit vector in the direction of v, we divide v by its magnitude:

||v|| = √((-1)^2 + (-2)^2 + 2^2)

     = √(1 + 4 + 4)

     = √9

     = 3

v/||v|| = (-1/3, -2/3, 2/3)

3. Compute the directional derivative.

Du = ∇f · (v/||v||)

  = (y / (2√xyz), x / (2√xyz), √(xy) / (2√(xyz))) · (-1/3, -2/3, 2/3)

  = -y / (6√xyz) - 2x / (6√xyz) + 2√(xy) / (6√(xyz))

  = (-y - 2x + 2√(xy)) / (6√(xyz))

Substituting the values (3, 3, 9) into the directional derivative expression:

Du(3, 3, 9) = (-3 - 2(3) + 2√(3*3)) / (6√(3*3*9))

           = (-3 - 6 + 6) / (6√(81))

           = -3 / (6 * 9)

           = -1/18

To know more about directional derivative refer here:

https://brainly.com/question/29451547#

#SPJ11

help me solve this and explain it

Answers

The value of x is:  x = 4, when the two figures have same perimeter.

Here, we have,

given that,

the two figures have same perimeter.

we know, that,

A perimeter is a closed path that encompasses, surrounds, or outlines either a two dimensional shape or a one-dimensional length. The perimeter of a circle or an ellipse is called its circumference. Calculating the perimeter has several practical applications.

Perimeter refers to the total outside length of an object.

1st triangle have: l = (2x + 5)ft and, l = 5x+1 ft , l = 3x+4

so, perimeter = l+l+l = 10x+10 ft

2nd rectangle have: l = 2x ft and, w = x+13 ft

so, perimeter = 2 (l + w) = 6x + 26 ft

so, we get,

10x+10 = 6x + 26

or, 4x = 16

or, x = 4

Hence, The value of x is:  x = 4, when the two figures have same perimeter.

Learn more about perimeter here:

brainly.com/question/397857

#SPJ1

Find the average value over the given interval. 10) y = e-X; [0,5]

Answers

The average value of the function y = e^(-x) over the interval [0, 5] can be found by evaluating the definite integral of the function over the interval and dividing it by the length of the interval.

First, we integrate the function:

[tex]∫(0 to 5) e^(-x) dx = [-e^(-x)](0 to 5) = -e^(-5) - (-e^0) = -e^(-5) + 1[/tex]

Next, we find the length of the interval:

Length of interval = 5 - 0 = 5

Finally, we calculate the average value:

Average value =[tex](1/5) * [-e^(-5) + 1] = (-e^(-5) + 1)/5[/tex]

Therefore, the average value of y = e^(-x) over the interval[tex][0, 5] is (-e^(-5) + 1)/5.[/tex]

Learn more about interval and dividing here:

https://brainly.com/question/20388837

#SPJ11

Given the following information about a computer programming, find the mistake in the program. Use the rules of inferences and/or logical equivalences. (15) a. There is an undeclared variable or there is a syntax error in the first five lines. b. If there is a syntax error in the first five lines, then there is a missing semicolon or a variable name is misspelled. e. There is not a missing semicolon. d. There is not a misspelled variable name

Answers

The following depicts the diagram of the logical steps for the program

a. ∃x(Undeclared(x) ∨ SyntaxError(x))

b. SyntaxError(x) → (MissingSemicolon(x) ∨ MisspelledVarName(x))

e. ¬MissingSemicolon(x)

d. ¬MisspelledVarName(x)

¬(MissingSemicolon(x) ∨ MisspelledVarName(x))

SyntaxError(x) → (MissingSemicolon(x) ∨ MisspelledVarName(x))

¬SyntaxError(x)

∴ ∃x(Undeclared(x))

How to explain the information

First, let's translate the statements into logical notation:

a. ∃x(Undeclared(x) ∨ SyntaxError(x))

b. SyntaxError(x) → (MissingSemicolon(x) ∨ MisspelledVarName(x))

e. ¬MissingSemicolon(x)

d. ¬MisspelledVarName(x)

We can now use the rules of inferences to find the mistake in the program.

From e and d, we can conclude that ¬(MissingSemicolon(x) ∨ MisspelledVarName(x)).

From b, we know that SyntaxError(x) → (MissingSemicolon(x) ∨ MisspelledVarName(x)).

Therefore, we can conclude that ¬SyntaxError(x).

Learn more about Program on

https://brainly.com/question/26642771

#SPJ1

Other Questions
an investor purchases a bond for 108.93 and sells it one year later at 107.30. the bond pays an annual coupon of 6% and has 10 years until maturity. if the par value of the bond is $30,000.00, what is the rate of return on the bond over year? my friend could write letter into passive voice into passive voice Having an entrepreneurial orientation towards the control of resources means:A. that one focuses on accessing others' resources.B. that one focuses on purchasing resources.C. that one has a belief that resources are unlimited and therefore easy to obtain.D. that one focuses on using a hierarchy management structure in allocating resources 13. The water depth in a harbour is 8m at low tide and 18m at high tide. High tide occurs at 3:00. One cycle is completed every 12 hours. Graph a sinusoidal function over a 24 hour period showing wate Which of the following uses three types of participants: decision-makers, staff personnel, and respondents?a. Executive opinionsb. Salesforce compositec. Delphi methodd. Consumer surveyse. Time series analysis The area of a square Park and a rectangular park is the same. The side length of the square Park is 60m and the length of the rectangular park is 90m. What is the breadth of the rectangular park? one of the key elemtns in the political landscape of kacksonian america was the upsurge of universal white male suffrage, 1. [-11 Points] DETAILS HARMATHAP12 13.2.0 Evaluate the definite integral. 7 Dz.dz - dz Need Help? Read It Watch It Submit Answer Find all Laurent series of 1 (-1) (-2) with center 0. select the two ways in which microorganisms acquire antimicrobial resistance Select the default constructor signature for a Student class. public Student) private Student() O public void Student() private void Student() (1 point) find the function g(x) satisfying the two conditions: 1. g(x)=512x3 2. the maximum value of g(x) is 3. Sketch the graph of the function f defined byy=sqrt(x+2)+2, not by plotting points, but by starting with the graph of a standard function and applying steps of transformation. Show every graph which is a step in the transformation process (and itsequation) on the same system of axes as the graph of f. If two events A and B are independent, then which of the following must be true? Choose all of the answers below that are correct. There may be more than one correctanswer.Choosing incorrect statements will lower your score on this question.OA. P(AIB)=P(A)O b. P(A or B) = P(A)P(B)O c. P(A/B)-P(B) d. P(A and B) = P(A)+P(B) In the dividend-growth model, increases in stock value are associated with: Increases in the growth rate and dividends; decreases in the required rate of return. Increases in the required rate of retu In the late 19th century, Giovanni Schiaparelli observed the planet Mars with a telescope. He detected lines across the surface of Mars, which he called"channels." This word was translated into English as "canals." Then, the astronomer Percival Lowell drew maps depicting a fake Martian civilization. Laterobservations with better telescopes showed that there are no canals on Mars. How was scientific knowledge of Mars open to change?O A New evidence could also be interpreted as canals.8. New evidence showed Martian civilization was possible.OC. New evidence did not support the earlier interpretations of observations.OD. New evidence was insufficient to confirm or deny the earlier observations. 7PROBLEM 2 Compute the following 2x a) sin(x) dx 2 b) ** sin(e) de Are these two answers the same? Explain why or why not. incoterms rules determine o how much the agents commission will be. how much duty will be charged by the importing country. where the goods change ownership from exporter to importer. which country will collect the duty on the goods. The demand function for a commodity is given by D(z) = = 2000 - 0.1z - 1.01z. Find the consumer surplus when the sales level is 100. Round your answer to the nearest cent. .1. Given that an array of int named a has been declared with 12 elements and that the integer variable k holds a value between 2 and 8.Assign 22 to the element just before a[k] .2.Given that an vector of int named a has been declared with 12 elements and that the integer variable k holds a value between 0 and 6.Assign 9 to the element just after a[k] .3. Given that an vector of int named a has been declared, and that the integer variable n contains the number of elements of the vector a , assign -1 to the last element in a .