Find the equation of the tangent of x^2- xy + y^2 =7 at (-1, 2)
Answer:
It is 3y = 4x + 10
Step-by-step explanation:
Let's first get the slope of the curve.
[ slope is the derivative of the equation ]
[tex] {x}^{2} - xy + {y}^{2} = 7[/tex]
introduce dy/dx :
[tex] \frac{d}{dx} ( {x}^{2} - xy + {y}^{2} ) = \frac{d}{dx} (7) \\ \\ 2x - (y + \frac{dy}{dx} ) + 2y \frac{dy}{dx} = 0[/tex]
make dy/dx the subject:
[tex]2x - y - \frac{dy}{dx} + 2y \frac{dy}{dx} = 0 \\ \\ 2y \frac{dy}{dx} - \frac{dy}{dx} = y - 2x \\ \\ \frac{dy}{dx} (2y - 1) = y - 2x \\ \\ \frac{dy}{dx} = \frac{y - 2x}{2y - 1} [/tex]
At point (-1, 2):
[tex] \frac{dy}{dx} = \frac{2 - 2( - 1)}{2(2) - 1} \\ \\ slope = \frac{4}{3} [/tex]
but a tangent has the same slope as the curve:
[tex]y = mx + c[/tex]
m is the slope
c is the y-intercept
At (-1, 2):
[tex]2 = ( - 1 \times \frac{4}{3} ) + c \\ \\ c = 2 + \frac{4}{3} \\ \\ c = \frac{10}{3} [/tex]
equation:
[tex]y = \frac{4}{3} x + \frac{10}{3} \\ \\ { \boxed{3y = 4x + 10}}[/tex]
Answer:
Step-by-step explanation:
Here is an other way:
z=f(x,y)=x²-xy+y²-7=0
[tex]\dfrac{\partial f(x,y)}{\partial x} =2x-y\\\\\dfrac{\partial f(x,y)}{\partial y} =-x+2y\\\\\\\dfrac{dy}{dx} =-\dfrac{\dfrac{\partial f(x,y)}{\partial x} }{\dfrac{\partial f(x,y)}{\partial y}} =-\dfrac{2x-y}{-x+2y} \\\\(-1;2)\\Slope=-\dfrac{2*(-1)-2}{1+2*2} =\dfrac{4}{5} \\\\y-2=\frac{4}{5} (x+1)\\\\\\\boxed{y=\dfrac{4x}{5} +\dfrac{14}{5} }[/tex]
what is equivalent expression to 0.112 - 16/75 A -0.112 + 16/75 B -0.112 (-16)/75 C 0.112 + (-16)/75
Answer:
C
Step-by-step explanation:
0.112 + (-16)/75 is equivalent to 0.112 - 16/75
This is finding the midpoint. Please help
Answer:
hence the required midpoint of the given line is (9,5)
Answer:
[tex]( \frac{6 + 2}{2} +\frac{12 + 8}{2}) = ( \frac{8}{2} + \frac{20}{2} ) = (4 \: comma10)[/tex]
The answer is :(4, 10)
The population of a city is increasing 4% per year and is now 7,200. If it continues to increase at the same rate, what will the population be after 3 years?
Answer:
A = 7200(1.04)^3
A = 8099
Step-by-step explanation:
After a cleanup, algae covers 2 miles of a coastline. The length of the coastline covered after the cleanup is $\frac{1}{3}$
1
3 of the previous length. How many miles of the coast did the algae previously cover?
The miles previously covered by algae is 6 miles
let m represent the miles of the coastline covered by algae before the clean-up
fraction of miles covered after the clean-up = [tex]\frac{1}{3}[/tex] x m = [tex]\frac{1}{3}m[/tex]
miles covered after the clean-up = 2 miles
[tex]\frac{1}{3}m[/tex] = 2 miles
to determine the value of m, make m the subject of the formula.
To do this, take the following step :
multiply both sides of the equation by 2
m = 2 miles x 3
m = 6 miles
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Simplify (ab)(ab)(ab)(ab).
ab 4
a 4b 4
4ab
Answer:
[tex] {a}^{4} {b}^{4} [/tex]
Step-by-step explanation:
[tex](ab) \times (ab) \times (ab) \times (ab)[/tex]
[tex] {a}^{1 + 1 + 1 + 1} {b}^{1 + 1 + 1 + 1} [/tex]
[tex] = {a}^{4} {b}^{4} [/tex]
giải phương trình :
-4x-8x>0
Answer:
[tex]x < 0[/tex]
Step-by-step explanation:
[tex] - 4x - 8x > 0[/tex]
➡️ [tex] - 12x > 0[/tex]
➡️ [tex]x < 0[/tex]
16d+23=14(d−2) what does d=
Answer:
Answer: d is -25.5
Step-by-step explanation:
[tex]16d + 23 = 14(d - 2)[/tex]
open brackets:
[tex]16d + 23 = 14d - 28[/tex]
collect d terms together:
[tex]16d - 14d = - 28 - 23 \\ 2d = - 51 \\ d = - 25.5[/tex]
Which expression is NOT equivalent to 60 + 18?
6(10+3)
6(10+4)
3(20 + 6
2(30 +9)
Answer:
6(10+4)
Step-by-step explanation:
The real question gives 78
Expand all the brackets in the option
and compare if it gives the answer real expression i.e 78
Please help me with this!
Answer:
p=-7
Step-by-step explanation:
-11+10(p+10)=4-5(2p+11)
Firstly, expand the bracket
-11+10p+100=4-10p-55
Next, you collect like terms
10p+10p=4-55-100+11
20p=-140
Divide through by the coefficient of p
20p/20=-140/20
p=-7
DECIDE!!!!!!!!!!!!!!!!!!!!!!
Answer:
Step-by-step explanation:
DA,DG,DC are tangents of the circles so have the same length.
NB: F is the orthocenter of triangle HDF
Find the product of 6/4 × 12/5
Answer:
18/5
Step-by-step explanation:
6/4 x 12/5
18/5
Highlight the correct symbol.
<, >, =
1,404,000 ________ 1,040,000
Answer:
>
Step-by-step explanation:
1,404,000 > 1,040,000
Help help help help help help help help help help help plsss
Write an equation for the situation then solve for x. After paying $7 for a sandwich, John has $11. With how much money did he start?
(I know the answer to the question but the steps on how to solve for x confuse me)
Answer:
x = 18
Step-by-step explanation:
total money = money spent + money left
x = 7+11
x = 18
The following table shows the amount of money earned by the key club from a car wash. Use the table to determine what the rate of change is if the amount of money made is dependent on the number of cars washed.
Answer:
Can u help me
Step-by-step explanation:
With my maths question
A cookie factory makes 8 types of cookies. Each day, the factory makes 1,093 of each type of cookie. How many cookies does the factory make each day?
Answer:
8744 cookies
Step-by-step explanation:
8 × 1093
.........
9. Maria usually pays $3.10 per pound for her favorite granola. Which of the answers below is
a better deal?
A. 2 pounds for $6.49
B. 3 pounds for $10
C. 5 pounds for $14.75
D. 8 pounds for $28
What’s the answer
Answer:
c
Step-by-step explanation:
The answer is C. To find the answer all you need to do is divide the money per pound for each option until you find the lowest deal.
A is not a good deal because its about $3.14 for a pound
B is not a good deal because its about $3.33 per pound
D is not a good deal because its $3.50 per pound
C IS a good deal because it's $2.95 per pound
Answer:
c
Step-by-step explanation:
The answer is C. To find the answer all you need to do is divide the money per pound for each option until you find the lowest deal.
A is not a good deal because its about $3.14 for a pound
B is not a good deal because its about $3.33 per pound
D is not a good deal because its $3.50 per pound
C IS a good deal because it's $2.95 per pound
Lamar works as a tutor for $12 an hour and as a waiter for $14 an hour. This month, he worked a combined total of 100 hours at his two jobs.
Let "t" be the number of hours Lamar worked as a tutor this month. Write an expression for the combined total dollar amount he earned this month.
total earned (in dollars) =__________
Answer:
-2t + 1400
Step-by-step explanation:
If t represents the number of hours Lamar worked as a tutor, the number of hours he worked as a waiter can be represented by 100 - t.
Create an equation to represent the situation:
12t + 14(100 - t) = total earned
Simplify:
12t + 1400 - 14t = total earned
-2t + 1400 = total earned
So, the expression for the amount he earned is -2t + 1400
Ben took part in a 45km bicycle race.Ben cycled at a speed of v km/h for the entire race.Express the time taken by Ben in terms of v.
Answer:
(45/v) hours
Step-by-step explanation:
that is the answer yep
Answer:
45/v =t
Step-by-step explanation:
Cuz the normal formula is
V= d/t
Therefore
t= d/v
And u know D = 45km so..
t=45/v
Divide the following integers.
helllp please
-12 � 4=
-3
-8
-48
3
Answer:
-48Step-by-step explanation:
-12 × 4
= -48
#Let'sLearnAnswer:
[tex] - 12 \times 4 \\ \\ = - 48[/tex]
it's was helpful to you
if (2x,3y) =(8, 9),find x and y
Answer:
x = 4, y = 3
Step-by-step explanation:
Equating corresponding coordinates , gives
2x = 8 ( divide both sides by 2 )
x = 4
and
3y = 9 ( divide both sides by 3 )
y = 3
Expand [tex](x-\frac{1}{x} )^{12}[/tex] , simplifying the coefficients
Help with algebra 1
(A-y)^2 +2y^3
If a=3 and y=-2
PLEASE HELP WILL GIVE BRAINLIEST ASAP! I REALLY NEED HELP WITH PART B ESPECIALLY
Part A: Find a rational number that is between 9.5 and 9.7. Explain why it is rational. (2 points)
Part B: Find an irrational number that is between 9.5 and 9.7. Explain why it is irrational. Include the decimal approximation of the irrational number to the nearest hundredth.
Answer:
Step-by-step explanation:
9.59277626267 is irrational.
Because it has many ifinite decimals
which properties says that x+(y+3) =x(3+y)
Answer:
Commutative property
Step-by-step explanation:
addition is commutative for example 2+3=3+2
multiplication is also commutative 3*2=2×3
Points a, b and c are collinear point b is between a and c find the length indicated
Points A , B and C are collinear......
The water was pumped out of a backyard pond. What is the domain of this graph
Answer:
D. Real numbers from 0 to 12
Step-by-step explanation:
The domain is the possible x-values and because the depth can not go below 0, the amount of time stops at 12.
Time also can not go below 0 so we are left with real numbers from 0 to 12
Find tan A of a RIGHT TRIANGLE with side lengths b = 8 and c = 12
2(3m+6n) + 3(5m-2n)+ 5(-6m+n)
Answer:
[tex]2(3m + 6n) + 3(5m - 2n) + 5( - 6m + n) \\ [/tex]
open the brackets:
[tex] = (6m + 12n) + (15m - 6n) + ( - 30m + 5n) \\ [/tex]
group the coefficients of m and n in their brackets:
[tex] = (6 + 15 - 30)m + (12 - 6 + 5)n \\ [/tex]
then operate the brackets:
[tex] = - 9m + 11n[/tex]