Question

Are my answers correct?

Answer 1

Variable y varies directly with x2, and y = 96 when x = 4.

What is the value of y when x = 2?
answer= 48

Answer 2

Yes they are all correct.

Answer 3

Variable y varies directly with x2, and y = 196 when x = 7.

Enter the constant of variation in the quadratic variation equation.
y = 4 x2

Answer 4

y varies directly with x^2 implies y = k * x^2
when x = 4, y = 96
96 = k * (4)^2 = 16k
k = 96/16 = 6

y = 6x^2
when x = 2, y = 6 * (2)^2 = 6 * 4 = 24.

Answer 5

for the first one?

Answer 6

yes.

Answer 7

yes the second one is correct

Answer 8

ok, what about this one
Variable y varies directly with x2, and y = 48 when x = 4.

Which graph represents the quadratic variation?

Answer 9

Yes, the constant of variation is 4 for the second one.

Answer 10

I choose the 4th one

Answer 11

@aum or anyone else..

Answer 12

Not correct.

First find the constant of variation.
y = k * x^2
when x = 4, y = 48.
What is k?

Answer 13

192

Answer 14

How? Show your work.

Answer 15

i just times 4 to 48

Answer 16

y = k * x^2 ---- equation (1)
when x = 4, y = 48
put x = 4 and y = 48 in first equation and solve for k.

Answer 17

16k

Answer 18

Earlier in the thread we have solved two other similar problems.
Use the exact same method.
If you learn to solve this problem just once you can answer all similar problems on your own.

Answer 19

Put both the x and y values into equation (1) and then solve for k.

Answer 20

48 = k * 4^2
48= 16k

Answer 21

correct. Therefore, k = ?

Answer 22

3

Answer 23

correct. So the equation is y = 3x^2.
when x = 1, y = ?

Answer 24

I am choosing x = 1 because all graphs have the point x = 1 on them.
So what is the y value when x = 1 in the equation y = 3x^2 ?

Answer 25

x2

Answer 26

We started with the equation y = kx^2
we solve for k as k = 3
so y = 3x^2 is the equation.
when x = 1, y = 3 * 1^2 = 3
Therefore, when x = 1, y = 3 which means the point (1,3) must be on the graph.

Which graph has the point (1,3) ON it?

Answer 27

the 2nd one

Answer 28

The second one says it has the point (1,0.5) on it. Not (1,3)

Answer 29

nvm the third one

Answer 30

Yes. Please close this question.

Answer 31

ok, thx