What is the constant of variation for the quadratic variation?

x 2 3 4 5 6
y 20 45 80 125 180
A. 5
B. 10
C. 15
D. 25

Question

What is the constant of variation for the quadratic variation?
 
x	2	3	4	5	6
y	20	45	80	125	180
A. 5
B. 10
C. 15
D. 25

bloomlocke367 · Answer

Do you know what the constant of variation is? Like, what it's asking you?

anonymous · Answer

not really

bloomlocke367 · Answer

Since k is constant (the same for every point), we can find k when given any point by dividing the y-coordinate by the x-coordinate. For example, if y varies directly as x , and y = 6 when x = 2 , the constant of variation is k  = 3 . Thus, the equation describing this direct variation is y = 3x

igreen · Answer

Wait..it says 'quadratic variation

igreen · Answer

I believe that's represented by y = kx^2

bloomlocke367 · Answer

yes.

igreen · Answer

Let's plug in 5 for 'k' and 2 for 'x' and see if we get 20 for 'y'.

$y = kx^2$

$y = (5)(2^2)$

What's 2^2? @bcimkenz

anonymous · Answer

4

anonymous · Answer

@iGreen

igreen · Answer

Yes, and what's 5 * 4?

anonymous · Answer

20

igreen · Answer

Yes, so 5 fits as the constant of variation, so 5 is our answer.