Question

If y is directly propotional to x2 and the difference in the values of ywhen x=1 and x=3is 32,find the value of y when x=-2​

Answer 1

Step-by-step explanation:

Given y is directly proportional to x2, means there is a constant k so that y = k * x2.

 

For x = 1 y(1) = k and for x =3 y(3) =9k

Now y(3) - y(1) = 9k - k = 8k = 32

k = 4

 

The relationship is y = 4x2

 

For x = -2, y = 4 * (-2)2 = 16