Y is directly proportional to x^2. It could be represented by the expression:
y α x^2
We can make it into an equality by inserting the proportionality constant, k.
y = kx^2
k would be constant for any value of y with a corresponding value of x. We solve the problem by this concept as follows:
y1/(x1)^2 = y2/(x2)^2
10/(x1)^2 = y2/(x1/2)^2
10/4 = y2
Therefore, when the value of x is halved, y is equal to 10/4.