Question

Use the given information to find the unknown value:y varies directly as the square of x. When x = 2, then y = 12. Find y when 2 = 5.y =

Answer 1

The square of x is expressed as x²

y varies directly, so:

y ∝ x²

Make into an equation by introducing k, the constant of variation:

y = k x x²

y = kx²

To find k, use the condition given x = 2 when y = 12

k = y/x²

k = 12/4

k = 3

Thus y = 3x²

y = 3x5²

y = 75