Question

If y varies directly as x^2 and y = 72 when x =3, what is the value of y when x = 6?

Answer 1

Answer:288

Explanation:

If y varies directly as x^2

i.e y varies directly as x * x

and y =72, when x =3

therefore, 72 = k* 3*3 9 (where k is constant)

72=k9

k = 72/9

=8

The value of y, when x =6 will be

y = 8 * 6^2

8*36 = 288