Question

If y varies inversely as the square ofx, and y = 1/8 when x = 1, find y when x = 5

Answer 1

25/8

Explanation:

The question can be interpreted as

Y= k/x^2.......eqn(1)

Where k= constant if proportionality

y = 1/8 when x = 1,

Substitute, we have

1/8= k/(1)^2

1/8= 1/k

Cross multiply

K= 1/8

find y when x = 5

From eqn(1)

Y= k/x^2

Y= (1/8)/(5)^2

Y=1/8 ×25

Y= 25/8