Question

Y is inversely proportional to square of x when y=10 and x=3 find value of y when x=1/2

Answer 1

y = 360

Explanation:

Given y is inversely proportional to x² then the equation relating them is

y =
`(k)/(x^2)` ← k is the constant of proportion

To find k use the condition y = 10 when x = 3 , then

10 =
`(k)/(3^2)` =
`(k)/(9)` ( multiply both sides by 9 )

90 = k

y =
`(90)/(x^2)` ← equation of proportion

When x =
`(1)/(2)` , then

y =
`(90)/(((1)/(2))^2 )` =
`(90)/((1)/(4) )` = 90 × 4 = 360