Question

If y varies inversely as the cube of x and x=2.5 when y=0.015, how do you find y when x=5?

Answer 1

`y=.001875` when `x=5`

Explanation:

`y prop 1/x^3 or y = k* 1/x^3 ; x =2.5` when `y =0.015 :. 0.015= k* 1/2.5^3 or k = 2.5^3 *0.015 =0.234375` So the variation equation stands `y= 0.234375*1/x^3` Now putting `x=5` we get `y= 0.234375 *1/5^3 = .001875`[Ans]