Question

If y varies inversely as the cube root of x, and y = 12 when x = 8, how do you find y when x = 1?

Answer 1

`24`

Explanation:

Write the english as maths: `y prop1/root(3)x`

Change the variation to an equation by multiplying by a constant.

`y = k/root(3)x" we need to find a value for "k`

`k = root(3)x xx y = root(3)8 xx 12 = 2 xx 12 = 24`

Replace `k` with `24` to obtain the equation

`y = 24/root(3)x`

Now we can calculate y for any given x.

`y = 24/root(3)1 =24/1 =24`