Question

X varies directly as the cube root of y .x=6when y=8.Find the value of x when y=64.

Answer 1

The value of x is 12.

Explanation:

Given that x is directly proportional to y so the expression will be x = k (³√y) where k is the constant. First, you have to find the value of k :

`x = k \: (\sqrt[3]{y} )`

`let \: x = 6,y = 8`

`6 = k \: (\sqrt[3]{8} )`

`6 = k(2)`

`k = 3`

Next, you have to find the value of x, by substituting y = 64 into the expression :

`x = 3 \: ( \sqrt[3]{y} )`

`x = 3( \sqrt[3]{64} )`

`x = 3(4)`

`x = 12`