Question

write a specific formula to describe the variation: x varies directly with the cube root of y; x = 3 when y = 125

Answer 1

x = k(y^1/3)
3 = k(125^1/3)
3 = 5k
k = 3/5

Therefore, x = (3/5)(y^(1/3))

Answer 2

Thats what I thought. This question has choices with it.

x = - 5/ cbrt(y)
x = 5 / cbrt(y)
x = 15/cbrt(y)
x = - 15 / cbrt(y)
I get that the numerator is cbrt(y). But I got 3/5 for the numerator

Answer 3

I do NOT see any error in what I did. If you see an error, please tell me where that is. I just dont see it.

Answer 4

The cube root of y is represented by y^(1/3)
varying directly with the cube root of y is k(y^(1/3))

Answer 5

And I subsituted and solved correctly, from what I see.