# Thread: General Formula For Variation 2

1. ## General Formula For Variation 2

Write a general formula to describe each variation. Let k be the constant of proportionality for each variation.

1. T varies jointly with the cube root of x and the square of d.

T = cuberoot{x}(d^2)k

2. z varies directly with the sum of the cube of x and the square of y.

z = (x^3 + y^2)k

3. The cube of z varies directly with the sum of the squares of x and y.

z^3 = (x^2 + y^2)k

Is any of this correct?

2. ## Re: General Formula For Variation 2

Yep all good. Same comment as MarkFL gave, usually k is put at the front of the expression.

3. ## Re: General Formula For Variation 2

Originally Posted by Debsta
Yep all good. Same comment as MarkFL gave, usually k is put at the front of the expression.
For the most part, I did well in Section 2.5 of the Sullivan textbook. We move on to Chapter 3, Section 3.1 or Functions.