# Evaluating Indefinite integrals

1. Feb 7, 2008

### n77ler

1. The problem statement, all variables and given/known data
Evaluate

$$\oint x^2 (1-x^3)^6 dx$$

2. Relevant equations

3. The attempt at a solution

let u= 1-x^3
du= -3x^2
-1/3 du= x^2 dx
-1/3 $$\oint (u)^6$$
= -1/3 (u^7/7)
= -1/21 (1-x^3)^7 + C

Is this done correct? I think I followed all the right steps but there is something about it that has me wondering.
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Feb 7, 2008

### HallsofIvy

Staff Emeritus
the only problem I see is that circle on your integral symbol!

What do you get if you differentiate -(1/21)(1-x3)7+ C?

3. Feb 7, 2008

### n77ler

Yeah, the circle isn't supposed to be there I couldnt find a normal Integration sign.