# Homework Help: Can you integrate?

1. Aug 12, 2009

### perfectibilis

Integrate the following--->
{x3+1/(whole root over)x2+x}dx

2. Aug 12, 2009

### foxjwill

Do you mean $$\int \frac{x^3+1}{\sqrt{x^2+x}}\,dx$$ or $$\int \left(x^3+\frac{1}{\sqrt{x^2+x}}\right)dx?$$

Either way, the best thing to do is to start by completing the square in the denominator, then using a bunch of trig substitution stuff.

3. Aug 12, 2009

### Дьявол

x3+13=(x+1)(x2-x+1)
x2+x=x(x+1)

Is it enough help?

Last edited: Aug 13, 2009
4. Aug 12, 2009

### Staff: Mentor

Actually, x3 + 1 = (x + 1)(x2 - x + 1).

In any case, we still don't know exactly what the integrand is.

5. Aug 13, 2009

### perfectibilis

I mean the first image.

6. Aug 13, 2009

### Дьявол

Mark44 thanks for the correction.

perfectibilis start by writing x3+1 with

$$\sqrt{(x+1)^2(x^2-x+1)^2}$$

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