# Math Help - Which methods to use to find the integrals.

1. ## Which methods to use to find the integrals.

I'm trying to find the indefinite integrals for the two equations below. What methods do I use to solve?

(-1 < x < 1)

Thanks

2. ## Re: Which methods to use to find the integrals.

The first one can be solved by integration by parts, let $u = arctan x, dv = 2x^3 + x$
Second one can be done easily by a substitution of $u = 1 - x^2$

3. ## Re: Which methods to use to find the integrals.

Originally Posted by jennybee
I'm trying to find the indefinite integrals for the two equations below. What methods do I use to solve?

(-1 < x < 1)

Thanks
For the first one use integration by parts

$u=\tan^{-1}(x) \quad dv=2x^3+x$

For the 2nd one use a u du substitution

$u=1-x^2$

4. ## Re: Which methods to use to find the integrals.

Thanks to both of you. Loving the Sephiroth avatar