# Thread: Which method of integration is appropriate here?

1. ## Which method of integration is appropriate here?

How would you integrate 1 / (v+v^3) ?

I thought it would be [ 1 / (1+3v^2)] ln |v+v^3| by anti-differentiation but I don't think that is correct?

Thanks!

2. Originally Posted by kselogatr
How would you integrate 1 / (v+v^3) ?

I thought it would be [ 1 / (1+3v^2)] ln |v+v^3| by anti-differentiation but I don't think that is correct?

Thanks!
Use a partial fraction decomposition. If you need more help, please show all your work and say where you get stuck.

(It is obvius that your answer is wrong. Differentiate it - Do you get back 1/(v + v^3) ....?)

3. It appears that you tried to do this:

so that you could use a u substitution.

This is incorrect because you can only pull constants out of the integral, not functions.

Like Mr F said, factorise the denominator then use partial fractions. You should find that your answer has a logarithm term and an arctangent term.