Thread: Indefinite integrals

I'm very confused about this section. Apparently I need to use the substitution rule but I always seem to mess up, especially with fractions. Can anyone help?

Here's an example:

Integral of: x/sqrt x+1


From what I understand you set x+1 = u
you then take the derivative of u which is 1 and set that equal to u'
From here I tend to mess up...

Originally Posted by Yami Sorceress

I'm very confused about this section. Apparently I need to use the substitution rule but I always seem to mess up, especially with fractions. Can anyone help?

Here's an example:

Integral of: x/sqrt x+1


From what I understand you set x+1 = u
you then take the derivative of u which is 1 and set that equal to u'
From here I tend to mess up...

.

So the integral becomes and you should be able to integrate each term. Then substitute back .