# Thread: Integration by substitute problem

1. ## Integration by substitute problem

I have function which I have to solve with substitution rule:

I try to substitute u = x +1

When I get:

I know the answer, Integration function is:

But I don't get it, what is wrong with my substitution?

2. $\displaystyle \frac{{\left( {u - 1} \right)^2 - 1}}{{\sqrt u }} = \frac{{u^2 - 2u}}{{\sqrt u }} = u^{\frac{3}{2}} - 2u^{\frac{1}{2}}$