# Thread: QUICK!!! I need Help with my indefinite integrals!!!!

1. ## QUICK!!! I need Help with my indefinite integrals!!!!

Hi!! I have two problems that I'm trying to solve, I've found the solution to the first one, but have no idea how to show work for it!!! Please help if you can!!!!

1) (x^2)/(x+1) dx

2) cos(x)2^(sin(x)) dx

2. Originally Posted by sarah133
Hi!! I have two problems that I'm trying to solve, I've found the solution to the first one, but have no idea how to show work for it!!! Please help if you can!!!!

1) (x^2)/(x+1) dx
note that $\displaystyle \frac {x^2}{x + 1} = \frac {x^2 - 1 + 1}{x + 1} = \frac {x^2 - 1}{x + 1} + \frac 1{x + 1} = x - 1 + \frac 1{x + 1}$

and you should be able to integrate that

2) cos(x)2^(sin(x)) dx
do a substitution of $\displaystyle u = \sin x$, you will end up with $\displaystyle \int 2^u~du$ which you should be able to handle. then just back-substitute when done

3. ## still a little confused....

thanks that helps alot!!!

but what do I do when I get to the

4. Originally Posted by sarah133
thanks that helps alot!!!

but what do I do when I get to the