# Math Help - anti derivative?????????

1. ## anti derivative?????????

x/(x+1)

i let u=x+1
so x=u-1

x+1-ln x +c

x - ln x +c

what happened to the 1????

2. ## Re: anti derivative?????????

Originally Posted by sluggerbroth
x/(x+1)

i let u=x+1
so x=u-1

x+1-ln x +c

x - ln x +c

what happened to the 1????
Both are correct. Notice that 1 + constant is still a constant.

I am not sure how you could get x + 1 - ln|x| + C though...

3. ## Re: anti derivative?????????

Hint: $\frac{x}{x+1} = 1 - \frac{1}{x+1}$.