# Arccosh(x) integral

1. Sep 11, 2008

1. The problem statement, all variables and given/known data

$$\int$$dx/$$\sqrt{}x^2 -1$$
I actually know that the answer is arccosh(x) but I want to prove it in form of Ln(x+$$\sqrt{}x^2 -1$$)

2. Relevant equations

3. The attempt at a solution
I have tried many times such as u=x2-1 and u=x2

Last edited: Sep 11, 2008
2. Sep 11, 2008

### rocomath

Re: Integral

Did you mean ...

$$\int\frac{dx}{\sqrt{x^2-1}}$$

3. Sep 11, 2008

Re: Integral

Yes I mean

LaTeX Code: \\int\\frac{dx}{\\sqrt{x^2-1}}

4. Sep 11, 2008

### Defennder

Re: Integral

Use a trigo substitution here.

5. Sep 19, 2008