# Homework Help: Show the integral of dx/(1-x^2/a^2)

1. Jan 19, 2012

### chris_0101

1. The problem statement, all variables and given/known data
Hi, I am having a bit of trouble visualizing the process of the following integral:

∫dx/(1-x^2/a^2)

The answer to this would be: atanh-1$\frac{x}{a}$

if someone could show me this, that would be greatly appreciated.

Thanks

2. Jan 19, 2012

### obafgkmrns

Substitute x/a = tanh θ and use the identity 1 - (tanh θ)^2 = 1/(cosh θ)^2.

3. Jan 19, 2012

### chris_0101

thanks for the tip, I managed to solve the question.