Primitive of Reciprocal of a squared minus x squared/Logarithm Form 1

Theorem

 * $\displaystyle \int \frac {\d x} {a^2 - x^2} = \frac 1 {2 a} \ln \size {\frac {a + x} {a - x} } + C$

where $\size x < a$.

Also see

 * Primitive of Reciprocal of $x^2 + a^2$
 * Primitive of Reciprocal of $x^2 - a^2$: Logarithm Form