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

Theorem
Let $a \in \R_{>0}$ be a strictly positive real constant.

Let $x \in \R$.

Then:
 * $\displaystyle \int \frac {\d x} {x^2 - a^2} = \begin {cases} \dfrac 1 {2 a} \map \ln {\dfrac {a - x} {a + x} } + C & : \size x < a\\

& \\ \dfrac 1 {2 a} \map \ln {\dfrac {x - a} {x + a} } + C & : \size x > a \\ & \\ \text {undefined} & : \size x = a \end {cases}$

Also see

 * Primitive of $\dfrac 1 {x^2 + a^2}$
 * Primitive of $\dfrac 1 {a^2 - x^2}$: Logarithm Form