Primitive of Reciprocal of a squared minus x squared/Inverse Hyperbolic Cotangent Form

Theorem

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

where $\size x > a$.

Also see

 * Primitive of $\dfrac 1 {x^2 - a^2}$: $\tanh^{-1}$ form for the case $\size x < a$