Primitive of Reciprocal of Root of x squared plus a squared/Logarithm Form/Corollary

Theorem

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

Also see

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