Primitives involving Root of x squared plus a squared

Theorem
This page gathers together the primitives of some expressions involving $\sqrt {x^2 + a^2}$.

Also see

 * Primitives involving $\paren {\sqrt {x^2 + a^2} }^3$


 * Primitives involving $\sqrt {x^2 - a^2}$
 * Primitives involving $\sqrt {a^2 - x^2}$