Primitive of Exponential of a x by Cosine of b x

Theorem

 * $\displaystyle \int e^{a x} \cos b x \rd x = \frac {e^{a x} \paren {a \cos b x + b \sin b x}} {a^2 + b^2} + C$

Also see

 * Primitive of $e^{a x} \sin b x$