2
$\begingroup$

I know that you can integrate

$$\int e^{-x}\cos(x)dx$$

by parts, but I would like to know how you can use complex variables instead.

  • 0
    Use Euler's formula to express $\cos x$ in terms of complex exponentials.2012-02-05
  • 0
    Re integration by parts -- is that possible for this integral? I don't see how that would work.2012-02-05
  • 0
    @Ben I think it is possible to integrate this by parts. In general it is possible to integrate $\int e^{ax} \cos bx \mathrm d x$ by parts. The same is true when $\cos bx$ is replaced by $\sin bx$.2012-02-05

1 Answers 1