This is LaTeX code:

[latex]
\int_{-\infty}^{\infty}\frac{(x-1)\cos(2x)}{x^2-4x+5}dx=\mathbf{Re}(\int_{-\infty}^{\infty}\frac{(z-1)e^{2zi}}{z^2-4z+5}dz)
[/latex]