Evaluate ∫−∞∞1x2+2x+5dx\int_{-\infty}^{\infty} \frac{1}{x^2+2x+5} dx∫−∞∞x2+2x+51dx.
π/2\pi/2π/2
π/4\pi/4π/4
π\piπ
π/8\pi/8π/8