Evaluate ∫−∞∞e−ax2dx\int_{-\infty}^{\infty} e^{-ax^2} dx∫−∞∞e−ax2dx.
πa\sqrt{\frac{\pi}{a}}aπ
πa\sqrt{\pi a}πa
πa\frac{\pi}{a}aπ
aπ\sqrt{\frac{a}{\pi}}πa