Let us denote with $W_n$ the Wallis integral, that is:
$$W_n=\int_0^{\pi/2} \sin^n x \, {\rm d}x$$
Prove that $W_n \sim \sqrt{\frac{\pi}{2n}}$.
Solution
$$W_n=\int_0^{\pi/2} \sin^n x \, {\rm d}x$$
Prove that $W_n \sim \sqrt{\frac{\pi}{2n}}$.
Solution
