## What is walli’s formula in integration ?

Walli’s Formula : If m,n $$\in$$ N & m, n $$\ge$$ 2, then (a)  $$\int_{0}^{\pi/2}$$ $$sin^nx$$dx = $$\int_{0}^{\pi/2}$$ $$cos^nx$$dx = $$(n-1)(n-3)….(1 or 2)\over {n(n-2)….(1 or 2)}$$ K where K = $$\begin{cases} \pi/2 & \text{if n is even}\ \\ 1 & \text{if n is odd}\ \end{cases}$$ (b)  $$sin^nx.cos^mx$$dx = \([(n-1)(n-3)….(1 or 2)][(m-1)(m-3)….(1 or 2)]\over {(m+n)(m+n-2)(m+n-4)….(1 or …