number (ii) derivation

Derive the following reduction formulae : x sin" - 1 x cos x sin" x (i) 1 1 = x sin" x dy = - n - 1 n 2 n n "n - 2 [Hints : Choose first function = x sin" - x ] x cos n - 1 x sin x cos" x n - 1 (ii) In = x cos" x dx = 2 + n n - 2 n