Ifi(r) f2(r) f3 (r) A, = a b. c where fi(r), f2 (r), f3 (r) are functions of r and a, b, c, d, e, f d e E fi(r) E f2 (r) 2 13 (r ) r=1 1=1 1=1 n constants, then a b C 71=1 e cos x 24 4 16. If f (x) = tan x sec 2x , then sin3 x 5- 4 5 I f ( x ) dx =