A function y= f (x) satisfies f "(x) = - 1/x2 - π2 sin(πx) ; f '(B) = π+ 1/2 and f (A)=0. The value of f (1/2) is
(A) ln 2
(B) 1
(C) π/2 - ln 2
(D) 1 – ln 2
Correct Answer is: (B) 1
f ' (x) = 1/x + π cos(πx) + C
f ' (2) = 1/2 + π + C = 1/2 + π ⇒ C =0
f (x) = ln | x | + sin(πx) + C'
f (1) = C' = 0
f (x) = ln | x | + sin(πx)