Evaluate int_0^pi(2+ sinx)dx?

1 Answer
Nov 29, 2016

int_0^pi(2+ sinx)dx = 2pi+2

Explanation:

You should learn that;

d/dx sinx = cosx iff int cosx dx = sinx + c
d/dx cosx = -sinx iff int sinx = -cosx + c

So

int_0^pi(2+ sinx)dx = [2x - cosx]_0^pi
\ = (2pi - cospi) - (2*0-cos0)
\ = (2pi - (-1)) - (0-1)
\ = 2pi+1 +1
\ = 2pi+2