How do you find the antiderivative of (cosx)/(x) ?

1 Answer
Jun 28, 2016

ln x-(1/2)sum(-1)^nx^(2n)/(n(2n)!)+C, n=1, 2, 3,...,

and 0 < x<=1 .

Explanation:

cos x/x = sum((-1)^nx^(2n-1))/(2n)!, n=0, 1, 2, 3, .., .for non-zero x.

int cos x /x dx= int sum((-1)^nx^(2n-1))/(2n)!, n=0, 1, 2, 3, .., and# 0

< x<=1#.

=ln x-(1/2)sum(-1)^nx^(2n)/(n(2n)!)+C, n=1, 2, 3,...,

and 0 < x<=1 .