How do you integrate int (cosx)(coshx) using integration by parts?

1 Answer
Apr 11, 2018

below

Explanation:

I = int \ cosx \ coshx \ dx

= int \ cosx \ d(sinh x)

= cosx sinh x - int \ d( cosx) \ sinh x

= cosx sinh x + int sin x \ sinh x \ dx

= cosx sinh x + int sin x \ d(cosh x)

= cosx sinh x + (sin x cosh x - int \ d(sin x )\ cosh x)

= cosx sinh x + sin x cosh x - I

implies I = 1/2 ( cosx sinh x + sin x cosh x) + C