I need help on calc 2

Question

find integral

 

integral of x cos x dx

Answer 1

∫x cos x dx

 

Using integration by parts

Let u = x       and  dv = cos x dx

du/dx = 1     and v = sin x

 

∫x cos x dx = x sin x - ∫sin x dx

 

= x sin x - (-cos x) + c

= x sin x + cos x + c