Showing posts with label Integration by parts. Show all posts
Showing posts with label Integration by parts. Show all posts

Friday, March 20, 2009

Integrating Log Value by Parts Method

Topic : Integration by Parts
Question : Integrate by Parts x . ln (x)

Solution :
∫ x . ln (x) dx
take u = ln (x) and dv = x dx
we know ∫ u dv = uv - ∫v du
u = ln x
dv = x dx
v = ∫dv = ∫x dx = x²/2
uv - ∫v du
= (ln x)(x²/2) - ∫x/2 . 1 dx
(u = ln x so du = 1/x dx)
= x²/2 . ln x - ∫x/2 dx + c
= x²/2 . ln x - 1/2 . x²/2
= x²/2 . ln x - x²/4 + c