Integration by Parts Math Example 4

Follow the full solution, then compare it with the other examples linked below.

Example 4

easy
Find โˆซxcosโกxโ€‰dx\displaystyle\int x\cos x\,dx.

Solution

  1. 1
    u=xu = x, dv=cosโกxโ€‰dxdv = \cos x\,dx; du=dxdu = dx, v=sinโกxv = \sin x.
  2. 2
    xsinโกxโˆ’โˆซsinโกxโ€‰dx=xsinโกx+cosโกx+Cx\sin x - \int \sin x\,dx = x\sin x + \cos x + C.

Answer

xsinโกx+cosโกx+Cx\sin x + \cos x + C
One IBP application with the algebraic factor as uu yields an immediately integrable result.

About Integration by Parts

An integration technique based on the product rule: โˆซuโ€‰dv=uvโˆ’โˆซvโ€‰du\int u\,dv = uv - \int v\,du. Used when the integrand is a product of two functions.

Learn more about Integration by Parts โ†’

More Integration by Parts Examples