Skip to content
Exercise: Integration by Parts · Q19

Q.Evaluate ∫x2ex dx\displaystyle\int x^2e^x\,dx.

West Bengal WbchseTextbookSubjectiveImportance★★★★★
34% · 22/65 Questions
🔒 Locked · start free trial →

You're viewing a preview — the full solution, concept, methods & PYQ mapping are locked.

Start your 14-day free trial to unlock the full solution →

First pass: u=x2u=x^2 (du=2x dxdu=2x\,dx), dv=exdxdv=e^xdx (v=exv=e^x):

∫x2ex dx=x2ex−2∫xex dx.\int x^2e^x\,dx = x^2e^x-2\int xe^x\,dx.

Second pass, on ∫xex dx\int xe^x\,dx: u=xu=x (du=dxdu=dx), dv=exdxdv=e^xdx (v=exv=e^x):

∫xex dx=xex−∫ex dx=(x−1)ex+C.\int xe^x\,dx = xe^x-\int e^x\,dx = (x-1)e^x+C.

Combining: ∫x2ex dx=x2ex−2(x−1)ex+C=ex(x2−2x+2)+C\int x^2e^x\,dx=x^2e^x-2(x-1)e^x+C=e^x\big(x^2-2x+2\big)+C. …

Unlock everything free for 14 days

  • Full step-by-step solutions
  • Concept-first explanations
  • Methods, shortcuts & mistakes
  • PYQ mapping + timed mock tests

Full access for 14 days. No credit card required.