Integrate x*ln(x)

This example provides us with a better understanding of how "Integration by parts" works. Building an extensive knowledge of Integral calculus requires a lot of work, but once the basics are fully understood, it follows naturally that one would go into a more deep approach.

Recall: ∫fg′=fg−∫f′g (Integration by parts), where f and g are well-defined functions

Approach:

1) Think before you act

2) Think two steps ahead

3) Be clear and not verbose

Solution:

 ∫xlnx dx=

= ∫ [(x^2)/2]' lnx dx=

= [(x^2)/2]lnx - ∫[(x^2)/2] (lnx)' dx=

= [(x^2)/2]lnx - 1/2∫(x^2)*(1/x) dx=

= [(x^2)/2]lnx - 1/2∫xdx=

= [(x^2)/2]lnx - 1/2 * (x^2)/2   +C (don't forget the constant)=

= (simple manipulation) [(x^2)(2lnx -1)]/4 +C

Now remember, Maths can be very easy once you take action. The best car in the world will not take you to the right place if you don't know where you want to go. #naturalenthusiasm

MM
Answered by Maximilian M. Maths tutor

6830 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Differentiate F(x)=(25+v)/v


How do you integrate sin(3x)cos(5x)?


A uniform ladder is leaning against a smooth wall on a rough ground. The ladder has a mass of 10 kilograms and is 4 metres long. If the ladder is in equilibrium, state an equation for the coefficient of friction of the ground


How many solutions are there to the equation sin x = a, if 0<a<1 and 0<x<pi


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2026 by IXL Learning