Integrate x^2e^x with respect to x between the limits of x=5 and x=0.

This question is to test integration by parts.  First let u=x2 and u'=2x as a result, and v'=ex and so v=ex too. Then use the by parts formula to express the integral as x2ex​​​​​​​-2(integral of):(xex​​​​​​​-ex​​​​​​​)dx. Using the by parts method again with the integral we just found we can reduce the second expression to x2ex​​​​​​​-2xex​​​​​​​+2ex​​​​​​​. This is the indefinite integration result of the expression in question, (without the +c!) and the question is finished by first plugging 5 into the answer, to get 25e5-10e5​+2e5​ and then plugging in 0, to give just 2. Subtracting the lower limit from the upper limit results gives 25e5​-10e5​+2e5​-2, which is a constant term and is the answer to the question (in physical terms it is the area underneath the curve y=x2ex between the points x=0 and x=5)

Answered by Alex A. Maths tutor

4532 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Find the area between the curves C_1, C_2 and the lines x=0 and x=1, where C_1 is the curve y = x^2 and C_2 is the curve y = x^3.


R=1000e^-ct , it takes 5730 years for half of the substance to decay a. find the number of atoms at the start of the decay. b. calculate the number of atoms left when t=22920. c. sketch the function.


Integrate the function f(x)=lnx


How can I get better at Mathematics? I am struggling with confidence and achieving low grades.


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2024

Terms & Conditions|Privacy Policy