(a) Use integration by parts to find ∫ x sin(3x) dx

The question asks for integration by parts. Therefore we need to differentiate one variable and integrate the other. First we need to decide which variable is going to be which. Algebra should always be differentiated instead of trigonometric functions if possible. Therefore take:u=x, dv/dx = sin(3x). Differentiate the first term and integrate the second term to give: du/dx =1, and v = -1/3 cos(3x) . Now apply the formulae: uv - ∫ (du/dx * v) dx . This will give us: -x/3 cos(3x) - - 1/3( ∫ cos(3x) dx ) . The answer will then be: -x/3 cos(3x) + 1/9 sin(3x) + c

Answered by George A. Maths tutor

7434 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Express Cosx-3Sinx in form Rcos(x+a) and show that cosx-3sinx=4 has no solution MEI OCR June 2016 C4


Using partial fractions, find f(x) if f'(x)=5/(2x-1)(x-3)


Express 9^3x + 1 in the form3^y ?


How would you integrate ln(x)


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 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences