How do you integrate (sinx)^2?

(sinx)^2 (similarly to (cosx)^2) cannot be integrated in this form. There is a standard method to get past this though, which makes use of the cos double angle formula:cos(2x) = (cosx)^2 - (sinx)^2        = 1 - (sinx)^2 - (sinx)^2        = 1 - 2(sinx)^22(sinx)^2 = 1 - cos(2x) (sinx)^2 = 1/2 - (1/2)cos(2x)So the integral of '(sinx)^2' can instead be seen as the integral of '1/2 - (1/2)cos(2x)'.This is a much easier integral to work out, and using our knowledge of integrating (the integral of cos(2x) is (1/2)sin(2x)) the answer is:(1/2)x - (1/4)sin(2x) + cAs the integration here is indefinite (without limits) the constant of integration must be present (+c).This is a method which is very specific to sinx and cosx, specifically when they are put to even powers.

WW
Answered by Will W. Maths tutor

37926 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Find the integral of (sinxcos^2x) dx


How would I answer this question? Use factor theorem to show (x-2) is a factor of f(x) = 2x^3 -7x^2 +4x +4.


Find the values of x and y for which dy/dx = 0 in y= x^3 - 4x^2 - 3x +2


Prove the identity (sin2x)/(1+(tanx)^2) = 2sinx(cosx)^3


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:

© 2025 by IXL Learning