Integrate (cosx)^3

In order to integrate (cosx)^3, there is no given rule (by-parts, 'try' method, chain rule) which we can follow. We would need to split it into (cosx)^2 and cosx. Then use the identity: (sinx)^2 + (cosx)^2 = 1. The function we are now integrating should look like this: (1-(sinx)^2)(cosx). Expand the brackets. Once the brackets have been expanded, cosx can be integrated to give sinx. Then we can use the 'try' method to integrate cosx(sinx)^2. 

SS

Related Maths A Level answers

All answers ▸

Find the turning point of y = x + 1 + 4/x2 and describe the nature of the turning point


Use the substition u = cos(x) to find the indefinite integral of -12sin(x)cos^3(x) dx


Using the factor theorem, factorise x^4 - 3x^3 - 3x^2 + 11x - 6


A general function f(x) has the property f(-x)=-f(x). State a trigonometric function with this property and explain using the Maclaurin series expansion for this function why this property holds. Write down the integral in the limits -q to q of f(x) wrt x