Express sin(5theta) in terms of sin(theta) and powers of sin(theta) only.

Consider the expression (cos(theta) + i*sin(theta))5 . (Where theta a real parameter).By De Moirve's theorem, we know this expression is equivalent to cos(5theta) + i sin(5theta).We can also apply the binomial expansion to this expression and sort into real and imaginary components.We can then equate these two expressions we have found and compare imaginary components to obtain the required solution.This is best written out by hand.

PF
Answered by Peter F. Further Mathematics tutor

5438 Views

See similar Further Mathematics A Level tutors

Related Further Mathematics A Level answers

All answers ▸

A rectangular hyperbola has parametric equations x = 4t, y = 4/t , (z non 0). Points P and Q on this hyperbola have parameters t = 1/4 and t = 2. Find the equation of the line l which passes through the origin and is perpendicular to the line PQ.


Using graphs, show how the Taylor expansion can be used to approximate a trigonometric function.


Find the first three non-zero terms of the Taylor series for f(x) = tan(x).


Prove by mathematical induction that, for all non-negative integers n, 11^(2n) + 25^n + 22 is divisible by 24


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