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

Related Further Mathematics A Level answers

All answers ▸

Find the general solution to the second order differential equation x'' - 2x' + x = e^(2t).


Find the eigenvalues and eigenvectors of the matrix M , where M{2,2} = (1/2 2/3 ; 1/2 1/3) Hence express M in the form PDP^-1 where D is a diagonal matrix.


Prove by induction that 11^n - 6 is divisible by 5 for all positive integer n.


How do I sketch the locus of |z - 5-3i | = 3 on an Argand Diagram?