9231 P13 - Jun 2010 - Q5 - 8 marks
6582
Use de Moivre's theorem to show that
\(\sin 5 \theta=16 \sin ^{5} \theta-20 \sin ^{3} \theta+5 \sin \theta .\)
Hence find all the roots of the equation
\(32 x^{5}-40 x^{3}+10 x+1=0\)
in the form \(\sin (q \pi)\), where \(q\) is a positive rational number.
Solutions locked. Please sign in with access to view them.