Edexcel P2 2021 January — Question 6

Exam BoardEdexcel
ModuleP2 (Pure Mathematics 2)
Year2021
SessionJanuary
TopicReciprocal Trig & Identities

  1. (a) Show that the equation
$$\frac { 3 \sin \theta \cos \theta } { 2 \sin \theta - 1 } = 5 \tan \theta \quad \sin \theta \neq \frac { 1 } { 2 }$$ can be written in the form $$3 \sin ^ { 3 } \theta + 10 \sin ^ { 2 } \theta - 8 \sin \theta = 0$$ (b) Hence solve, for \(- \frac { \pi } { 4 } < x < \frac { \pi } { 4 }\) $$\frac { 3 \sin 2 x \cos 2 x } { 2 \sin 2 x - 1 } = 5 \tan 2 x$$ giving your answers to 3 decimal places where appropriate.