Edexcel C12 2015 June — Question 13

Exam BoardEdexcel
ModuleC12 (Core Mathematics 1 & 2)
Year2015
SessionJune
TopicTrig Proofs

  1. (i) Showing each step in your reasoning, prove that
$$( \sin x + \cos x ) ( 1 - \sin x \cos x ) \equiv \sin ^ { 3 } x + \cos ^ { 3 } x$$ (ii) Solve, for \(0 \leqslant \theta < 360 ^ { \circ }\), $$3 \sin \theta = \tan \theta$$ giving your answers in degrees to 1 decimal place, as appropriate.
(Solutions based entirely on graphical or numerical methods are not acceptable.)