Edexcel Paper 1 2021 October — Question 10

Exam BoardEdexcel
ModulePaper 1 (Paper 1)
Year2021
SessionOctober
TopicAddition & Double Angle Formulae

  1. In this question you should show all stages of your working.
Solutions relying entirely on calculator technology are not acceptable.
  1. Given that \(1 + \cos 2 \theta + \sin 2 \theta \neq 0\) prove that $$\frac { 1 - \cos 2 \theta + \sin 2 \theta } { 1 + \cos 2 \theta + \sin 2 \theta } \equiv \tan \theta$$
  2. Hence solve, for \(0 < x < 180 ^ { \circ }\) $$\frac { 1 - \cos 4 x + \sin 4 x } { 1 + \cos 4 x + \sin 4 x } = 3 \sin 2 x$$ giving your answers to one decimal place where appropriate.