Edexcel Mathematics October 2020 · Paper 2 · Question 10 · ExamRizz

ExamRizzEdexcel MathematicsMathematics

October 2020 · Paper 2 · Question 10 · 8 marks

10. In this question you must show all stages of your working. Solutions r elying entirely on calculator technology are not acceptable. (a) Show that cos 3 A ≡ 4 cos3 A − 3 cos A (4) (b) Hence solve, for −90°  x  180°, the equation 1 − cos 3x = sin2 x (4) 27 28 29

Lesson: Definitions of Sine, Cosine and Tangent and Exact Values