Edexcel AEA 2017 June — Question 2 9 marks

Exam BoardEdexcel
ModuleAEA (Advanced Extension Award)
Year2017
SessionJune
Marks9
PaperDownload PDF ↗
TopicAddition & Double Angle Formulae
TypeShow equation reduces to tan form
DifficultyChallenging +1.8 This AEA question requires non-routine algebraic manipulation to transform tan x into a double angle form, demanding insight to multiply by cos x, apply sin 2x = 2sin x cos x, and recognize √3 relates to 60°. Part (b) then requires solving the resulting equation. The transformation isn't standard textbook fare and requires multiple sophisticated steps with trigonometric identities.
Spec1.05l Double angle formulae: and compound angle formulae1.05o Trigonometric equations: solve in given intervals

2.(a)Show that the equation $$\tan x = \frac { \sqrt { 3 } } { 1 + 4 \cos x }$$ can be written in the form $$\sin 2 x = \sin \left( 60 ^ { \circ } - x \right)$$ (b)Solve,for \(0 < x < 180 ^ { \circ }\) $$\tan x = \frac { \sqrt { 3 } } { 1 + 4 \cos x }$$

2.(a)Show that the equation

$$\tan x = \frac { \sqrt { 3 } } { 1 + 4 \cos x }$$

can be written in the form

$$\sin 2 x = \sin \left( 60 ^ { \circ } - x \right)$$

(b)Solve,for $0 < x < 180 ^ { \circ }$

$$\tan x = \frac { \sqrt { 3 } } { 1 + 4 \cos x }$$

\hfill \mbox{\textit{Edexcel AEA 2017 Q2 [9]}}