Prove that $$$\frac{1-\cos 2 \theta}{1+\cos 2 \theta} \equiv \tan ^{2} \theta$$$. ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................

Mathematics

IGCSE&ALevel

CAIE

Exam No：9709_s21_qp_31 Year：2021 Question No：4(a)

Answer:

Use correct double angle formula or $t$-substitution twice
Obtain $\frac{1-\cos 2 \theta}{1+\cos 2 \theta}=\tan ^{2} \theta$ from correct working