Question

Which basic trigonometric identity would you use to verify that tan x cos x =sin x

Answer 1

`\huge\boxed{\tan x=(\sin x)/(\cos x)}`

Explanation:

`\tan x\cos x=\sin x\\\\\tan x=(\sin x)/(\cos x)\\\\\text{Therefore}\\\\\tan x\cos x=(\sin x)/(\cos x)\cdot\cos x\qquad\text{cancel}\ \cos x\\\\\tan x\cos x=\sin x\\\\\text{For}\ x\\eq(\pi)/(2)+k\pi},\ k\in\mathbb{Z}`