Question

verify: tanxcos(2x)=sin(2x)-tanx

Answer 1

HINT: \(\tan(x) = \frac{ \sin(x) }{ \cos(x) }\) and \(\cos(2x)= 2\cos(x)-1\) or \(\cos(2x)= \cos^2(x)-\sin^2(x)\)

Answer 2

also: \(\cos(2x)=1-2\sin^2(x)\)

Answer 3

error on the first part, i meant: \(\cos(2x) = 2\cos^2(x)-1\)

Answer 4

\[\tan x \times \cos 2x = \left( \sin x / \cos x \right) \times (2(\cos x)^{2} -1)\]
\[= 2*Cos x *\sin x - \tan x = \sin (2x) - tanx\]

Answer 5

thanks guys ive literaly been working on that problem for an hour.