Question

Help!

Prove:
1-2sin^2 x/2sinxcosx = cot 2x

Answer 1

\[\frac{ 1-2\sin ^{2} x}{ 2sinxcosx }= \cot 2x\]

Answer 2

well I think you'll find the denominator is

sin(2x) = 2sin(x)cos(x)

and the numerator

\[\cos(2x) = \cos^2(x) - \sin^2(x)\]

see if you can use a trig identity and substitute it to get the numerator...

then it might become obvious.