Question

Prove: tan^2xcosx/2secx=1/2sin^2x

Answer 1

\[(\tan ^2 x)(cosx)\div2secx = (1/2)\sin^2x\]

Answer 2

start by using tanx =sinx/cosx
also secx=1/cosx

Answer 3

you should have something like this :
\[\frac{\sin^2 x}{\cos^2 x}\frac{\cos x}{2}cos x=?\]
this after using the identities i mentioned above

Answer 4

it is all clear from there
you should be able to carry it out

Answer 5

just one mention one thing if \[\sec x=\frac{1}{\cos x}\] then \[\cos x=\frac{1}{\sec x}\]
just and inverse relation between cos and sec
i used this if you read my comment above