prove:
sin*2x+tan*2x+cos*2x=sec*2x
I have to assume that your * symbols indicate following exponents. We here and in most places with limited typing options usually use a ^ symbol before exponents.
So let us write
sin^2x +tan^2x +cos^2x = sec^2x
That simplifies to
1 + tan^2 x = sec^2 x
Get a common denominator on the left side
(cos^2x + sin^2x)/cos^2x = sec^2 x
1/cos^2x = sec^2 x
sec^2 x = sec^2 x
q.e.d.