Prove that sinxtanx+cosx=secx (where x is theta)?

1 Answer
Oct 4, 2015

tan x = sin x / cos x

Substituting in the above equation we get,

sin x * sin x / cos x + cos x
= sin^2 x / cos x + cos x
= (sin^2 x + cos^2 x) / cos x
Now sin^2 x + cos^2 x = 1 for all values of x
So the above reduces to 1 / cos x which is nothing but sec x