Question

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

Answer 1

`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`