Here first of all convert secx in terms of cosx

∴ We get

⇒

∴ We get

⇒

=

∴ The equation now becomes

⇒

We know

Cos 2x = 2 cos²x - 1

∴ We can write the above equation as

⇒

⇒

⇒ 2 sin x –

(

⇒ 2 sin x – ln|sec x + tan x| + c