antiderivative....short question?

Question

if dy/dx = sec x then y=?

Answer 1

Short answer :
y = ln (sec x + tan x) + C
or
y = ln tan(x/2 + π/4) + C
Choose whichever one works best for you.

Answer 2

Falzoon's answer is quite right. To work it out
multiply sec x by (sec x + tan x)/(sec x + tan x).
Now notice that the numerator is the derivative
of the denominator. Carry on from here!