now use the substitute
ok
I want to start with integral on the left
first multiply the denominator and numerator with sec(y)+tan(y)
now you have the numerator is the derive of the denominator so the integral is ln(denominator) since the integrate of f'(x)/f(x) is ln(f(x)
this is the first
now
let dv=sec^2y and u=secy
v=tany.....du=secy tany
and the integral in the right we integrate it before