## Jonask 2 years ago $\int \sec x$

proof without using the rationalising by tan x and sec x $\int\sec x=\ln (\tan x +\sec x)+c$

2. Xavier

Try partial fractions. secx=1/cosx=cosx/cos^2(x)=cosx/(1-sin^2(x)) Then do a substitution u=sinx. Do partial fractions the show that the result is the same