Hi I will just preamble this with - "I have developed a strong hatred for the letter e"

So the integral is integral sign ("S") 3^x/(sqrt(e^2x +1)) dx

so if I let U = e^x then x = ln u (I found this in another solution) then dx = du/u

so S (e^x)/(sqrt (e^2x +1)) dx = S u/sqrt(u^2 +1) (du/u)

= S du/ sqrt (u^2 +1)

= sqrt(u^2 + 1) (2u) + C

=2e^x (sqrt(e^2x + 1) +C

Did I do this correctly?

Thanks

Calculus Beginner