(April 29, 2018 at 9:00 am)polymath257 Wrote: But now,
sec(x) = csc (pi/2 - x), so we can do a substitution to find that the integral of sec x is
- ln( tan ( pi/4 - x/2 ) ) +C
A challenge: show this is the same as the 'usual' anti-derivative for sec x.
I think I just did it. I did have to consult the more complex trig identities, though (I don't have time for now to derive them for myself).
Feel free to check my work (note it's rather confusing in terms of the flow, so do rely on your intuition skills to figure out the flow):
https://pasteboard.co/Hj12NGv.png
