Quandaries
and Queries 

Hi, My name is Monica and I am a student in college. I was very curious about how to prove that arcsech x = ln[(1 + (1x^{2})^{(1/2)}) / x ] I know that sechy = x which equals 1/coshy = 2/(e^{y} + e^{y}). But i am absolutely clueless after that! I really would like to know ASAP, so if you can help, I would appreciate it! Thanks alot. Monica 

Hi Monica, You are correct that is sech y = x then
Multiply both sides by (e^{y} + e^{y}) to get
Now multiply both sides by e^{y} and the equation becomes
This is a quadratic in e^{y} which you can solve using the general quadratic formula. Penny 

