Complex Analysis: Lecture 4: more on square root and trig and hyperbolics

Here I spend another half hour trying to explain the idea of a branch cut, and a bit about the idea of a Riemann surface. Then in the last 20 minutes we look at the cosine, sine and their hyperbolic versions in the complex domain. Hopefully I show enough for you to work problems involving these. We derive a nice formula for the modulus of cos(z) and we show the pythagorean identity holds in the complex domain.

[georgesadler]

Professor Cook, thank you for a beautiful lecture on square root, trigonometry, hyperbolics sine and cosine function.

[ComputerNerd]

might wanna make a correction at 41:00 you forgot the i in the definition of exp(z)

[parthapratimmanna]

The video is good...but think b4 U speak....I m proud to be an Indian....respect our nation...