11/04/2007, 10:53 PM

Ivars Wrote:Logarithm itself has 2 branches such that log (-1) = +i *pi or - i*pi.

The logarithm has a branch for each integer , that is for you get . This is because the logarithm is the inverse of the exponential and .

So its not really about chosing the sign of but about chosing the .

Quote:h(e^pi/2) = +-i +- 2pik.

Again, this is not true. If we have a fixed point of then (or ) is usually not again a fixed point (and hence not a branch of ).

For example then but also .

PS: the name is sqrt and not sgrt