- #1
Tangent87
- 148
- 0
In our Complex Methods lecture today, our lecturer went through the example of evaluating the integral [tex]\int_{-1}^1 \frac{(1-x^2)^{1/2}}{x^2+1}dx[/tex] and then proceeded to do the whole contour calculation using the complex function [tex]\frac{(z^2-1)^{1/2}}{z^2+1}[/tex]. I'm concerned that the answer will be a factor of i out because [tex](1-z^2)^{1/2}=i(z^2-1)^{1/2} [/tex] but he said in the lecture it didn't matter, can anyone explain why?