Applying Cauchy's theorem formula on the complex plane

[chota]

Ok so I am asking for some help, please help.

I don't know how to apply the formula given for Cauchy's Theorum, on the complex plane

if anyone can show me a good website with examples on this topic, please tell me.. I am struggling and this is like a cry for help, please help.

thank you

 

[mathwonk]

the applications involve combining the theorem with the usual estimates for the size of an integral, leading to conclusions about the behavior of complex functions of z as z gets larger. any book on complex variable discusses these things as does no doubt any webpage on it.