Right isn't so much a question as an 'am i doing this right'.

Evaluate where is the circle with centre 0 and radius 2, traversed in the usual anti-clockwise sense.

And my answer...

The function is holomorphic on the complex plane except at z=1.

So, using Cauchys integral formula we get with .

Hence, .

This right?

If so, how come the answer doesnt depend on ? Does it not matter what the radius of the circle is?