What does sin(z with a hat) mean?

[laura_a]

Homework Statement

Sorry for the non-technical term, but I need to use cauchy-riemann equations on sin(z hat) and cos(z hat) to prove they're not analytic... which I'm sure I could try if I knew what it mean... I know for elementary maths that it means conjugate... but I can't find anywhere in my textbook which one to conj? If that's even what it is...

Homework Equations

sin(z) = [e^(iz) - e^(-iz) ] /2i

The Attempt at a Solution

so if that's the equation they want me to differentiate for C-R eqns then what is it's "hat" :) ...

 

[Dick]

"hat" of a+bi is a-bi. It's the complex conjugate, as you said.