What does sin(z with a hat) mean?

1. The problem statement, all variables and given/known data

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 text book which one to conj? If thats even what it is...


2. Relevant equations

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

3. The attempt at a solution


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