z is a complex number; z = x+iy
z-bar is a complex conjugate; z-bar = x-iy
need to show: sin(z-bar) is not differentiable everywhere
formulas (if needed):
$\displaystyle 1) sinz = (e^(iz) - e^(-iz))/2i$
2) Cauchy Riemann equations
$\displaystyle f = u(x,y) + iv(x,y)$
$\displaystyle u_x = vy; u_y = -v_x$
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problem is i dunno how to express sin(z) as real u(x,y) + iv(x,y). I'm not even sure if C-R is the best way to go about solving this problem.