15 下列選項何者正確，其中： (A)sin(3− 4i) = sin(3)cos(4) − isin(4)cos(3) (B)sin(3 − 4i) = isin(3) cos(4) − sin(4) cos(3) (C)sin(3− 4i) = sin(3) cosh(4) − isinh(4) cos(3) (D)sin(3− 4i) = isin(3) cosh(4) − sinh(4) cos(3)