4.下列函数在何处可导?何处解析?在可导点处求出其导数.-|||-(1) (z)=x(y)^2+i(x)^2y ;-|||-(2) (z)=(x)^2-iy ;-|||-(3) (z)=(z)^3+2iz ;-|||-(4) (z)=sin xchy+icos xshy ;-|||-(5) (z)=dfrac (1)({z)^2-1} ;-|||-(6) (z)=dfrac (az+b)(cz+d)(cneq 0) .