∴v'(t0)=f"(z0)z"(t0)≠0 Argn (to)=Argf(zo)+ Argz(to) 记Φ Ap Argf(zo)= Argw(to)-Argz'(to) 即a=①-q(1 C:z=(t) r:w=( T W=f(z) 09 w'( t 0 ) = f '( z 0 ) z'( t 0 )  0 '( ) '( ) '( ) 0 0 0  Argw t = Argf z + Argz t 记    '( ) '( ) '( ) 0 0 0 即 Argf z = Argw t − Argz t 即  =  −  (1) C : z = z ( t ) o (z) x y ov ( w ) u  : w = f[z(t)] w= f (z) →  T '  T 0 z w0