三、性质 1.∑CM=∑cJ(M k=1 2.若=1+2+… 则!/=∑ 用积分定义证 3. f(ed:=l,f(e)d=三、性质 1． 1 1 ( ) ( ) n n u k k k l l k k C f z dz C f z dz = = å å= ò ò 2． 若 1 2 n l = l + + l l L 则 1 ( ) ( ) k n l l k f z dz f z dz = ò ò =å 3． ( ) ( ) AB BA l l f z dz = - f z dz ò ò 用积分定义证