答案为C1、将i1、i2统一为余弦函数：i1(t)=Imcos(t+π/4)i1(t)=Imsin(t-π/2)=Imcos(t-π/2-π/2)=Imcos(t-π)2、写成相量形式：I1=I∠π/4I2=I∠-π3、相位差为：π/4-π=-3π/4说明i1滞后i2，角度为3π/4
