i1=60sin(ωt-30°)
i2=-60cos(ωt-30°) = -60sin(ωt-30°+90°)=-60sin(ωt+60°)=60sin(ωt+60°-180°)=60sin(ωt-120°)
所以 i1 超前i2 90°
8.i1=60sin(ωt-30°),i 2= - 60cos(ωt-30°),..-阿摩線上測驗