Theory Ohm's law (phasors): V=IZV=IZV=IZ. In polar form, division subtracts angles: r1(cosθ1+isinθ1)r2(cosθ2+isinθ2)=r1r2(cos(θ1−θ2)+isin(θ1−θ2))\frac{r_1(\cos\theta_1+i\sin\theta_1)}{r_2(\cos\theta_2+i\sin\theta_2)} =\frac{r_1}{r_2}\left(\cos(\theta_1-\theta_2)+i\sin(\theta_1-\theta_2)\right)r2(cosθ2+isinθ2)r1(cosθ1+isinθ1)=r2r1(cos(θ1−θ2)+isin(θ1−θ2))