Practice problem
Let x=aeθix = ae^{\theta i}x=aeθi and y=beφiy = be^{\varphi i}y=beφi. What is xyxyxy?
abeθφiab e^{\theta \varphi i}abeθφi
abe−θφab e^{-\theta \varphi}abe−θφ
(a+b)e(θ+φ)i(a+b) e^{(\theta + \varphi) i}(a+b)e(θ+φ)i
(a+b)eθφi(a + b) e^{\theta \varphi i}(a+b)eθφi
abe(θ+φ)iab e^{(\theta + \varphi) i}abe(θ+φ)i
Type a concept, like “slope” or “photosynthesis”.