Transform the following sinusoids to phasors:
(a) – 20 cos(4t + 135°)
(b) 8 sin(20t + 30°)
(c) 20 cos (2t) + 15 sin (2t)

Two voltages v, and v2 appear in series so that their sum is v = v1 + 02. If v1 = 10 cos(50t – T/3) V and v2 = 12 cos(50t + 30°) V, find v.