When adding sinusoidal expressions like 4 sin (3.14t + 20°) and 5 sin (3.14t 70°), electrical engineers sometimes use phasors, which are vectors in polar form.
a. The phasors for these two expressions are written as 420° and 570°. Find the rectangular forms of these vectors.
b. Add the two vectors you found in part a.
c. Write the sum of the two vectors in phasor notation.
d. Write the sinusoidal expression corresponding to the phasor in part c.