Question

Which of the following is a third root of the given complex number?
64 (cos(pi/7)+i sin(pi/7))
Check all that apply.
a. 4(cos(12pi/21) + i sin(12pi/21))
b. 64(cos(pi/21)+ i sin(pi/21))
c. 4(cos(15pi/21)+ i sin(15pi/21))
d. 4(cos(pi/21)+ i sin(pi/21))

Answer 1

c and d