Question

15. Let z = 1+ ai be a complex number, a > 0 such that z3 is a real number. Then the sum 1 + 2 + z2 + ... +z11
equal to
(a) -12503i (b) 1250V3i
(c)-136573i (d) 1365v3i​

Answer 1

Answer:

(a) -12503i

the number is add so answer is (a）