Evaluate (1 + i)^12

First convert to mod-arg form in order to use de Moivre's theorem. |1 + i| = (1^2 + 1^2)^1/2 = 2^1/2 arg(z) is the angle made by the vector of the complex number and the positive real axis. I world recommend by always drawing a diagram arg(1+i) = tan^-1(1/1) = tan^-1(1) = π /4Therefor 1+i = 2^1/2(cos(π /4) +isin(π /4))Now use de Maivre's theorem to raise to the power of 12(1+i)^12 = (2^1/2)^12(cos(π /4) + isin(π /4))^12 =2^6(cos(12π /4) + isin(12π /4))= 64 (cos(3π ) + isin(3π )) As 2π is a full rotation is can be equated to zero.= 64(cosπ + isinπ ) = 64(-1)=-64

CL
Answered by Charlie L. Further Mathematics tutor

5043 Views

See similar Further Mathematics A Level tutors

Related Further Mathematics A Level answers

All answers ▸

How would you show the equation f(x) = 2x – 10 sin x – 2 has a root between 2 and 3 (where x is measured in radians)


how do I do proofs by induction?


Solve x^2+8x-5=0 using completing the square


A block of mass 50kg resting on a rough surface with a coefficient of friction equal to 1/3. Find the maximum angle at which the surface can be inclined to the horizontal without the block slipping. Give your answer to 3 significant figures


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2026 by IXL Learning