find all the roots to the equation: z^3 = 1 + i in polar form

1st write 1+ i in polar form, sketch a diagram to find the angle ( =pi/4) and find the modulus ( sqrt(2))z^3 = Sqrt(2) E^ipi/4This is true for all equivalent solutions (add 2kpi) z^3 = sqrt(2)e^(pi/4 +2kpi)iUse De moivres theorem: z = 2^(1/6) e^(pi/12 +2kpi/3)iThis is an algebraic equation, so has 3 solutions (since z^3 is the highest power) answers are usually given with angles in range -pi < x < pi. So our solutions correspond to k = 0, 1, -1z = 2^1/6 e^ipi/12 , 2^1/6 e^i3pi/4 , 2^1/6 e^-i7pi/12

RM
Answered by Rajan M. Further Mathematics tutor

9934 Views

See similar Further Mathematics A Level tutors

Related Further Mathematics A Level answers

All answers ▸

It is given that z = 3i(7-i)(i+1). Show that z can be written in the form 24i - k. State the integer k.


Find the root of the complex 3+4i


How do I know which substitution to use if I am integrating by substitution?


Why does matrix multiplication seem so unintuitive and weird?!


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:

© 2025 by IXL Learning