Answers>Maths>IB>Article

Finding complex numbers using DeMoivre's Theorem

Find the cube roots of 21/2cis(pi/4)
21/2cis(pi/4+ 2pi k), for every integer k
By DeMoivre:
21/2
1/3cis((pi/4+ 2pi k)/3)321/6cis(pi/12+ 2/3pi *k)
Taking k=0,1,2 gives the three cube roots:z1= 21/6cis(pi/12) (k=0)z2= 21/6cis(3pi/4) (k=1)z3= 21/6cis(17pi/12) (k=2)

Answered by Lisa R. Maths tutor

3105 Views

See similar Maths IB tutors

Related Maths IB answers

All answers ▸

Determine the coefficient of y^3 in the binomial expansion (2x-3y)^4


Find cos4x in terms of cosx.


Find the intersection point/s of the equations x²+7x-3 and 3x+4


Solve the integral int(sin^2(x))dx


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences