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)

LR
Answered by Lisa R. Maths tutor

3117 Views

See similar Maths IB tutors

Related Maths IB answers

All answers ▸

If f(x)=(x^3−2x)^5 , find f'(x).


How to prove that Integral S 1/(a^2+x^2) dx= 1/a arctan(x/a) + C ?


Solve equation 5^(2*x) = 5^(x)+5


log8(5) = b. Express log4(10) in terms of b


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