Flag Algebra> complex numbers...
question mark

can you plz give idea abt the concept of cube roots of unity

ashna joy , 15 Years ago
Grade
anser 2 Answers
kawaljeet kumar

consider:

           i^m/n  has n number of roots 

so  z = 1^1/3 has 3 roots.

It can also be written as        z^3 - 1 =0 this is a cubic equation just as a quadratic one so roots of this cubic quation gives

the cube roots of unity.

    1 = cos0 + isin0 =cos2k(pie) + isin2k(pie) 

   1^1/3 =e^i2kpie/3                where k = 0, 1, 2 

 

so roots are :-   1,  e^i2pie/3, e^i4pie/3

 

Last Activity: 15 Years ago
Manash nath

let z be a cube root of 1

=>z3 =1

=>z3 -1 =0

=>(z-1)(z2+z+1) =0

=>z=1 or z2+z+1=0

so the cube roots of unity are 1 and two conjugate complex nos.

Last Activity: 15 Years ago
star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments