English

If ω is a complex cube root of unity, show that (a − b) (a − bω) (a − bω2) = a3 − b3

Advertisements
Advertisements

Question

If ω is a complex cube root of unity, show that (a − b) (a − bω) (a − bω2) = a3 − b3

Sum
Advertisements

Solution

ω is the complex cube root of unity

∴ ω3 = 1 and 1 + ω + ω2 = 0

Also, 1 + ω2 = − ω, 1 + ω = − ω2 and ω + ω2 = − 1

L.H.S. = (a − b)(a − bω)(a − bω2)

= (a − b) (a2 − abω2 − abω + b2ω3)

= (a − b) [a2 − ab(ω2 + ω) + b2(1)]

= (a − b) [a2 − ab(−1) + b2]

= (a − b) (a2 + ab + b2)

= a3 − b3

= R.H.S.

shaalaa.com
  Is there an error in this question or solution?
Chapter 1: Complex Numbers - Exercise 1.4 [Page 20]

RELATED QUESTIONS

If ω is a complex cube root of unity, show that (2 + ω + ω2)3 - (1 - 3ω + ω2)3 = 65


If ω is a complex cube root of unity, find the value of (1 + ω2)3


If `omega` is a complex cube root of unity, find the value of `(1 + omega)(1 + omega^2)(1 + omega^4)(1 + omega^8)`


If α and β are the complex cube roots of unity, show that α2 + β2 + αβ = 0.


If ω is a complex cube root of unity, then prove the following: (ω2 + ω - 1)3 = – 8


If ω is a complex cube root of unity, then prove the following:  (a + b) + (aω + bω2) + (aω2 + bω) = 0.


Find the value of ω21


Find the value of ω–105


If ω is a complex cube root of unity, show that (1 + ω − ω2)6 = 64


If ω is a complex cube root of unity, find the value of `ω + 1/ω`


If α and β are the complex cube root of unity, show that α2 + β2 + αβ = 0


If α and β are the complex cube root of unity, show that α4 + β4 + α−1β−1 = 0


Find the equation in cartesian coordinates of the locus of z if |z| = 10


Find the equation in cartesian coordinates of the locus of z if |z + 8| = |z – 4|


If ω(≠1) is a cube root of unity and (1 + ω)7 = A + Bω, then A and B are respectively the numbers ______.


If α and β are complex cube roots of unity, prove that (1 − α)(1 − β) (1 − α2)(1 − β2) = 9.


If ω is the cube root of unity then find the value of `((-1 + "i"sqrt(3))/2)^18 + ((-1 - "i"sqrt(3))/2)^18`


Let α be a root of the equation 1 + x2 + x4 = 0. Then the value of α1011 + α2022 – α3033 is equal to ______.


Simplify the following and express in the form a + ib.

`(3i^5 + 2i^7 + i^9)/(i^6 + 2i^8 + 3i^18)`


If w is a complex cube root of unity, show that `((a+bw+cw^2))/(c+aw+bw^2) = w^2`


If w is a complex cube root of unity, show that `((a + bw + cw^2))/(c+aw+bw^2) = w^2`


If w is a complex cube root of unity, show that `((a+bw+cw^2))/(c+aw+bw^2) =w^2`


If w is a complex cube root of unity, show that `((a + bω + cω^2))/(c + aω + bω^2) = ω^2`


If w is a complex cube root of unity, show that `((a+bw+cw^2))/(c+aw+bw^2) = w^2`


If w is a complex cube root of unity, show that `((a + bw + cw^2))/(c + aw + bw^2) = w^2`


If w is a complex cube root of unity, show that `((a+bw+cw^2))/(c+aw+bw^2)=w^2`


If w is a complex cube-root of unity, then prove the following. 

(w2 + w - 1)3 = - 8


If w is a complex cube root of unity, show that `((a + bomega + comega^2))/(c + aomega + bomega^2) = w^2`


If ω is a complex cube-root of unity, then prove the following.

(ω2 + ω − 1)3 = −8


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×