English

If ω is a complex cube root of unity, find the value of (1 + ω)(1 + ω2)(1 + ω4)(1 + ω8)

Advertisements
Advertisements

Question

If ω is a complex cube root of unity, find the value of (1 + ω)(1 + ω2)(1 + ω4)(1 + ω8)

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

(1 + ω)(1 + ω2)(1 + ω4)(1 + ω8)

= (1 + ω)(1 + ω2)(1 + ω)(1 + ω2)  ...[∵ ω3 = 1, ∴ ω4 = ω]

= (– ω2)(– ω)(– ω2)(– ω)

= ω6

= (ω3)2

= (1)2

= 1

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

RELATED QUESTIONS

If `omega` is a complex cube root of unity, show that `(2 - omega)(2 - omega^2)` = 7


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, show that `((a + bomega + comega^2))/("c" + aomega + bomega^2) = omega^2`.


Find the value of ω18


Find the value of ω–30


If ω is a complex cube root of unity, show that (1 + ω)3 − (1 + ω2)3 = 0


If ω is a complex cube root of unity, show that (3 + 3ω + 5ω2)6 − (2 + 6ω + 2ω2)3 = 0


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


If ω is a complex cube root of unity, show that (a + b)2 + (aω + bω2)2 + (aω2 + bω)2 = 6ab


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


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


If , where α and β are the complex cube-roots of unity, show that xyz = a3 + b3.


Find the equation in cartesian coordinates of the locus of z if |z – 3| = 2


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


Find the equation in cartesian coordinates of the locus of z if |z – 2 – 2i| = |z + 2 + 2i|


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


Which of the following is the third root of `(1 + i)/sqrt2`? 


If (1 + ω2)m = (1 + ω4)m and ω is an imaginary cube root of unity, then least positive integral value of m is ______.


Let z = `(1 - isqrt(3))/2`, i = `sqrt(-1)`. Then the value of `21 + (z + 1/z)^3 + (z^2 + 1/z^2) + (z^3 + 1/z^3)^3 + ...... + (z^21 + 1/z^21)^3` is ______.


If 1, α1, α2, ...... αn–1 are the roots of unity, then (1 + α1)(1 + α2) ...... (1 + αn–1) is equal to (when n is even) ______.


The value of the expression 1.(2 – ω) + (2 – ω2) + 2.(3 – ω)(3 – ω2) + ....... + (n – 1)(n – ω)(n – ω2), where ω is an imaginary cube root of unity is ______.


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, then prove the following:

(ω2 + ω − 1)3 = −8


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`


Find the value of `sqrt(-3) xx sqrt(-6)`.


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