MHT CET202620 April 2026Morning ShiftMathematicsComplex NumberActual
If w is a complex cube root of unity , then the value of w¹⁰ - w^7 + w^5 - w^2 + 1 is.
Options
- A0
- B-1
- C1
- Dw
Correct answer
C. 1
Step-by-step solution
Since w is a complex cube root of unity, w^3 = 1 and 1 + w + w^2 = 0 . Simplifying each term using w^3 = 1 : w¹⁰ = (w^3)^3 w = 1 w = w w^7 = (w^3)^2 w = 1 w = w w^5 = w^3 w^2 = 1 w^2 = w^2 Substituting these values into the given expression: w¹⁰ - w^7 + w^5 - w^2 + 1 = w - w + w^2 - w^2 + 1 = 0 + 0 + 1 = 1 Answer: 1