The GATE Grind

GATE 2026 BM – Question 27

Signals and Systems · Laplace and Fourier Transforms · 1 mark · Multiple choice

x[n] is real and odd. Which describes its DTFT $X(e^{j\omega})$?

  1. Real and even
  2. Imaginary and even
  3. Real and odd
  4. Imaginary and odd

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: (D) Imaginary and odd

Explanation

In the Fourier sum, the cosine terms cancel between n and −n because x is odd, while sine terms add. Therefore only an imaginary component remains. Its sine dependence is odd in frequency, so the DTFT is imaginary and odd, D.

More Laplace and Fourier Transforms questions

All Laplace and Fourier Transforms questions →