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GATE 2016 EE (EE2) – Question 39

Engineering Mathematics · Calculus: Mean value theorems, Theorems of integral calculus, Evaluation of definite and improper integrals, Partial derivatives, Multiple integrals, Fourier series · 2 marks · Multiple choice

The value of $2\int_{-\infty}^{\infty}\sin(2\pi t)/(\pi t)\,dt$ is

  1. 0
  2. 0.5
  3. 1
  4. 2

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Correct answer: (D) 2

Explanation

The standard Dirichlet integral is $\int_{-\infty}^{\infty}\sin(at)/t\,dt=\pi$ for a>0, interpreted as the symmetric improper integral.

With a=2π, dividing by π gives one. The prefactor two therefore makes the requested value **2, D**. The removable value at t=0 does not affect the integral.

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