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GATE 2024 MA – Question 37

Complex Analysis · Analytic and Harmonic Functions · 2 marks · Multiple choice

On |z|=1, which function is a uniform limit of polynomials in z?

  1. $\bar z$
  2. $\operatorname{Re}z$
  3. $e^z$
  4. $|z+1|^2$

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Correct answer: (C) $e^z$

Explanation

Taylor polynomials of eᶻ converge uniformly on the closed unit disk, proving **C**. The contour integral of every polynomial around the unit circle is zero, and uniform convergence preserves it. The other choices have nonzero integrals because they contain respectively z⁻¹,(z+z⁻¹)/2, and 2+z+z⁻¹ on the circle.

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