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Part CCSIR NET December 2024multiply-by-one-minus-i-to-fix-the-real-part

Multiply by one minus i to fix the real part

For z = x + iy ∈C\in \mathbb{C}, let f(z) = u(x, y) + iv(x, y) be an entire function such that u(x, y) + v(x, y) = 1. Which of the following statements are FALSE?

  1. A.f is a constant function.
  2. B.If f(0)∈Rf(0) \in \mathbb{R}, then f(0) + f(1) = 1.✓ Correct
  3. C.f(C)f(\mathbb{C}) is connected.
  4. D.If f(2)∈Rf(2) \in \mathbb{R}, then f(i) + f(1) = 2.

You have the answer. Trap Analysis is why the other three were written.

Not a worked solution repeated four times — the specific reasoning error each wrong option was built to reward, and why this one tests execution slip.

See pricing

50 are analysed free — try those first.

The trap it tests

Execution slip

The idea was right. The computation was not.

Drill statements like this

Related counterexample: A harmonic function on any domain has a harmonic conjugate

More on this topic

The chapter behind this: Cauchy–Riemann — what they do and do not give you — free to read

From Analytic Functions › Cauchy–Riemann equations, harmonic functions

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