Locus of z when (z - a)/(z - b) is purely real or purely imaginary
This type of question, asked 5 times: 2021 Paper 20, 2021 Paper 23, 10 Apr 2023, 9 Apr 2024, 7 Apr 2025. All 6 questions below, oldest first.
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Question 1
2021 Paper 20
67
If S={z∈C:z+2iz−i∈R}, then:
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Question 2
2021 Paper 23
74
If z is a complex number such that z−1z−i is purely imaginary, then the minimum value of ∣z−(3+3i)∣ is :
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Question 3
10 Apr 2023
67
Let the complex number z=x+ iy be such that 2z+i2z−3i is purely imaginary. If x+y2=0, then y4+y2−y is equal to:
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Question 4
10 Apr 2023
168
Let S={z=x+iy:4z+2i2z−3i is a real number }. Then which of the following is NOT correct?
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Question 5
9 Apr 2024
154
Let z be a complex number such that the real part of z+2iz−2i is zero. Then, the maximum value of ∣z−(6+8i)∣ is equal to:
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Question 6
7 Apr 2025
61
Among the statements (S1): The set {z∈C−{−i}:∣z∣=1 and z+iz−i is purely real} contains exactly two elements, and (S2): The set {z∈C−{−1}:∣z∣=1 and z+1z−1 is purely imaginary} contains infinitely many elements.