Algebrahard · Past Paper

If the roots of x^2 - kx + 1 = 0 are not real, then k lies in:

A(-2, 2)
B(-∞, -2)
C(2, ∞)
D[-2, 2]

✓ Correct Answer: A(-2, 2)

D < 0 → k^2 - 4 < 0 → k^2 < 4 → -2 < k < 2.

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