Algebrahard · Past Paper
If x + 1/x = 4, find x^2 + 1/x^2.
A16
B14
C18
D12
✓ Correct Answer: B — 14
(x + 1/x)^2 = x^2 + 2 + 1/x^2. So 4^2 = x^2 + 1/x^2 + 2, giving 14.
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