If \(x = 3 + 2\sqrt{2}\), what is the value of \(x^2 + \frac{1}{x^2}\)?
A. 32
B. 38
C. 36
D. 34
A. 32
B. 38
C. 36
D. 34
Best answer
Answer: D. 34
Answer: (D) 34
\(\frac{1}{x} = \frac{1}{3 + 2\sqrt{2}} = 3 - 2\sqrt{2}\) (multiply by the conjugate; 9 − 8 = 1).
So \(x + \frac{1}{x} = 6\) and \(x^2 + \frac{1}{x^2} = 36 - 2 = 34\).
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