If x=97+56\sqrt{3}, then what is the value of \sqrt{x}+\frac{1}{\sqrt{x}}?

  1. A. 7
  2. B. 6
  3. C. 5
  4. D. 4

Correct Answer: D. 4

Explanation

Observe that 97+56\sqrt{3} = (7+4\sqrt{3})^2. Taking the square root gives \sqrt{x} = 7+4\sqrt{3}, which further equals (2+\sqrt{3})^2. Thus, \sqrt{x} = 2+\sqrt{3}. Its reciprocal is \frac{1}{2+\sqrt{3}} = 2-\sqrt{3}. Their sum is 2+\sqrt{3} + 2-\sqrt{3} = 4.

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