Find the Value

Find the value

\[ x = 7 + 4\sqrt{3}, \quad xy = 1 \]

Solution:

\[ y = \frac{1}{x} = 7 – 4\sqrt{3} \]

\[ x + y = (7 + 4\sqrt{3}) + (7 – 4\sqrt{3}) = 14 \]

\[ xy = 1 \]

\[ x^2 + y^2 = (x + y)^2 – 2xy = 14^2 – 2 = 196 – 2 = 194 \]

\[ \frac{1}{x^2} + \frac{1}{y^2} = x^2 + y^2 = 194 \]

\[ \therefore \text{Correct Answer: } 194 \ (\text{Option c}) \]

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