Q.If \(\frac{x}{y} = \frac{a + 2}{a - 2}\), then find the value of \(\frac{x^2 - y^2}{x^2 + y^2}\).

\(\frac{x}{y} = \frac{a + 2}{a - 2}\) So, \(\frac{x^2}{y^2} = \frac{(a + 2)^2}{(a - 2)^2}\) [By squaring both sides] Then, \(\frac{x^2}{y^2} = \frac{a^2 + 4a + 4}{a^2 - 4a + 4}\) Now, \(\frac{x^2 + y^2}{x^2 - y^2} = \frac{(a^2 + 4a + 4) + (a^2 - 4a + 4)}{(a^2 + 4a + 4) - (a^2 - 4a + 4)}\) [Using addition and subtraction] So, \(\frac{x^2 + y^2}{x^2 - y^2} = \frac{a^2 + 4a + 4 + a^2 - 4a + 4}{a^2 + 4a + 4 - a^2 + 4a - 4}\) \(\frac{x^2 + y^2}{x^2 - y^2} = \frac{2(a^2 + 4)}{8a}\) \(\frac{x^2 + y^2}{x^2 - y^2} = \frac{a^2 + 4}{4a}\) (Answer)
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