Question

Find the value of this erxpression​

Answer 1

QUESTION :-

$\frac{tan {}^{2} 15° - 1}{tan {}^{2} 15° + 1}$

ANSWER:-

$\frac{tan {}^{2} 15° - 1}{tan {}^{2} 15° + 1} \\ \\ \implies \: \frac{ \frac{1 - sin {}^{2} 15°}{cos°15° \: } \: }{ \frac{1 + sin {}^{2} 15°}{cos°15° \: } } \\ \implies \: \frac{cos {}^{2} \: 15° - sin {}^{2} 15°}{cos {}^{2} \: 15° + sin {}^{2} 15°} \\ \implies \: \frac{cos(2 \times 15)° }{1} \\ \implies cos \: 30° \: \\ \implies \: \red{cos \: 30° = \frac{ \sqrt{3} }{2}}$

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Answer 2

hope this answer is helpful