Question

Если
$tg2x= \frac{ \sqrt{3} }{2}$
Найдите ответ:
$7 - \frac{2}{cos {}^{2} 2x}$
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Answer 1

$1 + tan^22x = sec^22x => -2sec^22x = -2 - 2tan^22x = -2-2*\frac{3}{4} = -2-1.5=-3.5\\ 7 - 2sec^22x = 7 - 3.5 = 3.5\\Answer: 3.5$