Найдите 16/cos^2 37+1+cos^2 53

[latex] \frac{16}{cos^237+1+cos^253} =[\; cosa=sin(90-a)\; ]= \frac{16}{sin^2(90-37)+1+cos^253} =\\\\= \frac{16}{\underbrace {sin^253+cos^253}_{1}+1} = \frac{16}{1+1} = \frac{16}{2}=8 [/latex]