Question

5/ cos^2 27(градусов) + cos^2 117(градусов)

Answer 1

$frac{5}{ cos^{2}27 ^{0} + cos^{2} 117^{0} } = frac{5}{ cos^{2} 27 ^{0} +(cos(90 ^{0}+27 ^{0} )) ^{2} } = frac{5}{ cos^{2} 27^{0}+(-sin 27^{0} ) ^{2} } =$
$=frac{5}{ cos^{2} 27^{0}+sinx^{2} 27^{0} } = frac{5}{1} =5$