Question

36/sin^2 43°+4+sin^2 133°

Answer 1

$frac{36}{sin^{2}43 + 4 + sin^{2}133} =  frac{36}{sin^{2}(30 + 13) + sin^{2}(120 + 13) + 4} =  frac{36}{frac{(sqrt{3}}{2}sin13 + frac{1}{2}cos13)^2 + (frac{(sqrt{3}}{2}cos13 - frac{1}{2}sin13)^2 + 4} = frac{36}{sin^{2}13 + cos^{2}13 + 4} =  frac{36}{5}$