Question

sin patrat de 30 grade + cos patrat de 45 grade = 3/4

Answer 1

$sin^2 30 \textdegree= (\frac{1}{2})^2 = \frac{1}{4}. \\ cos^2 45 \textdegree = (\frac{ \sqrt{2} }{2})^2= \frac{1}{2}. \\ \\ sin^2 30 \textdegree +cos ^2 45\textdegree = \frac{1}{4}+ \frac{1}{2}= \frac{3}{4}.$