Question

Rezultatul calculului (cos 30 grade + sin 30 grade) (cos 60 grade - sin 60 grade)

Answer 1

E= (√3/2 + 1/2) · (1/2 - √3/2) = √3/4 - 3/4 + 1/4 - √3/4 = (-3 +1)/4 = -2/4 = -1/2

Answer 2

$(cos30 \textdegree+sin30 \textdegree)(cos60 \textdegree-sin60 \textdegree)=(\frac{\sqrt3}{2}+\frac{1}{2})(\frac{1}{2}-\frac{\sqrt3}{2})=\frac{\sqrt3+1}{2}*\frac{1-\sqrt3}{2}=\frac{(\sqrt3+1)(1-\sqrt3)}{4}=\frac{\sqrt3-\sqrt3^2+1-\sqrt3}{4}=\frac{-3+1}{4}=\frac{-2}{4}=\frac{-1}{2}$