Сравните a) sin60° и tg(-45°) б) cos60° и cos60°×ctg30° в) sin30° и sin^2_30°

А)sin60° и tg(-45°)
sin60°= $\frac{ \sqrt{3} }{2}$
tg(-45°)= tg135°=-1
sin60° > tg(-45°)
б) cos60° и cos60°×ctg30°
cos60°= $\frac{1}{2}$
cos60°×ctg30°= $\frac{1}{2}$ * $\sqrt{3}$ = $\frac{ \sqrt{3} }{2}$
cos60° < cos60°×ctg30°
в) sin30° и sin²30°
sin30°= $\frac{1}{2}$
sin²30°=sin30°*sin30°= $\frac{1}{2}$ * $\frac{1}{2}$ = $\frac{1}{4}$
sin30° > sin²30°