Объяснение:
sin(30°)=1/2
cos(60°)=1/2
sin(45°)=1/√2
sin(30°)*cos(60°)-sin²(45°)=1/2*1/2-(1/√2)²=
=1/4-1/2=-1/4
Объяснение:
sin(30°)=1/2
cos(60°)=1/2
sin(45°)=1/√2
sin(30°)*cos(60°)-sin²(45°)=1/2*1/2-(1/√2)²=
=1/4-1/2=-1/4