сos33=cos(90-57)=sin57
cos123=cos(180-57)= -cos57
20 20 20 20
= ===5
cos²33+3+cos²123 sin²57+3+cos²57 3+1 4
сos33=cos(90-57)=sin57
cos123=cos(180-57)= -cos57
20 20 20 20
= ===5
cos²33+3+cos²123 sin²57+3+cos²57 3+1 4