Задача 57750 ...

5ff1d32e960c3c35933d951f

06.02.2021 19:42:05

★

а)a*b=4*5*cos(30^(o))=4*5*[m]\frac{\sqrt{3}}{2}[/m]=20*[m]\frac{\sqrt{3}}{2}[/m]=[m]10\sqrt{3}[/m]
б)a*b=8*7*cos(45^(o))=8*7*[m]\frac{\sqrt{2}}{2}[/m]=56*[m]\frac{\sqrt{2}}{2}[/m]=[m]28\sqrt{2}[/m]
в)a*b=2.4*10*cos(60^(o))=2.4*10*[m]\frac{1}{2}[/m]=24*[m]\frac{1}{2}[/m]=12
г)a*b=0.8*[m]\frac{1}{2}[/m]*cos(40^(o))=0.8*[m]\frac{1}{2}[/m]*0.766=0.4*0.766 ≈ 0.3