π радиан = 180 °
[m]\frac{9π}{4}=\frac{9\cdot 180 ° }{4}=405 ° [/m]
[m]\frac{4π}{5}=\frac{4\cdot 180 ° }{5}=144 ° [/m]
[m]5π=5\cdot 180 ° =900 ° [/m]
3.
a)
cos(π/3)=1/2
tg(π/4)=1
sin(3π/2)=-1
2*(1/2)^2-3*1-1=(1/2)-3-1=[b]-3,5[/b]
б)
5*(1)^2-4*(-1)+3*1=5+4+3=[b]12[/b]
в)
(1/2)-1+0=-(1/2)