1)
-2cos(90°-α)-2cos(α+270°)+3cos(α+450°)=
=-2sinα-2sinα+3cos(360°+(90°+α))=
=-4sinα+3cos(90°+α)=
=-4sinα-3sinα= -7sinα= -7*(-0.2)=1,4
Ответ: 1,4
2)
-ctg(α+90°)+4ctg(α+270°)-3tg(α+360°)=
=tgα-4tgα-3tgα= -6tgα= -6*0.65= -3.9
Ответ: -3,9
3)
cos(5π/2 -α)-4sin(π-α)+3sin(3π-α)=
=cos(2π+(π/2 - α))-4sinα+3sin(2π+(π-α))=
=cos(π/2 - α)-4sinα+3sin(π-α)=
=sinα-4sinα+3sinα=0
Ответ: 0