sinα-2sinβ=0,cosα+2cosβ=2

sinα-2sinβ=0sinα=2sinβ①cosα+2cosβ=2cosα-2=2cosβ②①^2+②^2(sinα)^2+(cosα-2)^2=4(sinβ)^2+4(cosβ)^2(sinα)^2+(cosα)^2-4cosα+4=4(sinβ)^2+4(cosβ)^21-4cosα+4=4cosα=1/4sinα-2sinβ=0③cos...