Y=sinX/(sinX+2)的值域誰能帮我解下啊.自己做到-1

Y=sinX/(sinX+2)的值域誰能帮我解下啊.自己做到-1
Y=sinX/(sinX+2)的值域
誰能帮我解下啊.自己做到-1

Y=sinX/(sinX+2)的值域誰能帮我解下啊.自己做到-1
原式=1/1+2/sinx 所以值域为[-1,0)并上(0,1/3]

Y=sinX/(sinX+2)=1-2/(sinX+2) -1<=sinx<=1 1<=sinX+2<=3 2/3<=2/(SinX+2)<=2/1 1-2/1<=1-2/(sinX+2)<=1-2/3 -1<=y<1/3