√2sin(x+π/4)=2msin(x+π/4)=√2m0到π之间(闭区间)π/4<=x+π/4<=5π/4-√2/2<=sin(x+π/4)<=1,即-√2/2<=√2m<=1所以,-1/2<=m<=√2/2画一个sin的图(注意取值范围,π/4<=x+π/4<=5π/4)所以要有相异两实根只能是π/4<=x+π/4<=3π/4时√2/2<=√2m<11/2<=m<√2/2所以,1/2<=m<√2/2
方程式左方根号下么