设f（x）=x+2,x≤1.x²,-1＜x＜2.2x,x≥2若f（x）=3,则x=_______

设f（x）=x+2,x≤1.x²,-1＜x＜2.2x,x≥2若f（x）=3,则x=_______
设f（x）=x+2,x≤1.x²,-1＜x＜2.2x,x≥2
若f（x）=3,则x=_______

设f（x）=x+2,x≤1.x²,-1＜x＜2.2x,x≥2若f（x）=3,则x=_______
当x≤1
x+2=3
x=1
当-1＜x＜2
x^2=3
x=√3
当x≥2
2x=3
x=3/2（舍去）
所以x=1,√3

x=1或x=根下3