y=x^2-4x+3=x²-4x+4-1=(x-2)²-1≥-1∴函数的最小值y=-12.y=0代入y=x^2-4x+3得 x²-4x+3=0(x-1)(x-3)=0x1=1,x2=3∴函数图象与X轴交点坐标(1,0),(3,0)3.x²-4x+3＞0(x-1)(x-3)＞0∴x＜1或x＞3时,y＞...