y=f(x)=x²-2x+3=(x-1)²+2,开口向上,对称轴x=11,当t≥1时,f(x)max=f(t+1)=t²+2,f(x)min=f(t)=t²-2t+3；2,当t+1≤1,即t≤0时,f(x)max=f(t)=t²-2t+3,f(x)min=f(t+1)=t²+2；3,当0...