f(x)=(x-2)^2-8 开口向上,对称轴是x=2.所以f(x)在区间（2,正无穷）单调递增,在区间（负无穷,2）单调递减 1.当t属于[1,2],g(t)=f(2)=-82.当t属于(负无穷,1),g(t)=f(t+1)=(t+1)^2-4(t+1)-4=t^2-2t-73.当...