表达式11: "d" left parenthesis, "x" , right parenthesis equals StartRoot, left parenthesis, "x" minus "x" Subscript, 1 , Baseline , right parenthesis squared plus left parenthesis, "f" left parenthesis, "x" , right parenthesis minus "y" Subscript, 1 , Baseline , right parenthesis squared , EndRootdx=x−x12+fx−y12
11
表达式12: left parenthesis, "t" "k" plus left parenthesis, 1 minus "t" , right parenthesis "x" Subscript, 1 , Baseline , "t" "f" left parenthesis, "k" , right parenthesis plus left parenthesis, 1 minus "t" , right parenthesis "y" Subscript, 1 , Baseline , right parenthesistk+1−tx1,tfk+1−ty1
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定义域t最小值：
less than or equal to "t" less than or equal to≤t≤
