表达式2: "F" left parenthesis, "x" , "y" , "x" Subscript, 1 , Baseline , "y" Subscript, 1 , Baseline , "x" Subscript, 2 , Baseline , "y" Subscript, 2 , Baseline , right parenthesis equals StartFraction, 1 Over left parenthesis, "x" minus "x" Subscript, 1 , Baseline , right parenthesis squared plus left parenthesis, "y" minus "y" Subscript, 1 , Baseline , right parenthesis squared , EndFraction plus StartFraction, 1 Over left parenthesis, "x" minus "x" Subscript, 2 , Baseline , right parenthesis squared plus left parenthesis, "y" minus "y" Subscript, 2 , Baseline , right parenthesis squared , EndFractionFx,y,x1,y1,x2,y2=1x−x12+y−y12+1x−x22+y−y22
2
表达式3: "F" left parenthesis, "x" , "y" , "a" , "b" , "c" , "d" , right parenthesis greater than 1Fx,y,a,b,c,d>1
