表达式2: "y" equals left parenthesis, "x" minus 1 , right parenthesis natural log left parenthesis, "x" plus 1 , right parenthesisy=x−1lnx+1
2
表达式3: "f" left parenthesis, "x" , right parenthesis equals "x" natural log left parenthesis, "x" , right parenthesis minus left parenthesis, "x" minus 1 , right parenthesis natural log left parenthesis, "x" plus 1 , right parenthesisfx=xlnx−x−1lnx+1