表达式5: negative StartRoot, "x" squared plus "y" squared , EndRoot equals "f" left parenthesis, tan to the negative 1st power left parenthesis, StartFraction, "y" Over "x" , EndFraction , right parenthesis minus StartFraction, "w" Over "v" , EndFraction StartRoot, "x" squared plus "y" squared , EndRoot sin left parenthesis, tan to the negative 1st power left parenthesis, StartFraction, "y" Over "x" , EndFraction , right parenthesis , right parenthesis , right parenthesis left brace, "x" less than 0 , right brace left brace, "y" less than "t" , right brace−x2+y2=ftan−1yx−wvx2+y2sintan−1yxx<0y<t
