表达式6: "f" left parenthesis, "x" , right parenthesis equals StartFraction, left parenthesis, "x" squared plus "a" "x" plus "b" , right parenthesis Over 2 "x" minus 8 , EndFractionfx=x2+ax+b2x−8
6
表达式7: left bracket, "f" left parenthesis, 8 , right parenthesis , "f" left parenthesis, 6 , right parenthesis , right bracket tilde left bracket, 0 , 0 , right bracketf8,f6~0,0
