Expression 3: "f" Subscript, 1 , Baseline ( "x" ) equals "x" cubed minus 9 "x"f1(x)=x3−9x
3
Expression 4: "f" Subscript, 1 , Baseline left parenthesis, "x" , right parenthesis plus "f" Subscript, 2 , Baseline left parenthesis, "x" , right parenthesis plus "f" Subscript, 3 , Baseline left parenthesis, "x" , right parenthesisf1x+f2x+f3x