Expression 3: "f" left parenthesis, "x" , right parenthesis equals "x" to the 6th power plus "k" "x" to the 4th power minus 9 "x" squared minus 27fx=x6+kx4−9x2−27
3
Expression 4: "f" left parenthesis, "x" , right parenthesis equals negative 1 half "x" to the 7th power minus 441 "x" cubed plus "k"fx=−12x7−441x3+k