من المعادلة:
bold italic x to the power of bold 2 bold space bold space bold plus bold 8 bold italic x bold plus bold 7 bold equals bold 0
نجد أن قيمة المميز ( begin mathsize 18px style bold italic z bold space bold equals bold space bold italic b to the power of bold 2 bold space bold minus bold space bold 4 bold space bold italic a bold space bold italic c end style ) يساوي:
begin mathsize 14px style bold 36 end style
begin mathsize 14px style bold 84 end style
bold 72
bold 4
