من المعادلة:
begin mathsize 18px style bold italic x to the power of bold 2 bold space bold space bold space bold minus bold space bold 16 bold space bold equals bold space bold 0 end style
نجد من المعادلة أن قيمة begin mathsize 18px style bold italic a end style ( معامل begin mathsize 18px style bold italic x to the power of bold 2 end style ):
begin mathsize 18px style bold 1 end style
begin mathsize 18px style bold 2 end style
begin mathsize 18px style bold 3 end style
begin mathsize 18px style bold 4 end style