Quadratic formula - Corbettmaths corbettmaths منتشر شده در تاریخ 1392/02/03 Corbettmaths - This video shows how to use the quadratic formula to solve a quadratic. ... Corbettmaths - This video shows how to use the quadratic formula to solve a quadratic. همه توضیحات ... #education #corbettmaths #corbett #maths