the.com/quadratic formula

means A formula that finds the values of x solving any quadratic equation ax²+bx+c=0, using x = (-b ± √(b²-4ac)) / 2a.

from 'Quadratic' comes from Latin quadratus, 'made square,' from quadrare 'to square' — rooted in quattuor, 'four,' because squaring a number's side relates to four-sided figures. The algebra itself is older than the word: Babylonian scribes were solving square-related equations with geometric methods nearly 4,000 years ago, and later Islamic mathematicians, notably al-Khwarizmi (whose name gave us 'algorithm'), systematized the method and the reasoning behind completing the square. The tidy symbolic formula with the ± sign that gets memorized in classrooms today is a much later European algebraic distillation of that long inherited technique, not a single inventor's sudden spell.