Save guides, add subjects and pick up where you left off with your BBC account. All quadratic functions have the same type of curved graphs with a line of symmetry. The graph of the quadratic ...

Many former algebra students have painful memories of struggling to memorize the quadratic formula. A new way to derive it, overlooked for 4,000 years, is so simple it eliminates the need.

Before students are presented with the quadratic formula, they’re taught a simpler method to solve certain equations. For simplicity, we’ll consider an equation where a = 1. x ² – 4 x – 5 = 0 ...