> Everyone solves quadratics by (a) eyeballing either zero, or (b) \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}. It just doesn't make any sense to use any other method wh

> Everyone solves quadratics by (a) eyeballing either zero, or (b) \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}. It just doesn't make any sense to use any other method when the standard formula is simple arithmetic you can do in your head. You have to remember the formula. I'm a maths student, but I can never remember it (and I also hate to memorize stuff). I remember the shape of it so that I could generally recognise it, but that's about it. I I need the general form, it's easy (for someone with practice) to rederive it from scratch. In practice, when given a quadratic equation, I can either guess its roots fairly quickly or I use completing the square. There are probably some other tricks, such as the one from the article, I could use and others undoubtedly use, but my method works for me, and it's not like I need to solve quadratic equations all the time.