C1 Topic 2: Algebra
Solving quadratic equations by using the formula
The display below shows how this is done. You can change the quadratic function and then see the process, step by step.

Summary When solving the quadratic equation ax2+bx+c = 0 , this formula is very useful: \displaystyle \frac{-b \pm \sqrt{b^2-4ac}}{2a}. The formula will normally give two values, though there may only be one, and occasionally no values at all. This depends on the value of b^2-4ac which is known as the "discriminant". Because no calculating aids are allowed in C1, problems requiring roots of quadratics will either involve integer values, or else answers to be given in surd form as above. This page uses jsMath. Note that you can get a better display of the maths by downloading special TeX fonts from jsMath. In the meantime, we will do the best we can with the fonts you have, but it may not be pretty and some equations may not be rendered correctly.