# Discriminant

The formula $x = \dfrac{-b \pm \sqrt{b^2-4ac}}{2a}$ gives the solutions to the general quadratic equation $ax^2+bx+c=0$. By examining the expression under the square root sign, $b^2-4ac$, we known as the discriminant, symbol used is $\Delta$. The quadratic formula becomes $x=\dfrac{-b + \sqrt{\Delta}}{2a}$ and $x=\dfrac{-b – \sqrt{\Delta}}{2a}$. $\Delta <0$ If $x^2+2x+3=0$, then $a=1,b=2$ and $c=3$. \( […]