[tex]ax^2+bx+c=0 \\ \\ \Delta =b ^2-4ac \\ \\\If \ \Delta >0, \ the \ roots \ are \ unequal \ and \ there \ are \ two \ further \ possibilities.\\\\x_{1}=\frac{-b-\sqrt{\Delta} }{2a} \\\\x_{2}=\frac{-b+\sqrt{\Delta} }{2a}[/tex]
[tex]If \ \Delta =0, \ the \ roots \ are \ equal \ and \ we \ can \ say \ that \ there \ is \ only \ one \ root.\\\\ x_{o}=\frac{-b}{2a} \\\\ If \ \Delta <0, \ then \ roots \ are \ imaginary \ (non-real) \ and \ beyond \ the \ scope \ of \ this \ book.[/tex]