Quadratic Equation Solver Online [Calculator]

Enter Values of Coefficients (ax2 + bx + c = 0)




First Root Value:


Second Root Value:


The formula to solve a quadratic equation is
     -b + √(b2 - 4ac)
 r =  ______________
          2a
Note: We will add the support for complex roots soon.

The term b2 - 4ac is called as discriminant and is of very importance. Depending on the value of discriminant we can tell the nature of the roots of the quadratic equation where a, b and c are the rational numbers.

If value of discriminant (d) is
  • Zero (0) - the equation has real root
  • greater than zero (d > 0) - the equation has real and distinct roots
  • less than zero (d < 0) - the equation has imaginary roots
The discriminant is useful if we want to know the nature of the roots instead of actually calculating them.

If you want C programming language code to find roots of quadratic equation check out this article at C program to find roots of a quadratic equation.