ABSTRACT
Quadratic Equation: Ax2+Bx+C=0 has a general solution:

x1= -(B+SQRT((B)2 - 4AC))/2A;
x2= -(B-SQRT((B)2 - 4AC))/2A;

where both roots could be Real or Imaginary. If A=0 quadratic equation itransorms to the linear.

Usage Tips

1). If Text box A is empty, system will automatically assign number 1 to A, so the Equation will become the equivalent of x2+Bx+C=0.

2). If Text box B is empty, system will assign 0 to B, so the Equation will become equivalent to Ax2+C=0.

3). If Text box C is empty, system will assign 0 to C, so the Equation will become equivalent to Ax2+Bx = 0.

4). Equation Ax2-Bx+C=0 is equivalent to Ax2+(-B)x+C=0, so in order to solve this equation negative -B could be entered in a Text Box. The alternative way is to use DropDowns, which allow to select either "+" or "-" signs between the terms.