1. The form of a quadratic function of one variable
2. Graphs and properties of quadratic functions of one variable
The image of a quadratic function is a parabola. The fixed-point formula of the image is (-b/2a, 4ac-b*b/4a), and the symmetry axis straight line x=-b/2a.
3. Mokune formula
For a quadratic equation of the form ax*x+b*x+c=0, its root formula is:
4. Vedic Theorem
If x1 and x2 are the two roots of the equation ax*x+b*x+c=0, then
x1+x2=-b/a,
x1*x2=c/a,
|x1-x2|=△/|a|