Quadratic equations

$a\cdot x^{2}+b\cdot x+c = 0$

Find It is known that:

$D = b^{2}-4\cdot a\cdot c$

Find It is known that:

$x = \frac{-b-\sqrt {D}}{2}$

D - discriminant

Find It is known that:

$x = \frac{-b+\sqrt {D}}{2}$

D - discriminant

Find It is known that:

$a\cdot x^{2}+b\cdot x+c = a\cdot (x-x_1)\cdot (x-x_2)$

x1, x2 - roots of quadratic equation

Find It is known that:

$a\cdot x^{2}+b\cdot x+c = a\cdot (x+\frac{b}{2\cdot a})^{2}+(4\cdot a\cdot c-\frac{b^{2}}{4\cdot a})$

Find It is known that: