Quadratic equations
A quadratic equation is any equation that can be put into the following general form:
$ax^2+bx+c=0$
The requirement is that $a \ne 0$. $a$, $b$ and $c$ are coefficients.
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Note
A quadratic equation can have either one, two or no solutions.
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Remember
The equation $x^2+px+q=0$ is called the canonical form of the quadratic equation. It is possible to put every quadratic equation in the canonical form.
To bring a quadratic equation into canonical form, the whole equation is divided by the coefficient $a$ (the number that precedes $x^2$).
$ax^2+bx+c=0$ $|:a$
$x^2+\frac{b}{a}x+\frac{c}{a}=0$
$x^2+\frac{b}{a}x+\frac{c}{a}=0$
Example
Put the equation $2x^2+8x+7=0$ in the canonical form.
$2x^2+8x+7=0$ $|:2$$x^2+4x+3.5=0$