The Quadratic Formula
A quadratic equation is an equation of the form ax² + bx + c = 0, where a
. we can solve equations of this form by identifying a, b and c and substituting them into the formula
to find
.
Example: Solve
Then
or
It is very important to get the correct values of
,
, and
. For the following equations the values are given
Notice that if a minus sign appears in the formula we have to solve then that value of, or will be negative.
Then for the first equation
We may also solve quadratic equations by sketching a quadratic graph or by completing the square.
Example:Solve
Then
or 