A quadratic equation is an equation of the form
where 
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
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 ofwill 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 