. we can solve equations of this form by identifying a, b and c and
substituting them into the formula
GCSE Maths Notes: 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
