O Level Maths Notes: The Quadratic Formula
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
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to find![]()
Example:
Solve
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Then
or
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It is very important to get the correct values of
For
the following equations the values are given
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Notice that if a minus sign appears in the formula we have to
solve then that value of
will
be negative.
Then for the first equation
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We may also solve quadratic equations by sketching a quadratic graph or by completing the square.
Example:Solve![]()
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Then
or
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