Quadratic form is given in the form
, where a, b, and c are constants
We substitute the value (8, 12) and (5,3) in turn
... Equation 1
... Equation 2
Equation 1 - Equation 2 gives
, we call this Equation 3
We also know that (5, 3) is the turning point of the curve, where the value of
is given by 
Substitute
... Equation 4
Substitute Equation 4 into Equation 3
Now we need to work out the value of
and 
Substitute back into equation 4
Substitute and into either equation 1 or equation 2
Hence the equation of the quadratic curve is
We substitute the value (8, 12) and (5,3) in turn
Equation 1 - Equation 2 gives
We also know that (5, 3) is the turning point of the curve, where the value of
Substitute
Substitute Equation 4 into Equation 3
Now we need to work out the value of
Substitute
Substitute
Hence the equation of the quadratic curve is