Originally Posted by

**elbarto** Hi,

I was hoping to get some advice on the best way to handle this problem. When fitting a quadratic with 3 points, I use a matrix approach to evaluate the coefficients which works nicely. In this case, I have only 2 points but an extra condition. I tried to evaluate the coefficients by simultaneous equations but this was painfully slow and I did not get the right equation.

The conditions are:

$\displaystyle \begin{matrix}

x=0 & y=0 \\

x=12 & y=70 \\

\frac{dy}{dx}=0 & y=-70 \\

\end{matrix}

$

My answer is:

$\displaystyle

y=2.1012x^2 -19.3805x

$

Which satisfies the first 2 conditions but not the third. Any advice on the easiest way to go about this would be greatly appreciated.

Regards Elbarto