ok this is my lasst question of the night i promise!
Find the unique quadratic function that passes through the points (-2, 5), (1,-1), and (6, 29). use matrices to solve
so we have,
$\displaystyle -1=a+b+c$
$\displaystyle 29=36a+6b+c$
$\displaystyle 5 = 4a-2b+c$
Which can be written in matrix form as
$\displaystyle
\left[ \begin{array}{c}
a\\
b\\
c\end{array}\right]=\left[ \begin{array}{ccc}
1 & 1 & 1 \\
36 & 6 & 1 \\
4 & -2 & 1 \end{array} \right]^{-1} \left[ \begin{array}{c}
-1\\
29\\
5\end{array}\right]
$
Now you need to find the inverse of a $\displaystyle 3\times 3$ matrix, will be tricky