• Nov 8th 2008, 07:21 AM
petit_chou
I'm attempting to help my son with the following - any assistance offered would be greatly appreciated!

Write a quadratic in standard form for the parabola that passes through the given points:

(-4, -3), (0, -2), (1,7)

My son is lost as to how to tackle this - any suggestions? (Worried)
• Nov 8th 2008, 07:40 AM
skeeter
standard form ...

\$\displaystyle y = ax^2 + bx + c\$

you have three points, substitute in the corresponding x and y values to create three equations ...

\$\displaystyle -3 = a(-4)^2 + b(-4) + c\$

\$\displaystyle -2 = a(0)^2 + b(0) + c\$

\$\displaystyle 7 = a(1)^2 + b(1) + c\$

note that the second equation basically gives you the value of the constant coefficient "\$\displaystyle c\$".

using \$\displaystyle c = -2\$ and the other two equations, solve for the quadratic coefficient "a" and the linear coefficient "b".
• Nov 8th 2008, 07:53 AM
petit_chou
Skeeter,

Thank you SO much for your rapid reply. You're a life saver!!

(Rofl)