How do you write an equation for a parabola from a table of values?

Question

loser66 · Answer

The standard form of a parabola is y = ax^2 +bx+c
So that , if you don't know the equation of the parabola, then you need solve for 3 unknowns a, b, c
To do this, you need 3 points on the table, let say (x1, y1), (x2,y2) , (x3, y3)
one by one, you plug them into the standard form. So that you have 3 equations with 3 unknowns a, b, c
Solve for them, 
then plug all a, b, c back to the original standard form to get the equation of the parabola