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Find the quadratic function that goes through the points ( 0, f(0) ), (deltax, f(deltax) ), ( 2deltax, f(2deltax) ). In other words find the values of a, b, and c such that those points satisify the equation g(x) = ax^2 + bx + c. Hint g(0) = f(0)
Alright, i'm not getting how to do this at all, can anyone lead me in the right direction?
Since 3 non-colinear points uniquely determine a parabola, I think the approach is straightforward. What you are trying to do is find a,b,c:Quote:
Originally Posted by dsheller
y = ax2 + bx + c
given three points (x1,y1), (x2,y2), (x3,y3)
Thus, you have
(1)... y1 = ax12 + bx1 + c
(2)... y2 = ax22 + bx2 + c
(3)... y3 = ax32 + bx3 + c
These are 3 equations in 3 unknowns (a, b, c) and by substitution you can obtain expressions for the unknowns in terms of x1, y1, x2, y2, x3, y3. Hint: the fact that x1 = 0 makes things much easier.
Good luck. :)