Cubic Function Curve Equation. If you plug the coordinates of each of the given points into the generic cubic equation A x 2 B x 2 C x D y you will end up with a system of linear equations in the coefficients of this cubic. Consider the cubic equation f x x8 x10 x20 x 3 38x 2 440x 1600 0.
I presume that you know how to solve such a system of equations. And the coefficients a b c and d are real numbers and the variable x takes real values. Here are some examples of cubic equations.
Feb 09 2003 Graph of a cubic function with 3 real roots where the curve crosses the horizontal axis at y 0.
Now do the same with the three remaining equations to leave two. One property common to each of these curves is that it will intersect. Solve for the unknowns and you have your cubic equation. Just as a quadratic equation may have two real roots so a cubic equation has possibly three.
