Question

how to find the equation of ax3 + bx2 + cx +d with one point (-2,4)

Answer 1

You can't -- you'll need at least four.

Answer 2

oh okay it was a test question, and it was the third part maybe that's a problem.

Answer 3

a) Determine an equation for a family of cubic functions with zeros -4, 0, and 2.
=x3-2x2-8x
b) Write equations for two functions that belong to this family.
1x3+2x2+3x+4
2x3+5x2+3x+1
c) Determine and equation for the member of the family whose graph passes through the point (-2,4).

Would any of this help with solving this problem, or is it a lost cause.