# Math Help - how to find cubic polynomial from 4 given points

1. ## how to find cubic polynomial from 4 given points

hi,

i am given four points like (2,0.5),(3,0.3333),(4,.25),(5,02)
how can i get the cubic polynomial from the given points..

2. A cubic polynomial has the form $y = ax^3 + bx^2+cx+d$

Now plug all your values into this equation and you will end up with a system of 4 linear equations which can be solved to find the values of a, b, c and d. A good calculator can do this or I'm sure if you looked up 'simultaneous equations solver' or the like online you can find the solutions.

3. Can't you also use a matrix and elementary column operations to get the values of a,b,c and d?