Set The Polynomial Using Coefficients! or should you

Level 2

Let $f(x)$ be a cubic polynomial such that $f(0)=5$ , $f(1)=4$ , $f(2)=17$ , and $f(3)=56$ . Compute $f(4)$ .

133 131 132 130

1 solution

Alan Yan
Sep 8, 2015

Let $f(4) = x$ .

Using Finite Differences along with the fact that $f$ is cubic, you get that $x-121 = 12 \implies x = \boxed{133}$