Extreme Points of the Unit Ball B4 in the Space of Real Polynomials of Degree at most Four with the Supremum Norm

Denote by P
n
the space of real polynomials p of degree at most n equipped with the sup norm on the interval I = [−1, 1]. The unit ball B
n
with respect to the sup norm is a compact convex set. Let EB
n
denote the set of the extreme points of B
n
.