Answer:
(21,0)
Step-by-step explanation:
The function of the parabola is given in vertex form which is [tex]f(x) = a(x-h)^{2} +k[/tex]
The vertex is equal to (h,k). Looking the function [tex]f(x)=8(x-21)^{2}[/tex], we see that the h-value is equal to 21 and that the k-value is 0. So the vertex of the function is (21,0).