how to compare the max-distance between two points to an constant

Hi, i got these data and i'm supposed to get the max-distance between these points with another p(2,5) and to compare it with an constant E(~3.5). The points with the distance inferior to E will be out. x = [1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20]; y = [1 0 -2 5 9 5.5 4 10 12 7 -5 1.7 -1.3 3.3 2 9 1 -5 -8 3] Kind regards Emma