What is your difficulty? Do you know thedefinitionof "uniformly continuous"?

(First point you need to deal with is that youcannotprove the statement as given- it isn't true! f(x)= sin(x)/x is notdefinedat x= 0 and so cannot be continuous there. The function "f(x)= sin(x)/x for xnot equal to 0, f(0)= 1" is uniformly continuous in R.)