 #1
 142
 26
Homework Statement:
 With the definition of continuity and the formal definition of the limit value prove that: Let f:R→R be a function f that is continuous in x=0 and has the property that if x≠0 then f(x)≥0. Then f(0)≥0.
Relevant Equations:

The formal definiton of the limit value
Definition of continuity
I have been struggling with this problem and also my friends. We are not the best at epsilondelta proof and we have not found an understandable solution to this problem.