Proving Continuity of g: C0([0, 1]) x [0, 1]-->R

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Homework Statement


Let C0([0, 1]) be the set of continuous functions on the interval [0, 1] with the supremum topology. Prove that the map given by g: C0([0, 1]) x [0, 1]-->R given by g(f, a) = f(a) is continuous.


The Attempt at a Solution


I was originally thinking that maybe I could use the Urysohn lemma to show continuity, but I could not figure out how to make that work in a proof. The simpler method of looking at pre-images of g has also not yielded any insight so far. Any help would be appreciated.
 
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Can't you just show it directly? Given f and a you want to make |f(a) - g(b)| small if g is close to f in the sup norm and a is close to b. Try adding and subtracting f(b).
 
Ok, you want to show |f1(a1)-f(a)| is close to 0 where f1 is close to f in the supremum topology and a1 is close to a. Did you use that f is uniformly continuous on [0,1] since [0,1] is compact?
 
Yeah, you're right. I was over thinking the problem. Thanks for the help.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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