Discontinuous composite of continuous functions

M Dhanota
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Homework Statement



give an example of functions f and g, both continuous at x=0, for which the composite f(g(x)) is discontinuous at x=0. Does this contradict the sandwich theorem? Give reasons for your answer.

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The Attempt at a Solution


I understand the sandwich theorem, but I don't understand how I can just make up these functions! :confused:
 
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If f(g(x)) is discontinuous, what can we say about f(x) or g(x)?
 
I really want to say that one of the functions, either f(x) or G(x) is also discontinuous at a certain point. But not at x=0.
 
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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