Constant Continuity Adv. Calc 1

chief12
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Homework Statement


suppose f: [a,b] ---> Q is continuous on [a,b]. prove that f is constant on [a,b].

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The Attempt at a Solution



Since there is at least one irrational number between every two rational numbers,
then for f to be continuous in the given scenario, f must be constant

stuck about showing it with delta/epsilon proof
 
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I don't think you need any epsilons and deltas. Just use the intermediate value theorem.
 
Dick said:
I don't think you need any epsilons and deltas. Just use the intermediate value theorem.

can you explain more, a bit lost, test tomorrow
 
chief12 said:
can you explain more, a bit lost, test tomorrow

Look up the intermediate value theorem and tell me what it says.
 
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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