Constructing a Step Function for the Riemann Function with Restrictions on q

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Homework Statement


The reimann function (if x is rational then f(x)=1/q, if x is irrational then f(X)=0)is not a step function,then, for any essilope, construct a step function k:[0,1] ~>R s.t. ||f-k||=sup{|f(t)-k(t)|:t is in[0,1]}<essilope,can someone help me to construct such step function


Homework Equations



suggestion: restrict to q<1/essilope

The Attempt at a Solution


my try is f(X)=0 for(0,1) but it seems doesn't work cause when x=1,|f(x)-0|=1>1/2
 
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The given function is not Riemann integrable so it can't be the limit of step functions.
Maybe you were not accurate in representing the function.what is q?
 
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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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