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

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SUMMARY

The discussion centers on constructing a step function that approximates the Riemann function defined as f(x) = 1/q for rational x and f(x) = 0 for irrational x, under the constraint that the supremum of the difference between the functions is less than a specified epsilon (essilope). A suggestion was made to restrict q to values less than 1/essilope to facilitate this construction. However, attempts to define the step function as f(X) = 0 over the interval (0,1) failed, particularly at x = 1, where the difference exceeds the desired threshold, indicating that the Riemann function is not Riemann integrable.

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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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