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please help me to do this problem...

Let $f: \mathbb R\to \mathbb R$ be a continuous function such that $f(q)=\sin q$ for $q\in\mathbb Q$ (rational numbers). Find the value of f(π/4).

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    Please read: http://meta.math.stackexchange.com/q/18032012-10-16
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    What values could $f$ take on the irational numbers? What would make sense? And if you got this, how do you prove it?2012-10-16
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    I think you are in an exam. Hence I will refrain from answering any more of your question for the next 2 hours.2012-10-16
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    You would make it easier to other people to help you, if you wrote your thoughts about the problem. Otherwise some people might post answers employing some facts you have not learned yet (and thus useless for you). What do you know about continuity? If you know something about dense sets, you might have a look here: [Continuous functions between metric spaces are equal if they are equal on a dense set](http://math.stackexchange.com/questions/202325/). Other possibility: What do you know about continuity and convergent sequences?2012-10-16
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    to Martin,,I referred your link about cts function between metric spaces are equal....but that says about two functions right???here there's only one and I know Q is dense in R and the thing is I cant find any function that is convergent to π/4.2012-10-17

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