# How do I constrain variables to a user-defined domain in ArgMax?

I am trying to ArgMax a function over x, but x is only defined between [0,1]

How do I do that? I have tried:

ArgMax[f1[x], x ∈ [0,1]]


But it gave me an error. "{x}[Element]" cannot be followed by "[0,1]".

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doesn't ArgMax[{f1[x],0<x<1},x] work? – chris Jul 29 '14 at 7:31

You can use the new (in V10) ImplicitRegion function as follows:
reg = ImplicitRegion[0 <= x <= 1, {x}];

ArgMax[f1[x], x ∈ reg]