# An algebra problem by Priyanshu Mishra

Algebra Level 5

Let $$f: \mathbb R \rightarrow \mathbb R$$ for all reals $$x, y$$ such that

$\large f( x+y ) + f( x )f( y ) = f( x ) + f( y ) + f( xy ) .$

If only one non-constant function exists satisfying above relation, find $$f(2017)$$.


Notation: $$\mathbb R$$ denotes the set of real numbers.

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