$f(x)$ is a quadratic function in $x$. The graph of $y = f(x)$ passes through the point $(1, -1)$ and has a turning point at $(-1, 3)$. Find an expression for $f(x)$.
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$f(x)$ is a quadratic function in $x$.
The graph of $y = f(x)$ passes through the point $(1, -1)$ and has a turning point at $(-1, 3)$.
Find an expression for $f(x)$.