Minimum value constrained by another set

Question

So I recently stumbled upon an interesting problem that asked to find the equation for $\min_{t<x} t^2$ for all $x\in\mathbb{R}$

I know that $\min_{t} t^2$ describes the minimum of $t^2$ over all possible values of $t$ but I'm not quite sure how to interpret the notation above to find an answer...

Answer 1

$min\{ t^2 : t < x \}$
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