Answer:
x ≈ 4.239
Explanation:
A relative minimum is found at the bottom of any U-shape on the graph. If you expand the graph shown until it has a suitable scale, it can show you the relative minimum occurs at x ≈ 4.239.
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Additional comment
The relative maximum occurs at the top of any ∩-shape. The graphing calculator can show you that occurs at x ≈ -1.573.