+A **concave function** is a function where the line segment connecting any two points on its graph lies below or on the graph itself, forming a downward-curving shape. Equivalently, its [Epigraph](/wiki/epigraph) is a [Convex Set](/wiki/convex_set). It is the negative counterpart of a [Convex Function](/wiki/convex_function) and vital in optimization problems.
+## See also
+- [Convex Function](/wiki/convex_function)
+- [Optimization](/wiki/optimization)
+- [Convexity](/wiki/convexity)
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