Written by the Fiveable Content Team โข Last updated September 2025
Written by the Fiveable Content Team โข Last updated September 2025
Definition
A local minimum is a point on the graph of a function where the function value is lower than all nearby points. It represents the lowest value within a specific interval.
5 Must Know Facts For Your Next Test
A local minimum occurs where the first derivative, $f'(x)$, changes from negative to positive.
At a local minimum, the first derivative equals zero or does not exist.
The second derivative test can confirm if a critical point is a local minimum: if $f''(x) > 0$, it's a local minimum.
Local minima are important for understanding the behavior of polynomial functions within certain intervals.
Graphically, a local minimum appears as the bottom point of a valley on the graph of the function.
Review Questions
Related terms
Critical Point: A point on the graph where the first derivative is zero or undefined and potential locations for local maxima and minima.
Second Derivative Test: A method used to determine whether a critical point is a local maximum or minimum by analyzing the sign of the second derivative at that point.
Inflection Point: A point on the curve where the concavity changes, indicated by changes in sign in $f''(x)$.