Answer
At $-8, 0, \text{ and }5$, where the values are $-4, 0, \text{ and }0$, respectively.
Work Step by Step
A local minimum is a value that is lower than or equal to all values in any surrounding area. By this, the local minima are found at $-8, 0, \text{ and }5$, where the values are $-4,0, \text{ and }0$, respectively.