Question

The profit P (in thousands of dollars) for a company that spends an amount s (in thousands of dollars) on advertising is P = − 1/10s^3 + 15s^2 + 400.
Find the point of diminishing returns.

Answer 1

define "point of diminishing returns", not familiar with this kind of math

Answer 2

point of diminishing returns is the point at which the growth rate of the earnings function begins to decline.