1. **Problem Statement:** Given the function $$d(s) = s^3 + s - 4$$, find the number of local maxima of the function $$n(s)$$, where $$n(s)$$ is related to $$d(s)$$ (assuming $$n(s) = d(s)$$ as no other definition is provided). 2. **Understanding the problem:** To find the number of local maxima of a function, we need to find the critical points by taking the derivative and then determine which of these points correspond to maxima. 3. **Find the derivative:** $$d'(s) = \frac{d}{ds}(s^3 + s - 4) = 3s^2 + 1$$ 4. **Find critical points:** Set the derivative equal to zero: $$3s^2 + 1 = 0$$ $$3s^2 = -1$$ $$s^2 = -\frac{1}{3}$$ Since $$s^2$$ cannot be negative for real numbers, there are no real critical points. 5. **Conclusion:** Since there are no real critical points, the function $$d(s)$$ has no local maxima or minima. **Final answer:** The number of local maxima is **0**.