Max Min Cubic F14045
1. **Problem:** Find the maximum and minimum values of the function $$y = x^3 - 3x + 2$$.
2. **Formula and rules:** To find maxima and minima, we use the first derivative test. Find $$y'$$ and set it equal to zero to find critical points.
3. **Calculate the derivative:**
$$y' = \frac{d}{dx}(x^3 - 3x + 2) = 3x^2 - 3$$
4. **Find critical points:**
Set $$y' = 0$$:
$$3x^2 - 3 = 0 \implies x^2 = 1 \implies x = \pm 1$$
5. **Second derivative test:**
Calculate $$y''$$:
$$y'' = \frac{d}{dx}(3x^2 - 3) = 6x$$
Evaluate at critical points:
- At $$x = 1$$: $$y''(1) = 6(1) = 6 > 0$$, so $$x=1$$ is a local minimum.
- At $$x = -1$$: $$y''(-1) = 6(-1) = -6 < 0$$, so $$x=-1$$ is a local maximum.
6. **Find function values at critical points:**
- $$y(1) = 1^3 - 3(1) + 2 = 1 - 3 + 2 = 0$$
- $$y(-1) = (-1)^3 - 3(-1) + 2 = -1 + 3 + 2 = 4$$
7. **Conclusion:**
- Maximum value is $$4$$ at $$x = -1$$.
- Minimum value is $$0$$ at $$x = 1$$.