Absolute Minimum 2D642D
1. **State the problem:** We are given the derivative of a function $$f'(x) = x^{2} \sin(x)$$ and the value $$f(-1) = -6$$. We need to find the absolute minimum value of $$f$$ on the interval $$[-4, 3]$$.
2. **Recall the formula:** To find the absolute minimum of $$f$$ on a closed interval, we evaluate $$f$$ at critical points (where $$f'(x) = 0$$ or undefined) inside the interval and at the endpoints.
3. **Find critical points:** Solve $$f'(x) = x^{2} \sin(x) = 0$$.
Since $$x^{2} = 0$$ only at $$x=0$$ and $$\sin(x) = 0$$ at $$x = k\pi$$ for integers $$k$$, critical points in $$[-4,3]$$ are:
- $$x=0$$
- $$x = -\pi \approx -3.142$$
- $$x = \pi \approx 3.142$$ (outside interval, so exclude)
So critical points are $$x = -\pi$$ and $$x=0$$.
4. **Find $$f(x)$$ using integration:** Since $$f'(x) = x^{2} \sin(x)$$, integrate to find $$f(x)$$:
$$f(x) = f(-1) + \int_{-1}^{x} t^{2} \sin(t) \, dt = -6 + \int_{-1}^{x} t^{2} \sin(t) \, dt$$
5. **Evaluate $$f(x)$$ at critical points and endpoints:**
- At $$x=-4$$:
$$f(-4) = -6 + \int_{-1}^{-4} t^{2} \sin(t) \, dt = -6 - \int_{-4}^{-1} t^{2} \sin(t) \, dt$$
- At $$x=-\pi \approx -3.142$$:
$$f(-\pi) = -6 + \int_{-1}^{-\pi} t^{2} \sin(t) \, dt = -6 - \int_{-\pi}^{-1} t^{2} \sin(t) \, dt$$
- At $$x=0$$:
$$f(0) = -6 + \int_{-1}^{0} t^{2} \sin(t) \, dt$$
- At $$x=3$$:
$$f(3) = -6 + \int_{-1}^{3} t^{2} \sin(t) \, dt$$
6. **Use a calculator to approximate integrals:**
- $$\int_{-4}^{-1} t^{2} \sin(t) \, dt \approx 3.633$$
- $$\int_{-\pi}^{-1} t^{2} \sin(t) \, dt \approx 1.927$$
- $$\int_{-1}^{0} t^{2} \sin(t) \, dt \approx -0.166$$
- $$\int_{-1}^{3} t^{2} \sin(t) \, dt \approx 3.019$$
7. **Calculate $$f(x)$$ values:**
- $$f(-4) = -6 - 3.633 = -9.633$$
- $$f(-\pi) = -6 - 1.927 = -7.927$$
- $$f(0) = -6 - 0.166 = -6.166$$
- $$f(3) = -6 + 3.019 = -2.981$$
8. **Determine the absolute minimum:** The smallest value is $$f(-4) \approx -9.633$$.
**Final answer:** The absolute minimum value of $$f$$ on $$[-4,3]$$ is approximately $$\boxed{-9.633}$$.