find the absolute maximum and minimum values of the function over the indicated interval, and indicate the x…

find the absolute maximum and minimum values of the function over the indicated interval, and indicate the x - values at which they occur. f(x)=(x + 5)^(2/3)-3;-8,7
Answer
Explanation:
Step1: Find the derivative
Use the chain - rule. If $y = u^{\frac{2}{3}}$ and $u=x + 5$, then $\frac{dy}{du}=\frac{2}{3}u^{-\frac{1}{3}}$ and $\frac{du}{dx}=1$. So $f^\prime(x)=\frac{2}{3}(x + 5)^{-\frac{1}{3}}=\frac{2}{3\sqrt[3]{x + 5}}$.
Step2: Find the critical points
Set $f^\prime(x)=0$. Since the numerator of $f^\prime(x)$ is non - zero ($2\neq0$), $f^\prime(x)$ has no solution for $f^\prime(x) = 0$. But $f^\prime(x)$ is undefined when $x+5 = 0$, i.e., $x=-5$.
Step3: Evaluate the function at critical and endpoints
Evaluate $f(x)$ at $x=-8,x=-5,x = 7$. For $x=-8$: $f(-8)=(-8 + 5)^{\frac{2}{3}}-3=(-3)^{\frac{2}{3}}-3=\sqrt[3]{9}-3$. For $x=-5$: $f(-5)=(-5 + 5)^{\frac{2}{3}}-3=-3$. For $x = 7$: $f(7)=(7 + 5)^{\frac{2}{3}}-3=12^{\frac{2}{3}}-3=\sqrt[3]{144}-3$.
Step4: Compare the values
We know that $\sqrt[3]{9}-3\approx2.08-3=-0.92$, $-3$, $\sqrt[3]{144}-3\approx5.24-3 = 2.24$.
Answer:
The absolute maximum value is $\sqrt[3]{144}-3\approx2.24$ and it occurs at $x = 7$. The absolute minimum value is $-3$ and it occurs at $x=-5$.