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

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 $x=-5$.