Get reliable answers to your questions at Westonci.ca, where our knowledgeable community is always ready to help. Explore our Q&A platform to find reliable answers from a wide range of experts in different fields. Our platform provides a seamless experience for finding reliable answers from a network of experienced professionals.

Determine whether Rolle's Theorem can be applied to [tex]\( f \)[/tex] on the closed interval [tex]\([a, b]\)[/tex]. Select all that apply.

[tex]\[ f(x) = x^{2/3} - 8, \quad [-27, 27] \][/tex]

A. Yes, Rolle's Theorem can be applied.
B. No, because [tex]\( f \)[/tex] is not continuous on the closed interval [tex]\([a, b]\)[/tex].
C. No, because [tex]\( f \)[/tex] is not differentiable in the open interval [tex]\((a, b)\)[/tex].
D. No, because [tex]\( f(a) \neq f(b) \)[/tex].

If Rolle's Theorem can be applied, find all values of [tex]\( c \)[/tex] in the open interval [tex]\((a, b)\)[/tex] such that [tex]\( f'(c) = 0 \)[/tex]. Enter a comma-separated list. If Rolle's Theorem cannot be applied, enter NA.

[tex]\[ c = \][/tex]

[tex]\[ \square \][/tex]


Sagot :

To determine whether Rolle's Theorem can be applied to the function [tex]\( f \)[/tex] on the closed interval [tex]\([a, b]\)[/tex], we need to verify the following three conditions of Rolle's Theorem:

1. [tex]\( f \)[/tex] is continuous on the closed interval [tex]\([a, b]\)[/tex].
2. [tex]\( f \)[/tex] is differentiable on the open interval [tex]\((a, b)\)[/tex].
3. [tex]\( f(a) = f(b) \)[/tex].

Let's analyze each condition in detail for the function [tex]\( f(x) = x^{2/3} - 8 \)[/tex] on the interval [tex]\([-27, 27]\)[/tex].

### 1. Continuity

The function [tex]\( f(x) = x^{2/3} - 8 \)[/tex] is a composition of elementary functions [tex]\( x^{2/3} \)[/tex] and a constant [tex]\( -8 \)[/tex]. The function [tex]\( x^{2/3} \)[/tex] is continuous everywhere. Consequently, the function [tex]\( f(x) \)[/tex] is continuous on the closed interval [tex]\([−27, 27]\)[/tex].

### 2. Differentiability

To determine if [tex]\( f \)[/tex] is differentiable on the open interval [tex]\((a, b) = (−27, 27)\)[/tex], we take the derivative of [tex]\( f \)[/tex]:

[tex]\[ f'(x) = \frac{d}{dx}(x^{2/3} - 8) \][/tex]
[tex]\[ f'(x) = \frac{2}{3}x^{-1/3} \][/tex]

The function [tex]\( f'(x) = \frac{2}{3}x^{-1/3} \)[/tex] is not defined at [tex]\(x = 0\)[/tex] because it involves a negative fractional power of [tex]\( x \)[/tex]. This means [tex]\( f \)[/tex] is not differentiable at [tex]\( x = 0 \)[/tex]. Therefore, [tex]\( f \)[/tex] is not differentiable on the entire open interval [tex]\((−27, 27)\)[/tex].

### 3. Equal Function Values at Endpoints

Next, we check if [tex]\( f(a) = f(b) \)[/tex]:
[tex]\[ f(-27) = (-27)^{2/3} - 8 = 9 - 8 = 1 \][/tex]
[tex]\[ f(27) = 27^{2/3} - 8 = 9 - 8 = 1 \][/tex]

Since [tex]\( f(-27) = f(27) \)[/tex], this condition is satisfied.

### Conclusion

Rolle's Theorem cannot be applied because the function [tex]\( f(x) \)[/tex] is not differentiable at [tex]\( x = 0 \)[/tex] within the open interval [tex]\( (-27, 27) \)[/tex].

### Values of [tex]\( c \)[/tex]

Since Rolle's Theorem cannot be applied, we should enter "NA" for the values of [tex]\( c \)[/tex]:

[tex]\[ c = \boxed{\text{NA}} \][/tex]

So summarizing the answers, the appropriate response is:
- No, because [tex]\( f \)[/tex] is not differentiable in the open interval [tex]\( (a, b) \)[/tex].

And for the values of [tex]\( c \)[/tex]:
[tex]\[ c = \boxed{\text{NA}} \][/tex]
Thank you for visiting. Our goal is to provide the most accurate answers for all your informational needs. Come back soon. We appreciate your time. Please revisit us for more reliable answers to any questions you may have. Westonci.ca is here to provide the answers you seek. Return often for more expert solutions.