Math Problem Statement

Use the Mean Value Theorem and find all points 0 < c < 2 such that f(2) - f(0) = f'(c) * (2 - 0) : f(x) = x^3.

Solution

To solve this problem using the Mean Value Theorem (MVT), let’s proceed step-by-step:

Problem Statement Recap

You are asked to find all points cc in the interval (0,2)(0, 2) such that: f(2)f(0)=f(c)(20)f(2) - f(0) = f'(c) \cdot (2 - 0) where f(x)=x3f(x) = x^3.

Step 1: Apply the Mean Value Theorem

The Mean Value Theorem states that if f(x)f(x) is continuous on [a,b][a, b] and differentiable on (a,b)(a, b), then there exists a point c(a,b)c \in (a, b) such that: f(c)=f(b)f(a)baf'(c) = \frac{f(b) - f(a)}{b - a} In our case:

  • f(x)=x3f(x) = x^3, so it is continuous and differentiable everywhere on [0,2][0, 2].
  • We set a=0a = 0 and b=2b = 2.

Step 2: Calculate f(2)f(2) and f(0)f(0)

For f(x)=x3f(x) = x^3: f(2)=23=8f(2) = 2^3 = 8 f(0)=03=0f(0) = 0^3 = 0

Thus, f(2)f(0)=80=8f(2) - f(0) = 8 - 0 = 8

Step 3: Apply MVT to Find cc

Using the MVT, we need c(0,2)c \in (0, 2) such that: f(c)(20)=8f'(c) \cdot (2 - 0) = 8 or equivalently, f(c)=82=4f'(c) = \frac{8}{2} = 4

Step 4: Calculate f(x)f'(x) and Solve for cc

Now, find f(x)f'(x) for f(x)=x3f(x) = x^3: f(x)=3x2f'(x) = 3x^2

Set f(c)=4f'(c) = 4: 3c2=43c^2 = 4 c2=43c^2 = \frac{4}{3} c=±43=±23=±233c = \pm \sqrt{\frac{4}{3}} = \pm \frac{2}{\sqrt{3}} = \pm \frac{2 \sqrt{3}}{3}

Since we need c(0,2)c \in (0, 2), we take the positive solution: c=233c = \frac{2 \sqrt{3}}{3}

Conclusion

The point cc in the interval (0,2)(0, 2) that satisfies the Mean Value Theorem for this function is: c=233c = \frac{2 \sqrt{3}}{3}

Would you like further details or have any questions?

Here are some related questions to deepen your understanding:

  1. How would the result change if f(x)f(x) was a different polynomial function?
  2. What are the conditions required for the Mean Value Theorem to hold?
  3. Can you apply the Mean Value Theorem to non-polynomial functions?
  4. How does the Mean Value Theorem relate to Rolle's Theorem?
  5. What is the geometric interpretation of the Mean Value Theorem?

Tip: When using the Mean Value Theorem, ensure the function is continuous on the closed interval and differentiable on the open interval to apply it correctly.

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Math Problem Analysis

Mathematical Concepts

Calculus
Differentiation
Mean Value Theorem

Formulas

Mean Value Theorem: f(b) - f(a) = f'(c) * (b - a)
Derivative of f(x) = x^3: f'(x) = 3x^2

Theorems

Mean Value Theorem

Suitable Grade Level

Grades 11-12 or early college