Math Problem Statement

Suppose f(x) = 2 - cos(x). Suppose F(x) is the unique antiderivative of f(x) that satisfies F(π/2) = 2. Find F(π).

Solution

To solve this problem, we need to determine the antiderivative F(x)F(x) of f(x)=2cos(x)f(x) = 2 - \cos(x) that satisfies the condition F(π2)=2F\left(\frac{\pi}{2}\right) = 2, and then find F(π)F(\pi).

Step-by-Step Solution

  1. Find the Antiderivative F(x)F(x): Since f(x)=2cos(x)f(x) = 2 - \cos(x), we can integrate each term individually: (2cos(x))dx=2dxcos(x)dx\int (2 - \cos(x)) \, dx = \int 2 \, dx - \int \cos(x) \, dx

    • The antiderivative of 22 is 2x2x.
    • The antiderivative of cos(x)-\cos(x) is sin(x)-\sin(x).

    Therefore, we get: F(x)=2xsin(x)+CF(x) = 2x - \sin(x) + C where CC is the constant of integration.

  2. Use the Condition F(π2)=2F\left(\frac{\pi}{2}\right) = 2 to Solve for CC: Substitute x=π2x = \frac{\pi}{2} and F(π2)=2F\left(\frac{\pi}{2}\right) = 2: 2=F(π2)=2π2sin(π2)+C2 = F\left(\frac{\pi}{2}\right) = 2 \cdot \frac{\pi}{2} - \sin\left(\frac{\pi}{2}\right) + C Simplify: 2=π1+C2 = \pi - 1 + C Solving for CC: C=3πC = 3 - \pi

  3. Write the Complete Expression for F(x)F(x): Now we have: F(x)=2xsin(x)+(3π)F(x) = 2x - \sin(x) + (3 - \pi)

  4. Find F(π)F(\pi): Substitute x=πx = \pi: F(π)=2πsin(π)+(3π)F(\pi) = 2 \cdot \pi - \sin(\pi) + (3 - \pi) Since sin(π)=0\sin(\pi) = 0, this simplifies to: F(π)=2π+3π=π+3F(\pi) = 2\pi + 3 - \pi = \pi + 3

Conclusion

The value of F(π)F(\pi) is π+3\pi + 3.

Answer

The correct answer is: 3+π\boxed{3 + \pi}

Would you like further details on any part of this solution?


Here are some related questions for further practice:

  1. How do you find the antiderivative of trigonometric functions like cos(x)\cos(x) and sin(x)\sin(x)?
  2. How can we verify that F(x)F(x) is indeed the antiderivative of f(x)f(x) by differentiating it?
  3. What happens if the initial condition F(π2)=2F\left(\frac{\pi}{2}\right) = 2 is different? How would that affect CC?
  4. How would the solution change if f(x)f(x) had a different form, such as f(x)=2+cos(x)f(x) = 2 + \cos(x)?
  5. How can definite integrals be used to find F(π)F(π2)F(\pi) - F\left(\frac{\pi}{2}\right) directly?

Tip: Always check your antiderivative by differentiating it to ensure it matches the original function.

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Math Problem Analysis

Mathematical Concepts

Calculus
Antiderivatives
Trigonometric Functions

Formulas

Integral of a constant: ∫c dx = cx
Integral of cosine: ∫cos(x) dx = sin(x)

Theorems

Fundamental Theorem of Calculus

Suitable Grade Level

College level