Math Problem Statement

Using simpson's rule to approximate sin(x) dx between 0 and pi, how large do we need to choose n so that our approximation is accurate to within 0.001? Also, approximate this interval using simpson's rule with the number of subintervals determined.

Solution

To solve this problem using Simpson's Rule, we need to:

  1. Estimate the required number of subintervals nn so that the error is within 0.0010.001.
  2. Approximate the integral of sin(x)\sin(x) from 0 to π\pi using Simpson's Rule with the calculated nn.

Step 1: Error Bound for Simpson's Rule

The error for Simpson’s Rule is given by the formula:

ESM(ba)5180n4|E_S| \leq \frac{M(b - a)^5}{180n^4}

Where:

  • ESE_S is the error of the approximation.
  • MM is an upper bound for the fourth derivative of the function on the interval.
  • a=0a = 0, b=πb = \pi are the limits of integration.
  • nn is the number of subintervals, which must be even.
  • 180180 is a constant from Simpson's Rule error formula.

Finding MM (the maximum of the fourth derivative):

  • The fourth derivative of sin(x)\sin(x) is simply sin(x)\sin(x), since the sine function repeats its derivatives every four steps.
  • The maximum value of sin(x)|\sin(x)| over the interval [0,π][0, \pi] is 1, so M=1M = 1.

Thus, the error bound becomes:

ESπ5180n4|E_S| \leq \frac{\pi^5}{180n^4}

We want the error to be less than 0.0010.001, so we set the inequality:

π5180n40.001\frac{\pi^5}{180n^4} \leq 0.001

Step 2: Solving for nn

Now, solve this inequality for nn:

n4π50.001×180n^4 \geq \frac{\pi^5}{0.001 \times 180}

Let me compute the right-hand side of this inequality.From the calculation, n46.42n^4 \geq 6.42, meaning that nn should be at least 7. However, since Simpson's Rule requires nn to be even, the smallest possible value of nn is 88.

Step 3: Approximation using Simpson's Rule

Now, let's approximate the integral of sin(x)\sin(x) from 00 to π\pi using Simpson's Rule with n=8n = 8.

Simpson's Rule formula is:

abf(x)dxh3[f(x0)+4f(x1)+2f(x2)+4f(x3)++f(xn)]\int_a^b f(x) \, dx \approx \frac{h}{3} \left[ f(x_0) + 4f(x_1) + 2f(x_2) + 4f(x_3) + \dots + f(x_n) \right]

Where:

  • h=banh = \frac{b - a}{n}
  • x0=ax_0 = a, xn=bx_n = b
  • xi=a+ihx_i = a + i \cdot h for i=0,1,,ni = 0, 1, \dots, n

Let me calculate the Simpson's Rule approximation for 0πsin(x)dx\int_0^\pi \sin(x) \, dx.It seems like I can’t do more advanced data analysis right now. Please try again later. However, you can still follow these steps to approximate the integral of sin(x)\sin(x) using Simpson's Rule:

  1. Divide the interval [0,π][0, \pi] into n=8n = 8 subintervals.
  2. Use the formula for Simpson’s Rule to compute:

0πsin(x)dxh3[f(x0)+4f(x1)+2f(x2)+4f(x3)++f(xn)]\int_0^\pi \sin(x) \, dx \approx \frac{h}{3} \left[ f(x_0) + 4f(x_1) + 2f(x_2) + 4f(x_3) + \dots + f(x_n) \right]

Where h=π08=π8h = \frac{\pi - 0}{8} = \frac{\pi}{8}.

This will give you an accurate approximation for the integral. If you need further clarification or would like help with something else, feel free to ask!

Relative Questions:

  1. How does the error formula change if we use the trapezoidal rule instead of Simpson's Rule?
  2. How does Simpson’s Rule perform compared to other numerical integration techniques for smooth functions like sine?
  3. Can Simpson’s Rule handle discontinuous functions, and how would the error behave?
  4. What is the geometric interpretation of Simpson’s Rule?
  5. How would increasing nn further impact the accuracy of Simpson's Rule?

Tip:

For functions with higher oscillations or non-smooth behavior, increasing nn can drastically improve Simpson’s Rule accuracy!

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Math Problem Analysis

Mathematical Concepts

Numerical Integration
Simpson's Rule
Error Analysis

Formulas

Simpson's Rule: ∫_a^b f(x) dx ≈ (h/3) [f(x_0) + 4f(x_1) + 2f(x_2) + ... + f(x_n)]
Error Bound for Simpson's Rule: |E_S| ≤ (M(b - a)^5) / (180n^4)

Theorems

Error Bound for Simpson's Rule

Suitable Grade Level

Grades 11-12 or Undergraduate