Math Problem Statement

do midpointt only

Approximate the integral ∫₀² (4x³ + x) dx using a midpoint Riemann sum with n = 4 subintervals.

Solution

PIL import Image import pytesseract

Load the image to extract text

image_path = "/mnt/data/1732898641189ln7ivqs3.jpg" extracted_text = pytesseract.image_to_string(Image.open(image_path))

extracted_textTo approximate the integral 02(4x3+x)dx\int_0^2 (4x^3 + x) dx using the midpoint rule with n=4n = 4 subintervals, follow these steps:

Step 1: Calculate Δx\Delta x

The interval [0,2][0, 2] is divided into 4 subintervals: Δx=204=0.5\Delta x = \frac{2 - 0}{4} = 0.5

Step 2: Determine midpoints

The subintervals are: [ [0, 0.5], [0.5, 1], [1, 1.5], [1.5, 2] ] The midpoints are: x1=0.25,x2=0.75,x3=1.25,x4=1.75x_1 = 0.25, \, x_2 = 0.75, \, x_3 = 1.25, \, x_4 = 1.75

Step 3: Evaluate the function f(x)=4x3+xf(x) = 4x^3 + x at the midpoints

f(0.25)=4(0.25)3+0.25=4(0.015625)+0.25=0.0625+0.25=0.3125f(0.25) = 4(0.25)^3 + 0.25 = 4(0.015625) + 0.25 = 0.0625 + 0.25 = 0.3125 f(0.75)=4(0.75)3+0.75=4(0.421875)+0.75=1.6875+0.75=2.4375f(0.75) = 4(0.75)^3 + 0.75 = 4(0.421875) + 0.75 = 1.6875 + 0.75 = 2.4375 f(1.25)=4(1.25)3+1.25=4(1.953125)+1.25=7.8125+1.25=9.0625f(1.25) = 4(1.25)^3 + 1.25 = 4(1.953125) + 1.25 = 7.8125 + 1.25 = 9.0625 f(1.75)=4(1.75)3+1.75=4(5.359375)+1.75=21.4375+1.75=23.1875f(1.75) = 4(1.75)^3 + 1.75 = 4(5.359375) + 1.75 = 21.4375 + 1.75 = 23.1875

Step 4: Compute the midpoint Riemann sum

The formula is: Midpoint Riemann Sum=Δxi=1nf(xi)\text{Midpoint Riemann Sum} = \Delta x \sum_{i=1}^n f(x_i) Midpoint Riemann Sum=0.5[f(0.25)+f(0.75)+f(1.25)+f(1.75)]\text{Midpoint Riemann Sum} = 0.5 \left[f(0.25) + f(0.75) + f(1.25) + f(1.75)\right] Midpoint Riemann Sum=0.5[0.3125+2.4375+9.0625+23.1875]\text{Midpoint Riemann Sum} = 0.5 \left[0.3125 + 2.4375 + 9.0625 + 23.1875\right] Midpoint Riemann Sum=0.535=17.5\text{Midpoint Riemann Sum} = 0.5 \cdot 35 = 17.5

Final Answer:

The approximation of the integral using the midpoint rule is: 17.5\boxed{17.5}

Would you like further explanation or a step-by-step breakdown of any part?

Related Questions:

  1. How is the midpoint rule different from the left or right endpoint Riemann sums?
  2. Can this result be verified by evaluating the exact integral?
  3. What happens if we increase nn to 8 subintervals? How does it affect accuracy?
  4. How can this method be extended to irregular intervals?
  5. How does the midpoint rule compare to the trapezoidal rule?

Tip:

The midpoint rule often provides a better approximation than the left or right Riemann sums because it reduces error by sampling near the "center" of the interval.

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Math Problem Analysis

Mathematical Concepts

Integral approximation
Riemann sums
Midpoint rule

Formulas

Δx = (b - a) / n
Midpoint Riemann Sum = Δx × Σ f(xᵢ)

Theorems

Fundamental theorem of calculus

Suitable Grade Level

Grades 10-12