Math Problem Statement

Selesaikan dengan metode biseksi

Solve y = x^3 - 0.5x^2 - 2.5x - 1 = 0 on the interval [-3, 3] using the bisection method.

Solution

To solve the equation y=x30.5x22.5x1=0y = x^3 - 0.5x^2 - 2.5x - 1 = 0 in the interval [3,3][-3, 3] using the bisection method, we will follow these steps:

  1. Step 1: Define the function. The function based on the equation is: f(x)=x30.5x22.5x1f(x) = x^3 - 0.5x^2 - 2.5x - 1

  2. Step 2: Set the interval [3,3][-3, 3].
    The bisection method requires two values aa and bb such that f(a)f(b)<0f(a) \cdot f(b) < 0, meaning the function must change sign between aa and bb.

  3. Step 3: Iterate using bisection.
    We bisect the interval [a,b][a, b] by calculating the midpoint m=a+b2m = \frac{a + b}{2} and evaluating f(m)f(m). If f(m)=0f(m) = 0, then mm is the root. If f(m)0f(m) \neq 0, we update the interval:

    • If f(a)f(m)<0f(a) \cdot f(m) < 0, set b=mb = m.
    • If f(b)f(m)<0f(b) \cdot f(m) < 0, set a=ma = m. We repeat this process until the interval becomes sufficiently small.

Let me compute this for you.Using the bisection method, the root of the equation y=x30.5x22.5x1=0y = x^3 - 0.5x^2 - 2.5x - 1 = 0 in the interval [3,3][-3, 3] is approximately x2.0x \approx 2.0, found after 19 iterations with a tolerance of 10510^{-5}.

Would you like further details or clarifications on any step?

Here are 5 related questions to extend your understanding:

  1. How does the tolerance affect the accuracy of the bisection method?
  2. Why is it necessary for the function values at the endpoints to have opposite signs?
  3. How can we verify that the root found is accurate to the desired tolerance?
  4. What happens if the function does not change signs within the interval?
  5. Can the bisection method find multiple roots in an interval?

Tip: The bisection method is reliable but may converge slowly, especially if the root is near the endpoints.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Numerical Methods
Polynomials
Bisection Method

Formulas

Bisection formula: m = (a + b) / 2
Polynomial equation: f(x) = x^3 - 0.5x^2 - 2.5x - 1

Theorems

Intermediate Value Theorem: guarantees a root in an interval where the function changes sign

Suitable Grade Level

Grades 11-12, Early College