Get reliable answers to your questions at Westonci.ca, where our knowledgeable community is always ready to help. Discover reliable solutions to your questions from a wide network of experts on our comprehensive Q&A platform. Connect with a community of professionals ready to help you find accurate solutions to your questions quickly and efficiently.

Find a real root of the equation [tex]$x^3 - 6x - 4 = 0$[/tex] using the Bisection method.

Sagot :

To find a real root of the equation [tex]\(x^3 - 6x - 4 = 0\)[/tex] using the Bisection method, we follow a systematic approach. Here's the detailed, step-by-step solution:

### Step 1: Define the function
The function for which we are finding the root is:
[tex]\[ f(x) = x^3 - 6x - 4 \][/tex]

### Step 2: Initial Interval
We need to choose an initial interval [tex]\([a, b]\)[/tex] where the function changes sign (i.e., [tex]\(f(a) \cdot f(b) < 0\)[/tex]). Let's select [tex]\(a = 1\)[/tex] and [tex]\(b = 3\)[/tex].

### Step 3: Check Values at Endpoints
First, evaluate the function at the endpoints of the interval:
[tex]\[ f(1) = 1^3 - 6 \cdot 1 - 4 = -9 \][/tex]
[tex]\[ f(3) = 3^3 - 6 \cdot 3 - 4 = 11 \][/tex]

Since [tex]\(f(1)\)[/tex] is negative and [tex]\(f(3)\)[/tex] is positive ([tex]\(f(1) \cdot f(3) < 0\)[/tex]), there is at least one root in the interval [tex]\([1, 3]\)[/tex].

### Step 4: Calculate Midpoint
Calculate the midpoint of the interval:
[tex]\[ \text{midpoint} = \frac{1 + 3}{2} = 2 \][/tex]

### Step 5: Iterative Bisection Process
To achieve a more accurate root, we repeatedly apply the Bisection method until the interval's length is less than a specified tolerance level, say [tex]\(\text{tolerance} = 10^{-6}\)[/tex]. We follow the iterative process:

1. Evaluate [tex]\(f(\text{midpoint}) = f(2)\)[/tex]:
[tex]\[ f(2) = 2^3 - 6 \cdot 2 - 4 = -8 \][/tex]

2. Determine the new interval based on the sign of [tex]\(f(\text{midpoint})\)[/tex]:
- If [tex]\(f(2) < 0\)[/tex], update [tex]\(a\)[/tex] to the midpoint, and keep [tex]\(b\)[/tex] unchanged, so the new interval becomes [tex]\([2, 3]\)[/tex].

3. Calculate the new midpoint of the next interval:
[tex]\[ \text{midpoint} = \frac{2 + 3}{2} = 2.5 \][/tex]

4. Continue this process, evaluating [tex]\(f(\text{new midpoint})\)[/tex], and refining the interval.

Since the specific tolerance level is [tex]\(10^{-6}\)[/tex], the iteration continues until [tex]\(\frac{b - a}{2}\)[/tex] is sufficiently small and we converge to an approximate root.

### Final Interval and Approximate Root
After several iterations of this process, we narrow down the interval to:
[tex]\[ a \approx 2.7320499420166016 \][/tex]
[tex]\[ b \approx 2.7320518493652344 \][/tex]
And the approximate root (midpoint of this interval) is:
[tex]\[ x \approx 2.732050895690918 \][/tex]

### Conclusion
By using the Bisection method, the real root of the equation [tex]\(x^3 - 6x - 4 = 0\)[/tex] is approximately [tex]\( x \approx 2.7320509 \)[/tex]. This value provides a close approximation to the true root within the specified tolerance.
Thank you for your visit. We're committed to providing you with the best information available. Return anytime for more. We hope our answers were useful. Return anytime for more information and answers to any other questions you have. We're glad you visited Westonci.ca. Return anytime for updated answers from our knowledgeable team.