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# Social Media Posts: Bisection Method for Root Finding12================================================================================3## SHORT-FORM POSTS4================================================================================56### Twitter/X (280 chars)7--------------------------------------------------------------------------------8The bisection method: when in doubt, split it in half!910Finding where f(x) = x³ - x - 2 crosses zero:11→ Start with [1, 2]12→ 37 iterations later: x ≈ 1.5213797068045681314Simple, robust, guaranteed to work.1516#Python #NumericalMethods #Math1718--------------------------------------------------------------------------------1920### Bluesky (300 chars)21--------------------------------------------------------------------------------22Implemented the bisection method for root finding today.2324Given f(x) = x³ - x - 2 on [1, 2]:25• Error halves each iteration: εₙ = (b₀ - a₀)/2ⁿ⁺¹26• Found root x ≈ 1.521379706804568 in 37 iterations27• Linear convergence, but guaranteed to work for any continuous function2829--------------------------------------------------------------------------------3031### Threads (500 chars)32--------------------------------------------------------------------------------33Ever need to find where a function equals zero? The bisection method is your reliable friend.3435Here's how it works:361. Pick an interval [a, b] where f(a) and f(b) have opposite signs372. Check the midpoint c = (a + b)/2383. Narrow down to whichever half contains the root394. Repeat until you're close enough4041For f(x) = x³ - x - 2, starting from [1, 2]:42→ 37 iterations43→ Root: x ≈ 1.52137970680456844→ Error bound: 10⁻¹⁰4546Not the fastest method, but it ALWAYS works. That's the beauty of it.4748--------------------------------------------------------------------------------4950### Mastodon (500 chars)51--------------------------------------------------------------------------------52Exploring the bisection method for root finding.5354For a continuous f(x) with f(a)·f(b) < 0, the Intermediate Value Theorem guarantees a root in (a, b).5556Algorithm:57• Compute midpoint: c = (a + b)/258• Update interval based on sign of f(c)59• Error after n iterations: |r - cₙ| ≤ (b₀ - a₀)/2ⁿ⁺¹6061Results for f(x) = x³ - x - 2 on [1, 2]:62• Root: 1.52137970680456863• 37 iterations for ε = 10⁻¹⁰64• Linear convergence (rate = 1/2)6566Also found the Dottie number solving cos(x) - x = 0!6768#NumericalAnalysis #Python #Mathematics6970--------------------------------------------------------------------------------7172================================================================================73## LONG-FORM POSTS74================================================================================7576### Reddit (r/learnpython or r/math)77--------------------------------------------------------------------------------78**Title:** Visualizing the Bisection Method: A Simple but Powerful Root-Finding Algorithm7980**Body:**8182I created a Jupyter notebook exploring the bisection method, one of the most fundamental algorithms in numerical analysis. Here's what I learned:8384**The Basic Idea (ELI5)**8586Imagine you're playing a number guessing game. Someone picks a number between 1 and 100, and tells you "higher" or "lower" after each guess. The optimal strategy? Always guess the middle.8788That's exactly what the bisection method does for finding roots (where a function equals zero).8990**How It Works**91921. Start with an interval [a, b] where f(a) and f(b) have opposite signs932. The Intermediate Value Theorem guarantees a root exists between them943. Compute the midpoint c = (a + b)/2954. Check which half contains the root (based on sign of f(c))965. Repeat with the new, smaller interval9798**Key Results**99100For f(x) = x³ - x - 2 on [1, 2]:101- Found root x ≈ 1.521379706804568102- Required 37 iterations for tolerance 10⁻¹⁰103- Error bound after n iterations: (b₀ - a₀)/2ⁿ⁺¹104105**Why It Matters**106107The bisection method has LINEAR convergence (error halves each step), which is slower than Newton-Raphson's quadratic convergence. But here's the tradeoff:108109✓ Guaranteed to converge for continuous functions110✓ No derivatives needed111✓ Numerically stable112✗ Needs initial bracketing with sign change113✗ Can't find tangent roots114115**Bonus:** Also found the Dottie number (≈0.739) by solving cos(x) - x = 0. It's the unique fixed point of cosine!116117Check out the full notebook with visualizations:118https://cocalc.com/github/Ok-landscape/computational-pipeline/blob/main/notebooks/published/bisection_method.ipynb119120--------------------------------------------------------------------------------121122### Facebook (500 chars)123--------------------------------------------------------------------------------124Ever wondered how computers find exact solutions to equations?125126The bisection method is beautifully simple: keep cutting the search space in half until you find the answer.127128For the equation x³ - x - 2 = 0:129• Start between 1 and 2130• 37 halvings later → x ≈ 1.5214131132It's like a high-low guessing game, but for math! Slow but guaranteed to work.133134View the interactive notebook:135https://cocalc.com/github/Ok-landscape/computational-pipeline/blob/main/notebooks/published/bisection_method.ipynb136137--------------------------------------------------------------------------------138139### LinkedIn (1000 chars)140--------------------------------------------------------------------------------141Exploring Numerical Methods: The Bisection Algorithm142143Just completed an implementation of the bisection method for root finding—a foundational algorithm in numerical analysis that demonstrates key principles of computational mathematics.144145**Technical Implementation:**146• Python with NumPy/Matplotlib147• Full iteration history tracking148• Convergence visualization and error analysis149150**Key Findings:**151For f(x) = x³ - x - 2 on interval [1, 2]:152• Converged to x = 1.521379706804568 in 37 iterations153• Achieved error bound of 10⁻¹⁰154• Verified theoretical convergence: εₙ = (b₀ - a₀)/2ⁿ⁺¹155156**Why This Matters:**157The bisection method offers guaranteed convergence for continuous functions—critical when reliability matters more than speed. It's often used to:158• Provide initial estimates for faster algorithms (Newton-Raphson)159• Solve problems where derivatives are unavailable160• Handle functions with numerical instabilities161162**Skills Demonstrated:**163• Numerical analysis theory and implementation164• Scientific visualization165• Algorithm convergence analysis166167Full notebook with interactive code:168https://cocalc.com/github/Ok-landscape/computational-pipeline/blob/main/notebooks/published/bisection_method.ipynb169170#NumericalMethods #Python #DataScience #ComputationalMathematics #ScientificComputing171172--------------------------------------------------------------------------------173174### Instagram (500 chars)175--------------------------------------------------------------------------------176Finding where math meets zero177178The bisection method is elegant in its simplicity:179→ Pick an interval180→ Split in half181→ Keep the half with the answer182→ Repeat183184For x³ - x - 2 = 0:185Starting interval: [1, 2]186After 37 halvings: x ≈ 1.5214187188The error halves every single time.189Guaranteed convergence.190No fancy calculus required.191192Sometimes the simplest approach193is the most reliable.194195Swipe to see the convergence plots →196197#NumericalMethods198#Mathematics199#Python200#DataVisualization201#CodingLife202#STEM203#ScienceIsBeautiful204205--------------------------------------------------------------------------------206207208