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Completing the Square Calculator

Solve polynomial or quadratic expressions using the entered coefficients and values.

📐 Completing the Square Calculator

Convert quadratic equations to vertex form with step-by-step solutions

ax² + bx + c = 0

Results

Results

Results

📝 Detailed Solution Steps

Enter a quadratic equation in the Calculator tab to see detailed steps here.

📊 Parabola Graph and Vertex

Enter a quadratic equation to see its graph and vertex information.

🎓 Completing the Square Theory

Completing the square is a method to convert a quadratic equation from standard form to vertex form, revealing the vertex of the parabola.

Standard Form: ax² + bx + c = 0
Vertex Form: a(x - h)² + k = 0
Where: (h, k) is the vertex of the parabola

General Method:

Step 1: Start with ax² + bx + c
Step 2: Factor out 'a' from x² and x terms: a(x² + (b/a)x) + c
Step 3: Complete the square inside parentheses: add and subtract (b/2a)²
Step 4: Rewrite as perfect square: a(x + b/2a)² + (c - b²/4a)
Step 5: Identify vertex: h = -b/2a, k = c - b²/4a

Example: x² + 6x + 5

Original: x² + 6x + 5
Step 1: Take half of coefficient of x: 6/2 = 3
Step 2: Square it: 3² = 9
Step 3: Add and subtract: x² + 6x + 9 - 9 + 5
Step 4: Group perfect square: (x + 3)² - 9 + 5
Result: (x + 3)² - 4
Vertex: (-3, -4)

Applications:

  • Finding Vertex: Identify the maximum or minimum point of a parabola
  • Solving Quadratics: Alternative to quadratic formula
  • Graphing: Easier to graph when in vertex form
  • Optimization: Find maximum/minimum values in real-world problems
  • Conic Sections: Standard form for parabolas in coordinate geometry

Key Formulas:

  • Vertex x-coordinate: h = -b/(2a)
  • Vertex y-coordinate: k = f(h) = ah² + bh + c
  • Discriminant: Δ = b² - 4ac
  • Axis of Symmetry: x = -b/(2a)

About This Calculator

Use the Completing the Square Calculator to solve polynomial or quadratic expressions from the entered coefficients and variables.

How We Keep This Calculator Reliable

SaralStudy calculators are built for learning, revision and planning with visible formulas and worked examples.

Formula first Each academic calculator shows the calculation rule before the result so students can verify the method.
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