Gaussian Elimination Solver

Row echelon Ax=b

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About Gaussian Elimination Solver

A Gaussian elimination solver for linear systems Ax=b. Performs row operations to reach row echelon form, then back-substitutes. Shows each row operation step-by-step. Detects rank, inconsistency, and free variables. Select from preset systems. All calculations are client-side.

Gaussian Elimination Solver Features

  • Row echelon
  • Back sub
  • Step display
  • Rank
  • Presets
Gaussian elimination: row reduce [A|b] to upper triangular form using elementary row operations (swap, scale, add multiple). Then back-substitute. O(n³/3) operations. The fundamental direct method for linear systems.

How to Use

Set up the system:

  • [A|b]: Augmented matrix
  • Steps: Row operations shown
  • Output: REF + solution

Partial Pivoting

Swap rows to put largest element in pivot position. Prevents division by small numbers (numerical instability). Always used in practice.

Complexity

O(n³/3) multiplications for elimination. O(n²/2) for back-substitution. Total: O(n³/3). LU decomposition is equivalent but stores the work for reuse.

Step-by-Step Instructions

  1. 1Select a system.
  2. 2View row operations.
  3. 3See echelon form.
  4. 4Back-substitute.
  5. 5Get solution.

Gaussian Elimination Solver — Frequently Asked Questions

What are elementary row operations?+

Three types: (1) Swap two rows, (2) Multiply a row by non-zero scalar, (3) Add a multiple of one row to another. Any matrix can be reduced to row echelon form using these operations.

When does the system have no solution?+

When a row becomes [0 0 ... 0 | c] with c≠0. This means 0=c, a contradiction. The system is inconsistent — the equations are contradictory.

What are free variables?+

When rank(A) < n (fewer pivots than unknowns), some variables are 'free' — they can take any value. The solution forms a vector space. Each free variable adds one dimension to the solution space.

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