Cofactor Expansion Calculator (2×2)
The Cofactor Expansion Calculator finds the determinant of a 2×2 matrix by expanding along the first row, showing the signed products. Enter the four matrix entries.
Formula
det = a₁₁·a₂₂ − a₁₂·a₂₁ (cofactor expansion along row 1)
- Expanding along the first row: a₁₁·C₁₁ + a₁₂·C₁₂.
- For 2×2, this reduces to the familiar ad − bc.
[[4,1],[2,3]]
Inputs
- a₁₁: 4
- a₁₂: 1
- a₂₁: 2
- a₂₂: 3
4×3 − 1×2 = 12 − 2 = 10.
Frequently asked questions
What is cofactor expansion?
A method to compute a determinant by summing each entry of a row times its signed minor (cofactor).