Calculate a determinant by expanding along the first row and inspecting the cofactor matrix.
Matrix entries must be valid numbers, including decimals and negatives.
Cofactor expansion computes a determinant by choosing a row or column, multiplying each entry by its cofactor, and summing the results. This calculator expands along the first row.
The determinant and cofactors update to match the selected matrix size.
Invalid cells are rejected instead of being silently converted.
The right panel shows the determinant, a short calculation note, and the cofactor matrix.
Matrix [[2, 3], [1, 4]]
det(A) = (2)(4) - (3)(1) = 5
Cofactor matrix = [[4, -1], [-3, 2]]
A cofactor is a signed minor. The sign alternates across the matrix in a checkerboard pattern.
Yes. Negative values and decimals are accepted as long as they are valid numbers.
This keeps the working simple and matches the common textbook form.
The matrix is singular, so the cofactor matrix still exists but the inverse does not.
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