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3×3 Matrix Determinant — Free Online Calculator

Calculates the determinant of a 3×3 matrix.

What is it?

The 3×3 determinant calculator computes the determinant by cofactor expansion along the first row and tells you whether the matrix is singular (determinant zero, no inverse).

Formula

det = a₁₁(a₂₂a₃₃ − a₂₃a₃₂) − a₁₂(a₂₁a₃₃ − a₂₃a₃₁) + a₁₃(a₂₁a₃₂ − a₂₂a₃₁)

Example

A = [[1,2,3],[4,5,6],[7,8,9]]. det = 1(45 − 48) − 2(36 − 42) + 3(32 − 35) = −3 + 12 − 9 = 0 (singular).

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