Topic explanation

Standard explanation

ad-bc. Swapping two rows changes sign. If two rows equal, det=0. det(kA)=k^n det A for n x n.

Key points

• ad minus bc
• 2x2: ad-bc
• 3x3: cofactor expansion
• chessboard signs
• DETERMINANT OF A 2x2 MATRIX: ad-bc. Swapping two rows changes sign. If two rows equal, det=0. det(kA)=k^n det A for n x n.
• 2x2: ad-bc.
• WHAT — DETERMINANT OF A 2x2 MATRIX: ad-bc. Swapping two rows changes sign. If two rows equal, det=0. det(kA)=k^n det A for n x n.
• WHY — Why it matters: This rule is a separate learning unit inside determinants 2x2 and 3x3. It can be defined, applied, a

Labelled diagram