Determinant of scalar product of matrix

Dependencies:

  1. Determinant after elementary row operation

Let $c$ be a scalar and $A$ be an $n$ by $n$ matrix. Then $|cA| = c^n|A|$.

Proof

$cA$ can be obtained from $A$ by applying the elementary row operation $\langle i \rangle \leftarrow c\langle i \rangle$ on each row.

Therefore, $|cA| = c(c(\ldots(c(c|A|))\ldots)) = c^n|A|$.

Dependency for: None

Info:

Transitive dependencies:

  1. Group
  2. Ring
  3. Semiring
  4. Matrix
  5. Submatrix
  6. Determinant
  7. Swapping last 2 rows of a matrix negates its determinant
  8. Elementary row operation
  9. Determinant after elementary row operation