Math 2.0

statement proposition

Determinant of a matrix with a zero row

Statement

Let KK be a commutative ring and let AA be an n×nn \times n matrix over KK. If one row of AA is zero, then det⁡A=0\det A = 0, where det⁡\det is the determinant.

Remarks

This follows from linearity in that row: the zero row is 00 times itself, so det⁡A=0⋅det⁡A=0\det A = 0 \cdot \det A = 0. The same holds for a zero column.

Explanations

L1 human

A zero row means that one edge of the box spanned by the rows has length zero. Such a box has no volume. So the determinant is zero.

What this node needs for W1
  • an inventory row: the row of the inventory that the node accounts for (0 of 1)

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To read this node, read these 9 nodes in this order. The foundations come first, and the list ends with this node.

Each node uses the nodes above it. The colour of the bar on a box shows the evidence level, and the box also gives it as text. The list below has the same nodes.
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  1. Identity matrix object
  2. Matrix definition
  3. Vector space definition
  4. Square matrix definition
  5. Linear map definition
  6. Multilinear map definition
  7. Alternating multilinear map definition
  8. Determinant definition
  9. Determinant of a matrix with a zero row statement

Sources

  1. Web https://en.wikipedia.org/wiki/Determinant, Basic rules