Category:Vector Cross Product

From ProofWiki
Jump to navigation Jump to search

This category contains results about Vector Cross Product.
Definitions specific to this category can be found in Definitions/Vector Cross Product.

Let $\mathbf a$ and $\mathbf b$ be vectors in a vector space $\mathbf V$ of $3$ dimensions:

\(\ds \mathbf a\) \(=\) \(\ds a_i \mathbf i + a_j \mathbf j + a_k \mathbf k\)
\(\ds \mathbf b\) \(=\) \(\ds b_i \mathbf i + b_j \mathbf j + b_k \mathbf k\)

where $\tuple {\mathbf i, \mathbf j, \mathbf k}$ is the standard ordered basis of $\mathbf V$.


The vector cross product, denoted $\mathbf a \times \mathbf b$, is defined as:

$\mathbf a \times \mathbf b = \begin{vmatrix} \mathbf i & \mathbf j & \mathbf k\\ a_i & a_j & a_k \\ b_i & b_j & b_k \\ \end{vmatrix}$

where $\begin {vmatrix} \ldots \end {vmatrix}$ is interpreted as a determinant.

More directly:

$\mathbf a \times \mathbf b = \paren {a_j b_k - a_k b_j} \mathbf i - \paren {a_i b_k - a_k b_i} \mathbf j + \paren {a_i b_j - a_j b_i} \mathbf k$