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We have decided to move away from Wix and migrate to wordpress. This offers many advantages to us.

Notably we now have math support, [katex]x^2[/katex].

#invariants

The dot product of a vector with itself is always non-negative, [katex]\mathbf{v} \cdot \mathbf{v} \geq 0[/katex]

The determinant of an orthogonal matrix is always 1, [katex]\det(\mathbf{O}) = 1, \text{where } \mathbf{O} \mathbf{O}^T = \mathbf{I}[/katex]

The trace is invariant under cyclical permutations, [katex]\text{Tr}(\mathbf{A} \mathbf{B} \mathbf{C}) = \text{Tr}(\mathbf{C} \mathbf{A} \mathbf{B})[/katex]

The trace of the matrix is invariant under changes of basis, [katex]\lambda_1 + \lambda_2 + \dots + \lambda_n = \text{Tr}(\mathbf{A})[/katex]

The sum of principle minors is invariant, [katex] \text{det} \begin{pmatrix}
a_{1,1} & & & \\
a_{2,1} & a_{2,2} & & \\
\vdots & & \ddots & \\
a_{n,1} & a_{n,2} & \dots & a_{n,n}
\end{pmatrix} = \sum_{i=1}^n (-1)^{i+j} a_{i,j} \text{det} \begin{pmatrix}
a_{1,1} & a_{1,2} & \dots & a_{1,i-1} & a_{1,i+1} & \dots & a_{1,n} \\
a_{2,1} & a_{2,2} & \dots & a_{2,i-1} & a_{2,i+1} & \dots & a_{2,n} \\
\vdots & \vdots & \ddots & \vdots & \vdots & \ddots & \vdots \\
a_{i-1,1} & a_{i-1,2} & \dots & a_{i-1,i-1} & a_{i-1,i+1} & \dots & a_{i-1,n} \\
a_{i+1,1} & a_{i+1,2} & \dots & a_{i+1,i-1} & a_{i+1,i+1} & \dots & a_{i+1,n} \\
\vdots & \vdots & \ddots & \vdots & \vdots & \ddots & \vdots \\
a_{n,1} & a_{n,2} & \dots & a_{n,i-1} & a_{n,i+1} & \dots & a_{n,n}
\end{pmatrix}[/katex]

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