How do we have ${\mathbf {v} }^{\mathrm {T} }{\mathbf {v} }={\mathbf {v} }^{\mathrm {T} }Q^{\mathrm {T} }Q{\mathbf {v} }$?
112707
Must $Q^\mathsf{T}Q = I$ if $(Qx)^\mathsf{T}(Qx) = x^\mathsf{T}x$
61604
$V = V_1 + V_2$ confusion? Why is my "proof "incorrect?
38200
Show that $(\mathbf{a}·\mathbf{a})(\mathbf{b}·\mathbf{b})-(\mathbf{a}·\mathbf{b})^2=(\mathbf{a}\times\mathbf{b})·(\mathbf{a}\times\mathbf{b})$?
153355
Given $S \in B(Y^{*}, X^{*})$, does there exist $T\in B(X,Y)$ such that $S=T^{*}$?
148876
What is the meaning of $\mathbf{Q}(\sqrt{2},\sqrt{3})$
50558
What is the name of the operation $v^T H v$?
81879
$Av=λv$ basis proof problems
24072
Intuitive explanation of why $\dim\operatorname{Im} T + \dim\operatorname{Ker} T = \dim V$
90287
How to derive $[x_i, F(\vec p)] = i \hbar \frac {\partial F(\vec p)}{\partial p_i}$
115976
$\mathbf{Q}[\sqrt 5+\sqrt[3] 2]=\mathbf{Q}[\sqrt 5,\sqrt[3] 2]$?
78307
Under what conditions is $AA^T$ invertible?
20110
How to prove $(AB)^T=B^T A^T$
42334
Does $\lambda$ $\mathbf u$ $= 0$ imply $\lambda = 0$ or $\mathbf u$ $= 0$?
71437
How is the derivative of $\textrm{Trace}\left\{ X^T A X B\right\}$ with respect to $X$ equal to $AXB + A^TXB^T$?
125184
Why $\dim(\hom(V,W))=\dim(V) * \dim(W)$?
16644
Why does cancellation of dots $\frac{\partial \dot{\mathbf{r}}_i}{\partial \dot{q}_j} = \frac{\partial \mathbf{r}_i}{\partial q_j}$ work?
148355
Regarding Goldstein's claim that $\mathbf{F} = \dot{\mathbf{p}}$