Why must normalisable eigenfunctions have $E > V_{min}$?
44817
Lower bound on energy is potential minimum
46265
Minimal polynomial of the operator $T:V\oplus W\to V\oplus W$
119947
Can a non-zero vector have zero image under every linear functional?
4509
Proof that an involutory matrix has eigenvalues 1,-1
64836
Functions that are always less than their derivatives
47637
Are strict local minima of a general function always countable?
69547
Find the eigenvector associated with the smallest eigenvalue, not smallest in magnitude
78654
An example of a norm which can't be generated by an inner product
68132
Small positive eigenvalues found for a negative definite matrix
98323
If A is invertible, prove that $\lambda \neq 0$, and $\vec{v}$ is also an eigenvector for $A^{-1}$, what is the corresponding eigenvalue?
137983
Normalisation of $k[x,y]/(y^2-x^2(x-1))$
73406
Prove that $E_{\lambda}(T)=E_{\lambda^{-1}}(T^{-1})$ if $T$ is an invertible linear operator on a finite dimensional vector space $V$
39179
Why is $(0, 0)$ not a minimum of $f(x, y) = (y-3x^2)(y-x^2)$?
91348
Why is the Ideal Norm Multiplicative?
128453
If $A$ has two eigenvalues $\lambda _1, \lambda_2$ and $\dim (E_{\lambda_1})=n-1$, then $A$ is diagonalizable
56670
The intuition behind generalized eigenvectors
30268
Positive definite matrix must be Hermitian