$\sqrt{X}$ where $X$ is a positive definite matrix is smooth $C^{\infty}$
64741
The square root of positive definite matrix
75211
Theorem about positive matrices
133149
Inverse of a Positive Definite
115296
Under what conditions does a matrix $A$ have a square root?
18470
A practical way to check if a matrix is positive-definite
117419
Why is $e^{x}$ not uniformly continuous on $\mathbb{R}$?
149536
Why is the  $L_p$ norm strictly convex for $1<p<\infty?$
6960
Necessary and sufficient condition for the matrix $A = I - 2 x x^t$ to be orthogonal
139530
Taking derivatives with respect to a matrix
88746
Positive definiteness of the matrix $A+B$
150572
Explicit norm on $\mathcal{C}^0(\mathbb{R},\mathbb{R})$
86623
Why is $B^TB+\lambda\Omega$ positive definite?
5881
$\sqrt x$ is uniformly continuous
90964
Prove: symmetric positive definite matrix
36775
Matrix semi-positive definite
144112
Show that $c_0$ is a Banach space with the norm $\rVert \cdot \lVert_\infty$
120784
Differentiablility over closed intervals