Finite-dimensional Inner product space, if $A^{2}x=0 \Rightarrow Ax=0$
128361
The kernel and range of the powers of a self-adjoint operator
49087
Show that a norm on an inner product space satisfies parallelogram law.
110545
Space $X$ such that $H_i(X,\mathbb{Z})\neq 0$ but $H_i(X,\mathbb{Z}_3)= 0$
81229
Show that $(C([a,b]),\|{\cdot}\|_2)$ is not a complete normed vector space
155621
Finiteness of the dimension of a normed space and compactness
44685
Inner product on $C(\mathbb R)$
133609
orthonormal system in a Hilbert space
111550
Let $A$ be a square complex matrix of size $n$ then $\langle Ax,x\rangle=0$ for $\forall x \in \Bbb C^n$ $\iff A=0$
138653
Is $\mathbb{R}$ a subspace of $\mathbb{R}^2$?
105141
$\mathbb R[x]/\langle x^2+1\rangle\simeq\mathbb C$ and $\mathbb R[x]/\langle x^2+1\rangle$ contains a zero of $x^2+1$
128985
Show that $\langle x,y\rangle_A = \langle Ax,Ay\rangle$ is an inner product on $\mathbb R^n$
146143
Question about proof that finite-dimensional subspaces of normed vector spaces are direct summands
32064
Zero-dimensional matrices
128917
Inner Product on $\mathbb{R}$ and on $\mathbb{C}$
130045
Show that $l^2$ is a Hilbert space
33642
Finite dimensional subspace of $C([0,1])$
152196
About inner products, norms and metrics