Does $\langle u,Tu \rangle=0$ imply that $T=0$?
7813
In a complex vector space, $\langle Tx,x \rangle=0 \implies T = 0$
122213
Proving that if $\langle Ax,x\rangle =0$ for every $x$, then $A$ is the zero operator
131906
"An operator is hermitian". Implications?
1162
Why $\{\mathbf{0}\}$ has dimension zero?
116427
$(c^{\mu}\partial_{\mu}-m)\phi(x)=0$ not Lorentz-invariant?
11715
Prove that if $\langle Tx,x\rangle =0$ for all $x \in X$, then $T = 0$
83183
Why is $\langle x| x' \rangle=\delta(x-x')$?
57166
Showing that $\Bbb R[x] / \langle x^2 + 1 \rangle$ is isomorphic to $\Bbb C$ question
81380
How fast does the sequence $y_t$ defined by $y_{t+1}=y_t(1-y_t)$ decay to zero?
30996
If $\langle Ta, a\rangle \in \mathbb{R}$ for all $a$ then $T$ is self-adjoint
145600
Is it true that $ U \oplus W_1 = U \oplus W_2 \implies W_1 = W_2 $?
31919
What can we say about the inner product $\langle f(t),f'(t) \rangle$?
104034
Is $\le$ defined by $\langle 𝑥_1, 𝑦_1 \rangle \le \langle 𝑥_2, 𝑦_2 \rangle$, if $𝑥_1 \le 𝑥_2 \land𝑦_1 \ge 𝑦_2$ a linear order?
6202
$V$ be a vector space , $T:V \to V$ be a linear operator , then is $\ker (T) \cap R(T) \cong R(T)/R(T^2) $?
34147
$\|u\|\leq \|u+av\| \Longrightarrow \langle u,v\rangle=0$
9143
Solve $u_{xx}-3u_{xt}-4u_{tt}=0$ where $u(x,0)=x^2$ and $u_t(x,0)=e^x$
102871
$\langle r\rangle$ maximal $\iff r$ irreducible