Proof that if $ax = 0_v$ either a = 0 or x = 0
3433
Proof if $a \vec v = 0$ then $a = 0$ or $\vec v = 0$
14161
Proof of when is $A=X^TX$ invertible?
76790
Condition to guarantee $f=0$ on $[a,b]$
125763
If $\mathrm{tr}(A)=0$, then we have $A=BC-CB?$
89537
$ \int_0^x f(t)dt=\int_0^{ax}f(t)dt+ \int_0^{bx}f(t)dt$ implies $f$ constant
81181
Prove that $\det(M-I)=0$ if $\det(M)=1$ and $MM^T=I$
57981
Alternative proof of $a\times0= 0$
106398
If $A$ is invertible show that $\det(A) \neq 0$
31783
Is this proof of $ab = 0$ correct?
61274
If $AA^T$ is the zero matrix, then $A$ is the zero matrix
149287
Prove that $A,B>0$ and $A_{ij}0$
11715
Prove that if $\langle Tx,x\rangle =0$ for all $x \in X$, then $T = 0$
6169
If $ A^3=A$ prove that $Ker\left(A-I\right)+Im\left(A-I\right)=V$
131998
let ${v_1}, {v_2} $ be orthonormal basis for subspace $W$. Prove that if $z$ is a vector in $W$, then
152693
If $C|a$ and $C|b$ then $C|(ax+by)$
150720
Given that $W$ is a subspace of $V$, prove: $\dim W=\dim V \implies W=V$
35631
$H_0(X,A) = 0 \iff A \cap X_i \neq \emptyset \forall $ path-components $X_i$