$\sup\{(f+g)\}\leq \sup\{f\}+\sup \{g\}$
10859
Prove $\sup(f+g) \le \sup f + \sup g$
65062
Prove $\text{rank}(A) \geq \frac{(\text{tr}(A))^2}{\text{tr}(A^2)}$ when $A$ is Hermitian
113411
If $E$ is generated by $E_1$ and $E_2$, then $[E:F]\leq [E_1:F][E_2:F]$?
60520
Upper bound for $|f(0)|$ based on its behavior within the unit disk.
62879
Question about the proof of $GCH$ holds in $\mathbf L$
257
Prove that : $m_{a}m_{b}m_{c}\leq\frac{Rs^{2}}{2}$
91085
how to find $|GL_2(F_p)|$
93806
$\|f\|_{L^{p}}=\sup\left\{\int_{{\bf R}^{n}}|f(x)g(x)|~dx:\|g\|_{L^{q}}\le1\right\}$
53005
Properties of $\liminf$ and $\limsup$ of sum of sequences: $\limsup s_n + \liminf t_n \leq \limsup (s_n + t_n) \leq \limsup s_n + \limsup t_n$
26741
How to prove for $s<1,|a+b|^s\le|a|^s+|b|^s$
88687
Proof of the inequality $||a+b|^p - |a|^p| \leq \epsilon |a|^p + C_{\epsilon} |b|^p$
35547
Does $\{f_ng_n\}\to fg$ uniformly?
149664
Norm is sup of inner products (proof).
96931
Supremum and infimum of $\{\frac{1}{n}-\frac{1}{m}:m, n \in \mathbb{N}\}$
143900
how can be prove that $\max(f(n),g(n)) = \Theta(f(n)+g(n))$
19804
How to prove that $|w_{n+1}-w_n| \leq (2/3)^2 |w_n - w_{n-1}|$?
63526
Proving that $(\sup_{x\in R}|f'(x)|)^2\leq 4\sup_{x\in R}|f(x)|\cdot\sup_{x\in R}|f''(x)|$.