Is it true that $|x + y| \geq |x| - |y|$?
108704
Help with proof of $|x+y| \geq |x|-|y|$
76863
How to show $ \sup \inf g(x,y) \leq \inf \sup g(x,y)$?
79040
Graph of $|x| + |y| = 1$
28088
When is $f_{xy}(x,y)\neq f_{yx}(x,y)?$
32149
Proof of the inequality $(x+y)^n\leq 2^{n-1}(x^n+y^n)$
121353
If $x$ and $y$ are not both $0$ then $ x^2 +xy +y^2> 0$
16550
Is $ d(X) \le s(X)? $
74502
Proving the bijection of a continuous function $f$ such that $|f(x)-f(y)| \geq \log(1+|x-y|) \forall x,y$ in $\mathbb{R}.$
111316
PROVE if $x \ge-1 $then $ (1+x)^n \ge 1+nx $ , Every $n \ge 1$
137614
$\left|\frac{x}{|x|}-\frac{y}{|y|}\right|\leq |x-y|$, for $|x|, |y|\geq 1$?
118212
Is it true that $A^A\simeq P(A)$?
81618
Prove $||a|-|b| | \leq |a-b|$
27570
Prove $(1-x)\ln(1-x)+(1+x)\ln(1+x)\leq 2x^2$ for $0<x<1$
4278
Is $\frac{\vert x+y\vert}{1+\vert x+y\vert}\leq\frac{\vert x\vert}{1+\vert x\vert}+\frac{\vert y\vert}{1+\vert y\vert}$ true?
14952
Prove: $\frac{x}{\sqrt{y}}+\frac{y}{\sqrt{x}}\geq \sqrt{x}+\sqrt{y}$
76884
Are $X$ and $X+Y$ independent, if $X$ and $Y$ are independent?
125209
Prove $e^x - e^y \leq e |x-y|$ for $x$ belonging to $[0,1]$