If $f(x,y)\gt 0$ for any $x,y\in\mathbb R$, then $f(x,y)$ has the minimum?
10585
Does a polynomial that's bounded below have a global minimum?
36099
Show that $\|f\|^{2}$ attains a minimum value on the interior of $B$
1307
Infimum and supremum of the empty set
55461
How to prove that if $a$ belongs to $\mathbb R$, such that $0\leq a \leq\epsilon$, then $a = 0$
144745
Proof of: If $x_0\in \mathbb R^n$ is a point of local minimum of $f$, then $\nabla f(x_0) = 0$.
107727
$m\{x\in [0,1]:f'(x)=0\}>0$
74950
Show a function for which $f(x + y) = f(x) + f(y) $ is continuous at zero if and only if it is continuous on $\mathbb R$
33247
Does $f(0)=0$ and $\left|f^\prime(x)\right|\leq\left|f(x)\right|$ imply $f(x)=0$?
126259
Minimum of a function on an open interval
68409
Consider $f(x,y)=\sup_{θ,φ}\{||e^{i θ }x+ e^{i φ }y||^2: θ,φ∈R\}$ in which $x,y\in\mathbb C^n$
31846
Does $\neg(x > y)$ imply that $y \geq x$?
154247
Proving $f(x)$ attains $\max$ or $\min$ when $f(x)\to0$ as $|x|\to\infty$.
42266
Show that $d(x,y)=\min \{1,|x-y|\}$ is a metric on $\mathbb R$
114844
Global maxima/minima of $f(x,y,z) = x+y+z$ in $A$
58813
Computing $\max_{1/2 \leq x \leq 2} ( \min_{1/3 \leq y \leq 1} f(x,y) )$ where $f(x,y) = x(y \log y - y) - y \log x$.
145919
If $f: \Bbb{R}\rightarrow\Bbb{R}$ is continuous at $0$ and $f(x)=f(2x)$ for each $x\in\Bbb{R}$ then $f$ is constant.
153798
Problem involving maximum and minimum of a continuous function