Show that $(0,0)$ is not a local minimum of $f(x,y)=(y-x^2)(y-2x^2)$
39179
Why is $(0, 0)$ not a minimum of $f(x, y) = (y-3x^2)(y-x^2)$?
45432
Showing that $f:(0,2\pi]\to S^1$ is not a homeomorphism
23615
Why does zero derivative imply a function is locally constant?
104263
How to show that $f'(x)<2f(x)$
8851
if $(x_0,y_0)$ is local extrema in $ax^2 + by^2 + cxy + dx + ey + l$ then its global too.
78733
Finding the density for $\min\{X, Y\}$
34325
Minimizing $\sum_{i=1}^n \max(|x_i - x|, |y_i - y|)$ - Sum of Max of Absolute Values
55679
Does there exist a continuous function from [0,1] to R that has uncountably many local maxima?
68617
Show that an entire function that is real only on the real axis has at most one zero, without the argument principle
20192
Prove that: $(f(x))^{2} + (f'(x))^{2} \leqslant \max(a,b)$ where $(a,b) \in \mathbb{R}^2$
109601
Does the equation $\displaystyle min_{x,y} f(x,y)=min_{y}min_{x}f(x,y)=min_{x}min_{y}f(x,y)$ always hold for a minimization problem?
114198
Showing that $y$ is irreducible in $\mathbb R[x,y]/(x^2+y^2-1)$.
31295
$x+y\sqrt{2}$ infimum ($x,y\in \mathbb{Z}$)
36099
Show that $\|f\|^{2}$ attains a minimum value on the interior of $B$
76148
Show that $\exists c \in \mathbb{R} : f(c) = 0$
126259
Minimum of a function on an open interval
24646
Distance between local maximum and local minimum