Pocho la pantera

 7 Is there limit $\lim_{(x,y) \to (0,0)} \frac{x^3}{x^2 + y^2}$? 6 If $(\nabla f(x)-\nabla f(y))\cdot(x-y)\geq m(x-y)\cdot(x-y)$, why is $f$ convex? 5 $(0 \leq f' \leq f$ on $\mathbb R$ and $f(a)=0)$ $\implies f=0$? 5 A difficulty solving a limit 5 Prove $\frac {1}{\cos 0^\circ \cdot \cos 1^\circ} + \ldots +\frac {1}{\cos 88^\circ \cdot \cos 89^\circ}= \frac{\cos 1^\circ}{\sin 1^\circ}$

### Reputation (2,316)

This user has no recent positive reputation changes

### Questions (3)

 9 supremum of $\int |\int f(x)-f(y)\,dy| \,dx$. 1 Convergence of sequence of probabilities (competition problem) 0 behavior of function at infinite

### Tags (62)

 34 calculus × 19 14 multivariable-calculus × 10 24 sequences-and-series × 11 11 analysis × 5 19 ordinary-differential-equations × 25 10 partial-differential-equations × 7 17 real-analysis × 12 9 integration × 8 15 limits × 5 9 induction × 2

### Bookmarks (1)

 0 behavior of function at infinite

### Accounts (4)

 Mathematics 2,316 rep 88 silver badges1717 bronze badges Stack Overflow 101 rep 22 bronze badges Stack Overflow en español 101 rep 11 bronze badge Chess 101 rep 22 bronze badges