Andy

 18 Why is $\frac{1}{\infty } \approx 0$ and $\frac{1}{0} = {\infty}$? 7 What is the importance of Calculus in today's Mathematics? 7 Maclaurin Series of $1/(1-x)$ derived from maclaurin series of $(1+x)^n$ 6 Linearity of the function $f(x) = ax + b$ 6 Cones on surfaces

### Reputation (2,232)

 +10 Cofinality of cardinals +10 What's the cardinality of all sequences with coefficients in an infinite set? +10 Linearity of the function $f(x) = ax + b$ +10 How do I calculate the derivative of matrix?

### Questions (19)

 18 Is the proof of this lemma really necessary? 14 If $A\subseteq\mathbb N$ and $\sum\limits_{a\in A}\frac1a$ converges then $A$ has natural density $0$ 10 What's the cardinality of all sequences with coefficients in an infinite set? 10 Cofinality of cardinals 9 What should be the next step?

### Tags (57)

 18 education × 4 11 general-topology × 7 18 infinity 11 linear-algebra × 5 14 calculus × 12 8 limits × 7 13 sequences-and-series × 5 8 analysis × 4 12 category-theory × 6 7 algebraic-topology × 5

### Bookmarks (29)

 235 Why study Algebraic Geometry? 192 How could we define the factorial of a matrix? 134 $\pi$ in arbitrary metric spaces 56 A bestiary about adjunctions 34 Original works of great mathematician Évariste Galois