### Questions (23)

 29 Why is $\frac{1}{\frac{1}{0}}$ undefined? 26 Are there any common practices in mathematics to guard against mistakes? 15 How can I calculate $\sin\left(10^{10^{100}} - 10\right)^\circ$? 13 Under what conditions does $x^{\frac{b}{c}} = (x^b)^\frac{1}{c}$ hold? 11 Given two randomly chosen natural numbers, what is the probability that the second is greater than the first?

### Reputation (1,300)

 +5 Are all equiangular odd polygons also equilateral? +10 Use the power-set construction to find a deterministic automata +10 Why does the power rule work? -2 Bijection from finite (closed) segment of real line to whole real line

 64 One question to know if the number is 1, 2 or 3 13 Can someone explain how $\frac{\tan x}{\sec x}=\sin x$? 10 Why does the power rule work? 4 Mutually exclusive countable subsets of a countable set 2 Use the power-set construction to find a deterministic automata

### Tags (35)

 13 trigonometry × 2 6 elementary-set-theory × 4 11 calculus × 3 2 automata 10 exponentiation × 4 2 computer-science 10 intuition 1 probability × 4 10 derivatives 1 limits × 2