rtybase
Reputation
1,052
Top tag
Next privilege 2,000 Rep.
1 6 16
Impact
~10k people reached

 7 Let $a_n=\cos(a_{n-1}), L=[a_1,a_2,…,a_n,…].$ Is there an $a_0$ such that $L$ is dense in$[-1,1]?$ 6 Trigonometric fraction Inequality question 5 How to see $\cos x \leq \exp(-x^2/2)$ on $x \in [0,\pi/2]$? 4 Is $77!$ divisible by $77^7$? 4 Prove $\sum_{i=1}^{n}\frac{a_{i}^{2}}{b_{i}} \geq \frac{(\sum_{i=1}^{n}a_i)^2}{\sum_{i=1}^{n}b_i}$

### Reputation (1,052)

 +10 On the difference between consecutive primes +40 Is $77!$ divisible by $77^7$? +15 If $b^2 \equiv 1 \pmod 3$, is it possible to have $\sigma(b^2) \equiv b^2 \pmod 3$? +15 Trigonometric fraction Inequality question

### Questions (8)

 4 What is the catch in this geometrical/number theory question? 2 Is this function really useless? 2 Prove that for any give sequence of digits, there is a perfect square starting with that sequence 2 Ratio of limits 1 Is there a way to show that $\sqrt{p_{n}} < n$?

### Tags (61)

 18 real-analysis × 11 12 inequality × 4 15 prime-numbers × 12 11 calculus × 8 12 elementary-number-theory × 14 7 algebra-precalculus × 2 12 number-theory × 13 6 trigonometric-series 12 sequences-and-series × 9 6 trigonometry

### Accounts (5)

 Mathematics 1,052 rep 1616 Quantitative Finance 206 rep 25 Area 51 151 rep 1 Raspberry Pi 101 rep 1 Stack Overflow 101 rep 2