Calvin Lin
Reputation
31,843
79/100 score
3 35 98
Impact
~285k people reached

 64 Is there any branch of Mathematics which has no applications in any other field or in real world? 37 Prove that none of $\{11, 111, 1111,\dots \}$ is the perfect square of an integer 29 Calculate $\underset{x\rightarrow7}{\lim}\frac{\sqrt{x+2}-\sqrt[3]{x+20}}{\sqrt[4]{x+9}-2}$ 28 Surprising identities / equations 28 Is the number $0.112358132134…$ rational or irrational?

### Reputation (31,843)

 +10 Finding the equation of a plane. +10 Lowest multiple with given condition +10 Does $\lambda_1^n+ \lambda_2^n+ \dots +\lambda_k^n =0$ for all $n$ imply that $\lambda_1= \lambda_2= \dots= \lambda_k = 0$? +10 Prove that none of $\{11, 111, 1111,\dots \}$ is the perfect square of an integer

### Questions (14)

 180 Surprising identities / equations 27 When is $2^n \pm 1$ a perfect power 20 Odd perfect squares whose decimal representation consist only of 1's and o's 18 For polynomial $f$, does $f$(rational) = rational$^2$ always imply that $f(x) = g(x)^2$? 16 Comparing sums of surds without any aids

### Tags (244)

 420 elementary-number-theory × 113 198 geometry × 112 274 combinatorics × 120 149 real-analysis × 47 256 algebra-precalculus × 70 146 contest-math × 55 230 number-theory × 81 142 sequences-and-series × 43 207 inequality × 72 134 linear-algebra × 58

### Accounts (2)

 Mathematics 31,843 rep 33598 Area 51 151 rep