# Isaac YIU Math Studio

Hi! I am Isaac and I am come from Hong Kong, China. I am keen on Maths that I have participated a lot of maths competition and have won a lot of awards. The greatest award is that I went to India and participated in INIMC when I was 11. Hong Kong Team got the overall championship! Also, I participated Hong Kong IMO Prelim this year and I got a gold medal. That's about my love of mathematics. If you have some questions about Maths, you can tell me if I can help you. My email is [email protected]

Top Questions

## Prove a trigonometric identity: $\cos^2A+\cos^2B+\cos^2C+2\cos A\cos B\cos C=1$ when $A+B+C=\pi$

asked Sep 10, 2019 at 15:50

## The best $n$-digit password?

asked Sep 9, 2019 at 11:21

## Closed form of $\sum^{\infty}_{n=1} \dfrac{1}{n^a{(n+1)}^a}$ where $a$ is a positive integer

asked Oct 28, 2019 at 5:51

## Find the greatest common divisor of $2^m+1$ and $2^n+1$ that $m,n$ are positive integers.

asked Aug 25, 2019 at 10:20

## Find the sum of the number of all continuous runs of all possible sequences with $2019$ ones and $2019$ zeros

asked Aug 27, 2019 at 9:55