# Finn Hulse's Messageboard

Everybody else is doing it, I might as well. Enjoy! :D

Note by Finn Hulse
7 years, 3 months ago

This discussion board is a place to discuss our Daily Challenges and the math and science related to those challenges. Explanations are more than just a solution — they should explain the steps and thinking strategies that you used to obtain the solution. Comments should further the discussion of math and science.

When posting on Brilliant:

• Use the emojis to react to an explanation, whether you're congratulating a job well done , or just really confused .
• Ask specific questions about the challenge or the steps in somebody's explanation. Well-posed questions can add a lot to the discussion, but posting "I don't understand!" doesn't help anyone.
• Try to contribute something new to the discussion, whether it is an extension, generalization or other idea related to the challenge.

MarkdownAppears as
*italics* or _italics_ italics
**bold** or __bold__ bold
- bulleted- list
• bulleted
• list
1. numbered2. list
1. numbered
2. list
Note: you must add a full line of space before and after lists for them to show up correctly
paragraph 1paragraph 2

paragraph 1

paragraph 2

[example link](https://brilliant.org)example link
> This is a quote
This is a quote
    # I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"
# I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"
MathAppears as
Remember to wrap math in $$ ... $$ or $ ... $ to ensure proper formatting.
2 \times 3 $2 \times 3$
2^{34} $2^{34}$
a_{i-1} $a_{i-1}$
\frac{2}{3} $\frac{2}{3}$
\sqrt{2} $\sqrt{2}$
\sum_{i=1}^3 $\sum_{i=1}^3$
\sin \theta $\sin \theta$
\boxed{123} $\boxed{123}$

Sort by:

Does your school have a strange schedule/lots of free periods? You seem to be able to get to a computer at all times of the day, I've been curious how you manage that with school/homework.

Staff - 7 years, 3 months ago

HAHAHAHAHAHAHA! Yes, I have no life, and yes, except today, I spend roughly 2 hours on Brilliant. Which is tough because I'm preparing for a Bar-Mitzvah and I'm swimming. So yeah. I am a Brilliantic for life.

- 7 years, 3 months ago

Nice, it's pretty funny how you said you had no life, my friends tell me that all the time and make fun of me for getting on this website a lot. There all like, " oh ya Robert, your website is only for brilliant people. In a stupid sarcastic tone. Didn't know you were Jewish, that's pretty cool! What's your plan for your Bar-Mitzvah. My friend went to a nice hotel in Mexico and ate a ton of food. He said it was pretty freaking amazing.

- 7 years, 3 months ago

The service is gonna be pretty regular, with a frickin wild party after. For my B'nai-mitzvah, or "good deed", I'm tutoring a bunch of 5th graders about MATHCOUNTS and problem-solving techniques so that they're prepared to be on the MATHCOUNTS team in middle school. It's frickin boss, dude. :D

- 7 years, 3 months ago

Sweet! I also have to ask, have you ever tried science bowl. I'm stuck between doing track, science bowl, or mathcounts . Plus I just found out that for the science and math competitions that my magnet school can't compete in them as a team I was like, " what the **!" Luckily, I heard my other school actually has a decent team. I guess I'll try it next year. Is it only 7th-8th grade. Geez, I have to many unanswered questions.

- 7 years, 3 months ago

No, I've never done Science Bowl. But you should totally do MATHCOUNTS! It's fricking boss! :D

- 7 years, 3 months ago

National Science Bowl (NSB) is something you should really consider doing! It was really fun last year. Do it for the experience.

- 7 years, 3 months ago

How do I get started?

- 7 years, 3 months ago

Science bowl is the best, I first got started in our schools science bowl club, it is really fun and you learn a lof different subects of science ask your teachers about it.

- 7 years, 3 months ago

Oh. My school doesn't have a Science Bowl club. Can I still participate?

- 7 years, 3 months ago

Yeah I think so

- 7 years, 3 months ago

They have nothing like that in Australia. It's saddening.

- 7 years, 3 months ago

I feel sorry for you, but do you have any math competitions, You are 13 years old and you are level 5 in algebra, combinactoris and number theory.Nice!

- 7 years, 3 months ago

I have a couple which I am going to attend and also I am 12.

- 7 years, 3 months ago

That's what I've been thinking as well... then I remembered how blissfully delightful middle school was. Not much homework there.

- 7 years, 3 months ago

HAHAHAHAHA yeah. I haven't done any homework AT HOME since 4th grade. No joke. :D

- 7 years, 3 months ago

Same here I complete my homework at school and then either log on to Brilliant or enjoy

- 7 years, 3 months ago

gosh y'all are so lucky; in Taiwan, we have like 2 hours of homework everyday (as in, at home).... -.- not to mention tests every three or so days.... uggg

- 7 years, 3 months ago

:O

- 7 years, 3 months ago

This is usually what happens in south and south-east Asia. I have done Kindergarten in India, I know (though not that much).

- 7 years, 3 months ago

yup (although, technically, Taiwan is in east asia....)

- 7 years, 3 months ago

I went to the American Embassy School in Dehli. Needless to say, it was luxurious and easy. :D

- 7 years, 3 months ago

..........oh it's the "American Embassy" part eh?

- 7 years, 3 months ago

Hmmm...

- 7 years, 3 months ago

i know it's so sad D:

- 7 years, 3 months ago

Me too

- 7 years, 2 months ago

Dude you're in the US. :P

- 7 years, 2 months ago

What if it's a special sort of school such as a selective school for highly academic or a grammar school.

- 7 years, 2 months ago

He goes to Takoma Park. :P

- 7 years, 2 months ago

no i got MBHS

- 7 years, 1 month ago

Oh. But you used to go to Takoma right?

- 7 years, 1 month ago

yep

- 7 years, 1 month ago

What do you like to do except "Brilling".!

- 7 years, 3 months ago

Math... and friends. Haha, I hadn't thought of Brilling. :D

- 7 years, 3 months ago

What is there to do in Willamsburg?

Staff - 7 years, 3 months ago

Quite a lot! I just don't do any of it. Have you ever heard of Colonial Williamsburg? It was the capital for twice as long as Washington, D. C..

- 7 years, 3 months ago

are you really 13 years old? :D

- 7 years, 3 months ago

Uhh. Well im not ;) (5th grade)

- 7 years, 3 months ago

good! Great going :) hope you guys become renowned for doing something better and new. All the best for Life and its challenges! School is way awesome and Youth is gr8. But when it goes, you know where you stand and I hope, then you know where you want to go next.

- 7 years, 3 months ago

HAHAHAHAHAHAHAH nice. Fist bump for us young people. :D

- 7 years, 3 months ago

:D Youth is beast.

- 7 years, 3 months ago

:D

- 7 years, 3 months ago

Finn Hulse .....hv guts attempt this

- 7 years, 3 months ago

@Finn hulse How/when you noticed you're smart in (math/physics &others...) at the first time ? How did u feel then? :)

- 7 years, 3 months ago

I've always liked math a lot, but when I got to sixth grade, I realized it was cool to be really good at math. So I started becoming "fake"-good, at math just to be cool.

I realized that in fact, math was AWESOME in the summer after sixth grade. Now, I'm in 7th grade, and I do math because of how interesting and amazing it is.

- 7 years, 3 months ago

Hi @Finn Hulse , it seems like you are very eager to be on the "People to Follow", hope you won't want to bite my head off for taking the place, haha. What I want to say is, "People to Follow" isn't a place to get attention, nor judging your achievements/ability. You are doing great and the "People to Follow" doesn't matter very much actually! Keep up your great job, cheers!

- 7 years, 3 months ago

Haha, yes I am very eager to get on that list! I think your head should be pretty safe, though. It's just a matter of pride, for me. You know, like I just want to be considered a person to follow! Don't we all? :D

- 7 years, 3 months ago

You should get an AoPS account.

- 7 years, 3 months ago

I have one, it's FINNN.

- 7 years, 3 months ago

Hey, I am not god! :P

- 7 years, 3 months ago

Dude. I will treat you as such.

- 7 years, 3 months ago

man! finn hulse! u r juss 13 yrs old nd u solve so many problems of higher levels with ease...! gr8! :) salute

- 7 years, 3 months ago

Thanks, you made my day! Actually, I'll be 13 in May. But yeah, I'm totally cool solving problems for fun, but on tests, I freak out and get a lot wrong. :D

- 7 years, 3 months ago

oh ! den u r 12.... den a bigger salute...

- 7 years, 3 months ago

Haha, okay. :D

- 7 years, 3 months ago

Just a salute? I admire you Finn Hulse dude you are awesome. I mean I am 15 and still I can't solve many problems but you , what can I say, FAB. I think this proficiency comes from AoPS. Am I right?

- 7 years, 3 months ago

Hahaha, if you say so.

- 7 years, 3 months ago

Oh actually no, I've never really used AoPS. I can't figure out how to get anywhere. :D

- 7 years, 2 months ago

I also have an AoPS acc but I am confused its so messed up

- 7 years, 2 months ago

Happy (belated) birthday Finn!!! Finally 13 :D I'm turning 13 in twelve more days (May 18)...

- 7 years, 2 months ago

Aww thanks dude! :D

- 7 years, 2 months ago

:) no prob

- 7 years, 2 months ago

Happy (probably belated) birthday, Finn!!!!! You're 13 and a teenager!!! I have 7 more months to wait.

- 7 years, 2 months ago

Lol, I'm almost there (twelve more days!~)

- 7 years, 2 months ago

@Finn Hulse Congrats on your level 4 and level 5 on all subjects especially calculus.

- 7 years, 1 month ago

Oh yeah thanks. As a matter of fact, when I first joined Brilliant (with all Level 2's and 3's and 1's) I was originally Calculus Level 5. There was a really easy problem on the placement test. I accidentally lost it for a while, but then one of my wrong answers to @Sharky Kesa's Level 4 problem turned out to be right after all and my rating got pushed up! :D

- 7 years, 1 month ago

- 7 years, 1 month ago

It was asking for $\zeta(0.5)$ where you had like the sign switched or something.

- 7 years, 1 month ago

Hugh Everett hypothesized that objective reality is actually many worlds, every event being a branch point spawning ever more possible worlds, so that in one world, the cat is alive, and in another, it's dead. Would you be a confirmation of that hypothesis, being that you seem to be everywhere and doing everything all at once?

- 7 years, 1 month ago

That is interesting to think about. And yes, I am doing a lot at once. Yesterday I had my Bar Mitzvah... :O

- 7 years, 1 month ago

Mazel Tov!, to at least one of you anyway.

- 7 years, 1 month ago

Haha thanks. Yes I think roughly $\dfrac{1}{100000}$ of the currently existing universes contain a Finn Hulse who just had a Bar Mitzvah.

- 7 years, 1 month ago

Hi Finn have you noticed that it is showing that you have followed only 51 members. Actually you had followed around 3000+ I suppose?

- 7 years, 3 months ago

Yeah. I thought it was a bug but it wasn't. Did you spend all your time unfollowing people?

- 7 years, 3 months ago

No I didn't . Why would I do that?

- 7 years, 3 months ago

Was talking to Finn. Sorry Ashtik for the miscommunication.

- 7 years, 3 months ago

No! It is a bug! :O

- 7 years, 3 months ago

Yeah it is

- 7 years, 3 months ago

@Sharky Kesa @Trevor B. That was the most freaking boss game of FTW! ever! We have to do that more. :D

- 7 years, 3 months ago

Definitely.

- 7 years, 2 months ago

What's FTW?

- 5 years, 1 month ago

YO FINN!!! For The Win. :D

- 5 years, 1 month ago

Haha... I guess its rhyme time. :D

- 5 years, 1 month ago

Nice name BTW... (I'm talking about the Finn part... The Hulse part is... ok I guess)

- 5 years, 1 month ago

@Daniel Liu @William Cui @Franklyn Wang @Akshaj Kadaveru @Nicky Sun You guys! Good luck at Nationals! I can't wait to watch the CD round on ESPN! It's going to be so intense! Watch out for Colin Tang! :D

- 7 years, 3 months ago

@Dan Lawson Would you mind writing a solution to Plugging Roots into Functions? I'm really interested to see your technique. :D

- 7 years, 2 months ago

@Yan Yau Cheng When will JOMO 4 results be released? I really want to know how @Emery Shelly and I did! :D

- 7 years, 2 months ago

@Calvin Lin Could you boost the rating of Dominoes and Chessboards to like, 2200? It's pretty insanely tough until you realize the trick and then it's (moderately) easy. Good luck solving it! :D

- 7 years, 2 months ago

Is that so? I don't really think it is that hard at all... I will post a solution.

- 7 years, 2 months ago

Oh awesome! :D

- 7 years, 2 months ago

Congratulations @Christopher Boo for beating me in terms of followers! I knew you would eventually, especially since you made "Who to Follow" and I didn't. Well, well, I guess I'll never be as good as you.

- 7 years, 2 months ago

@Peter Taylor I'm happy to see that new bar where you can access solutions! I'm glad I don't need to upgrade to Brilliant Squared to have access to this decent little feature!

- 7 years, 2 months ago

@Peter Taylor With the new solution-viewing format (where you can see what solutions you've posted) I had a "Brilliant" thought. What if when you viewed the page, beside each solution, it showed how many upvotes it had? Also, will you guys make it so we can view everybody's solutions, not just our own?

- 7 years, 2 months ago

@Finn Hulse I found someone who follows more people than you: @Santanu Banerjee

- 7 years, 2 months ago

Yeah, I had noticed that but assumed Finn knew.

- 7 years, 2 months ago

Yeah I did @Daniel Liu but can you find anybody with more comments than me? I'm like the most social person on the site. :D

- 7 years, 2 months ago

There should be a couple.

- 7 years, 2 months ago

I don't think so dude! I haven't seen anybody with like more than 500!

- 7 years, 2 months ago

How about some of the staff? You can't see how many comment they have made.

- 7 years, 2 months ago

Yeah I know that is a problem. :O

- 7 years, 2 months ago

If it was possible they would have millions of comments @Finn Hulse

- 7 years, 2 months ago

@Emil Svensson Do you actually live in Williamsburg VA?

- 7 years, 2 months ago

@Calvin Lin Have you actually received my email? Sorry to bug you, but I'm interested to see your reaction. :O

- 7 years, 2 months ago

@Calvin Lin How is the rating for Plugging Roots into Functions Level 3? Only 16/32 people have solved it which should make it Level 4-5. :/

- 7 years, 2 months ago

Recall that your problem had a wrong answer, and hence had an inflated rating. When we corrected it, the ratings were then pushed down. Given that it simply uses Newton formula, it's definitely not in level 5.

There is a possibility that the numbers are not accurate, given that we had to change the answer.

Staff - 7 years, 2 months ago

I see. But the numbers were unchanged, so I don't think that that would have done anything. Especially considering that the moment you changed the answer, the # of solvers went from 1 to 16. But Newton's Sums is still a Level 4 concept, especially in that application of it. I'd appreciate it if you gave it the correct rating. Thanks. :D

- 7 years, 2 months ago

@Yan Yau Cheng I have a much simpler proof for problem #5.

Question Statement:

Given that $p$ and $p^2 + 8$ are both primes , what is the sum of all possible values of $p$?

Solution:

We can see that if $p \equiv 1$ or $p \equiv 2 \pmod{3}$, then $p^2$ will be congruent to $1$ or $4$ modulo $3$, respectively (which is simply $1^2$ and $2^2$). In both of these cases, by adding $8$ which is $\equiv -1 \pmod{3}$, the expression is $\equiv 0 \pmod{3}$ and is thus never prime (it's divisible by $3$). For $p \equiv 0 \pmod{3}$, the expression is congruent to $0+8 \equiv 2 \pmod{3}$ which may or may not be prime. But because $3$ is the only prime divisible by $3$, we can just plug that in, which is $3^2+8=17$ which is prime. Thus $\boxed{3}$ is the only solution.

- 7 years, 1 month ago

Whew, I'm not very active recently and I just found that you are all most level 5 in every topic! Do you have a great source to learn your physics?

By the way, I like your tag #Finn, added to my list! :P

- 7 years, 1 month ago

Yes! I attribute my recent change mostly to Brilliant Squared, though. Aside from that, @Anish Puthuraya's YouTube channel has been a great resource, along with Khan Academy and a Physics II for Dummies textbook. When I'm unfamiliar with an approach, Google is very helpful, and once I master a formula, I can apply it!

Oh yeah but also the thing about Brilliant Squared is that the problems are ranked way higher than they should be. I think it's mostly because the staff can choose the rating, even though in reality it gets pushed down a ton.

Oh yeah and #Finn is a pretty epic tag. :D

- 7 years, 1 month ago

Thanks! :D

- 7 years, 1 month ago

I added that tag the moment I realized you could add any tag to your homepage. :D

- 7 years, 1 month ago

My mom speaks Mandarin and I was wondering how you pronounce your last name, since I don't think it's in pinyin.

- 7 years, 1 month ago

- 7 years, 1 month ago

Oh. My name is Yuxuan (Yû Xuān) and Seah is my family name. In pinyin it's Shé. I don't really know how to tell you how to pronounce it in English, because when people first see it, they usually get it wrong and I just adopt a Trial and Error method to help them get it right. But I could try :D

'See-ahh.' That's somewhat right. (My Chinese name, in case you wanna know, is 佘宇轩.) :D Try to teach yourself mandarin. It's fun. And educational. :D

- 7 years, 1 month ago

Sorry about the formatting though, for the 'û' the sign on top is actually inverted. (Couldn't get it right on my computer. D:) And yes, 'Seah' isn't in pinyin. o.O Interesting that you ask such a question. :D

I didn't know your mom speaks Mandarin! Hmm... is she from China? Or Singapore? :D

- 7 years, 1 month ago

Well, names are complicated. Check this out: http://en.wikipedia.org/wiki/Wolfe+585,_Senior

- 7 years, 1 month ago

Aww Finn, did'cha unfollow me? D: and what happened to Theme based problems. And hows the country ur in XP

- 7 years ago

He hasn't left the country, I think, but the state. I am in a different country, SINGAPORE! :D

- 7 years ago

COME VISIT RI XD even tho im not sure if they allow strangers in

- 7 years ago

I don't think I can. Go to the Science building in Jurong East tomorrow, you might see me in the afternoon.

- 7 years ago

Hi Finn, did you take any math lessons outside the school? (i.e KUMON)

- 6 years, 4 months ago

Yes, a senior from the local college that my parents teach at comes over once a week to tutor me in advanced graduate-level math.

- 6 years, 4 months ago

Dude, you came back! Where have you been?

- 6 years, 4 months ago

That sounds really neat and fun, did your school has some kind of program that teaches you in math too? And how many times did you practice in a week? Sorry for asking too many questions, I'm just too curious ><

- 6 years, 4 months ago

Hi

Will you post a question anytime soon ?

- 6 years, 4 months ago

Sure!

- 6 years, 4 months ago

@Mardokay Mosazghi Dude, I loved this problem Super Finn to the Rescue. And yes, I love trampoline tricks. :D

- 7 years, 3 months ago

@Finn Hulse Thanks

- 7 years, 3 months ago

@Calvin Lin Have you seen this epic problem!? I think it's really cool and takes advantage of one of the coolest algebraic principles that I know! You'll enjoy it! :D

- 7 years, 3 months ago

Several edits are needed.

1) $g(x)$ is a polynomial, otherwise I can define $|g(3) |$ to be anything.
2) The degree of $g(x)$ matters, otherwise we can take the square.
3) The leading coefficient of $g(x)$ matters, otherwise we can just multiply by 2.

Staff - 7 years, 3 months ago

Okay. Wow. Dang, you're good. :O

- 7 years, 3 months ago

What do you mean the degree of $g(x)$ matters?

- 7 years, 3 months ago

The polynomial $g(x) = (5(3)^5+3(3)^4-11(3)^3-2(3)^2+3(3)+5) ^2$ will also satisfy your conditions as previously stated, namely that each of the roots of $g(x)$ is the reciprocal of one of $f(x)$ roots.

Note that currently, saying "the coefficient of $x^5$ is -5 is also not sufficient, since I could take $g(x) = A(5(3)^5+3(3)^4-11(3)^3-2(3)^2+3(3)+5) ^2$ for some suitable constant $A$.

Note that you will also need the condition that "each of $f(x)$ roots are the reciprocal of $g(x)$ roots", otherwise, I can just take $\alpha x - 1$, where $f( \alpha ) = 0$.

The issue with some of your problems is that they are not correctly and clearly phrased. You have an idea of what it is in your head, but when written down, it could be interpreted in a multitude of ways. You need to take care of such 'edge cases' that I listed out above, instead of expecting others to deduce what you are thinking. They will not do so, and would instead just skip your problem.

Staff - 7 years, 3 months ago

It's all Greek to me. Would you mind making the changes? I'm sorry for the inconveniences with all of these problems. I'll make sure to not make such silly mistakes in the future. :D

- 7 years, 3 months ago

I've made some changes which makes $g(x)$ uniquely determined (up to sign). There are possibly better ways of expressing it that are not so clunky.

I avoided talking about the "content of the polynomial", as that is not a commonly understood term.

Staff - 7 years, 3 months ago

Finn, can you please tell me what is the line between 10 and Euler's totient function in your problem "Let's compute this manually " in your " Modular arithmetic and NT problems " set ?

- 7 years ago

$a|b$ means that $a$ is divisible by $b$.

- 7 years ago

thank you ....

- 7 years ago

No it means the opposite. So like $3 \mid 12$.

- 7 years ago

LOL, fail! Could be used in the thing.

- 7 years ago