Emps-World Forum

Miscellaneous => Off-Topic => Topic started by: Chazz on December 12, 2014, 02:13:20 am

Title: Math Questions
Post by: Chazz on December 12, 2014, 02:13:20 am
eyy, got questions, ask em. If you have Questions instead, look at Vaughn147523's Topic (http://emps-world.net/forum/index.php?topic=3908.0).


I'll prolly give out random Math questions every now and then for fun. With ing prizes ofc (soon, for complex questions).

Please only use YOUR brain to answer, unless I specify you're allowed a calculator on a specific problem. It's easy to check if you're legit cuz I'll ask for an explanation. Feel free to look up topics, but not the question itself. Cuz you won't find em :kappa:


New problemo

Since u guys r boring and don't like challenges, no big prize on this one q_q

(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fpuu.sh%2FhJ5Sa%2Fd09fe23a59.png&hash=596439b34db7ed7970fe98b70e9f5e2d)

lets make it 2 for the helluvit

(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fpuu.sh%2FhJ5Xv%2F38659d4458.png&hash=bca288e017925d8015edd980dcacb831)

Archive (https://docs.google.com/spreadsheets/d/1CrC0qpDCnSFLjlPIID0s2AsHyM7-tyIv0K4pF6VgW0c/edit?usp=sharing)
Title: Re: Math Questions
Post by: Nany499 on December 12, 2014, 10:51:15 am
Please only use YOUR brain to answer, unless I specify you're allowed a calculator on a specific problem.

WHY, JUST WHY IS THIS RULE HERE? I'm always too lazy to calculate stuff by myself so I always use a calculator, chazz pls
Title: Re: Math Questions
Post by: Hmm2 on December 12, 2014, 12:32:34 pm
i hate you.. you made me do some math
but anyway the answer is x=3.5
i need to write this on the pc to take a screenshot so i'll post the way later  because idk how to do math on computer progarmms so it is going to take me some time ;)

edit: sorry i had to re-upload it because there were some mistakes. and sorry for the bad writing, it is hard to write using a pin and a pad for laptop :)
(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fi62.tinypic.com%2F1zwojgj.png&hash=8c36299752c95e76236bd9ae775bc189)
Title: Re: Math Questions
Post by: Fireblast12 on December 12, 2014, 01:42:26 pm
i hate you.. you made me do some math
but anyway the answer is x=3.5
i need to write this on the pc to take a screenshot so i'll post the way later  because idk how to do math on computer progarmms so it is going to take me some time ;)

edit: sorry i had to re-upload it because there were some mistakes. and sorry for the bad writing, it is hard to write using a pin and a pad for laptop :)
(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fi62.tinypic.com%2F1zwojgj.png&hash=8c36299752c95e76236bd9ae775bc189)
Why did I discover this topic just now :(
You were fastah than me :(
Title: Re: Math Questions
Post by: Chazz on December 12, 2014, 09:14:21 pm
Nice going, Hmm2. I'll get the next one up shortly.

It's up.
Title: Re: Math Questions
Post by: Chazz on December 15, 2014, 03:47:30 am
You guys SUCK at vectors.

All you have to do is transform the equations to their vectors, dot product all of them, and find which pair's dot product is equal to zero (making them orthogonal, otherwise known as 90 degrees from eachother).

Answer is d, because
i= <3,-1,5>
iv=<1,-7,-2>
3(1)+-1(-7)+5(-2)=0

Easy.

Next question coming up soon. With a prize this time.

ITS UP. PRIZE=1M
Title: Re: Math Questions
Post by: Ahrim Ghost on December 15, 2014, 05:03:20 am
Well here's my answer,

Answer = D ( NOTA) , because the answer is equal to    "-∞"

My working out. ( Sorry it's messy )

(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fi58.tinypic.com%2F2e1avdg.jpg&hash=a1dd54edd9532f1082fe83a7c743e8f9)
Title: Re: Math Questions
Post by: Chazz on December 15, 2014, 05:12:11 am
You have the right idea of trying to break up the log and go from there.. but you took a step that made it a bit complicated: turning ln(n!/n^n) to ln(n1!)-ln(n^n). There's a better split you can make, which eventually results in Integration solving it.

With your current answer, since you didn't 'prove' lim n->inf  of ln(n!)/n - ln(n)= -infinity, I can't accept that as an answer.
*The answer isn't negative infinity either, so don't try to keep justifying this :S
Keep trying :)
Title: Re: Math Questions
Post by: Chazz on April 08, 2015, 01:40:34 am
Bringing this back cuz I'm bored and rich

New question:

(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FVvB0nCf.png&hash=dee219403ca288458bfc10be74675a42)

Winner gets 1m
show work/reasoning
Title: Re: Math Questions
Post by: Nany499 on April 08, 2015, 09:39:07 pm
The answer is D) and that's why: (I know my handwriting is horrendous, but I hope it's understandable)

(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fi57.tinypic.com%2F23j0j74.jpg&hash=213e0338f2cebc2dbba249251c19c13b)

Title: Re: Math Questions
Post by: Chazz on April 08, 2015, 09:54:10 pm
You guys have till April 10 to submit an answer with explanation. Then, the first submission with a correct response and sufficient reasoning will   be granted the prize.

This problem can be solved without calculus, for those confused by the derivative in the above solution^
You can submit multiple attempts if you wish.
In the event of no correct response, I will grant 1 additional day with a false answer choice that has been achieved eliminated.

GL
Title: Re: Math Questions
Post by: Irfox on April 08, 2015, 09:57:54 pm
I'm glad that there are people alive that understand this stuff.

You guys SUCK at vectors.

All you have to do is transform the equations to their vectors, dot product all of them, and find which pair's dot product is equal to zero (making them orthogonal, otherwise known as 90 degrees from eachother).



Uwot
Title: Re: Math Questions
Post by: Nany499 on April 08, 2015, 10:33:03 pm
You guys have till April 10 to submit an answer with explanation. Then, the first submission with a correct response and sufficient reasoning will   be granted the prize.

This problem can be solved without calculus, for those confused by the derivative in the above solution^
You can submit multiple attempts if you wish.
In the event of no correct response, I will grant 1 additional day with a false answer choice that has been achieved eliminated.

GL

does that mean what I did was wrong or is there just insufficient information on what I did?
EDIT:I am an idiot and have no idea how to add numbers, the proper solution will be added shortly( I did this both in terms of x and y and it worked so pls be right)
so it's actually 50 because: (I basically rewrote it with the correct numbers)
(first line the =10-y is supposed to be =>10-y sorry I was writing pretty quickly)

(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fi60.tinypic.com%2F214w7qx.jpg&hash=f88220fd9ba6ad35c23a790feb1c5e68)
Title: Re: Math Questions
Post by: Suryoyo K0 on April 09, 2015, 09:22:25 am
I'm glad that there are people alive that understand this stuff.
Show us the almighty Irfan brain :kappa:
Title: Re: Math Questions
Post by: Joshiee on April 09, 2015, 11:41:55 am
It's an 0 from me.
Title: Re: Math Questions
Post by: Chazz on April 09, 2015, 10:12:37 pm
Dank job by Nany499

Instead of going for the the derivative, you could use the formula for the vertex of a quadratic in the form ax2+bx+c which is (-b/2a, f(-b/2a)) (derived from the derivative)

If you see me logged in game/on forums, message me and ask for your prize.

New one will be up soon.
Title: Re: Math Questions
Post by: Nany499 on April 10, 2015, 03:43:32 pm
Dank job by Nany499

Instead of going for the the derivative, you could use the formula for the vertex of a quadratic in the form ax2+bx+c which is (-b/2a, f(-b/2a)) (derived from the derivative)

If you see me logged in game/on forums, message me and ask for your prize.

New one will be up soon.

I actually did not know you could do it like that but seems like it's waaaay more convenient than differentiating so I'll try it out next time, also I don't really want the money I don't play ingame anymore I just enjoy doing math now and again so don't worry I'll try to answer your next question aswell :)
(ofcourse it'd be no fun if I was the only guy actually participating in this)
Title: Re: Math Questions
Post by: Chazz on April 11, 2015, 04:20:22 am
Here it is
(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fpuu.sh%2Fh9q0I%2F1e11d73b64.png&hash=5902124062c9223df4e7878a6bbcc294)
Title: Re: Math Questions
Post by: Chazz on April 13, 2015, 10:21:29 pm
ay guise r we ded alredy? Literally free 2m waiting to be taken
If you're leaning towards non-calculus questions, please let me know.
Title: Re: Math Questions
Post by: Nany499 on April 14, 2015, 09:26:41 am
ay guise r we ded alredy? Literally free 2m waiting to be taken
If you're leaning towards non-calculus questions, please let me know.

I've been meaning to solve it but I'm just too lazy to do all the integration. Calculus is my favourite subject, however some vectors would be nice since I have an exam on vectors in a few days and a bit of practice'll be good
edit: I've also noticed that I'm the only one participating in this so I decided to take my time doing it
edit 2:keep that question I'll solve it either today or tomorrow
Title: Re: Math Questions
Post by: Vaughn147523 on May 10, 2015, 01:43:18 am
I believe that Calculus questions aren't really doing no good on the topic :P.

I'd like to offer a question of my own though, if I may, to get the brain going;

(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FJ4IoJFj.jpg&hash=dfe004cb9d9395d4e902fd5b2dd7c659)
Title: Re: Math Questions
Post by: Il Skill L on May 10, 2015, 09:50:23 am
I believe that Calculus questions aren't really doing no good on the topic :P.

I'd like to offer a question of my own though, if I may, to get the brain going;

(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FJ4IoJFj.jpg&hash=dfe004cb9d9395d4e902fd5b2dd7c659)
64/75 ?
Title: Re: Math Questions
Post by: Vaughn147523 on May 10, 2015, 04:06:29 pm
I believe that Calculus questions aren't really doing no good on the topic :P.

I'd like to offer a question of my own though, if I may, to get the brain going;

(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FJ4IoJFj.jpg&hash=dfe004cb9d9395d4e902fd5b2dd7c659)
64/75 ?
May I ask how you got that? :P
Title: Re: Math Questions
Post by: C4 Nerd on May 10, 2015, 04:48:01 pm
I believe that Calculus questions aren't really doing no good on the topic :P.

I'd like to offer a question of my own though, if I may, to get the brain going;

(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FJ4IoJFj.jpg&hash=dfe004cb9d9395d4e902fd5b2dd7c659)

(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FGLNCdDP.jpg&hash=a2842dbe7e0a505729881b1c4bbf1372) 64/125? xD
Title: Re: Math Questions
Post by: Vaughn147523 on May 10, 2015, 05:08:47 pm
I believe that Calculus questions aren't really doing no good on the topic :P.

I'd like to offer a question of my own though, if I may, to get the brain going;

(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FJ4IoJFj.jpg&hash=dfe004cb9d9395d4e902fd5b2dd7c659)

(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FGLNCdDP.jpg&hash=a2842dbe7e0a505729881b1c4bbf1372) 64/125? xD
Looks good to me! Here's how I did it:

(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2Fl3IeoGO.png&hash=886120e4450071952c1da828fb63e0df)

I'll let Chazz give another question now since this is his topic, that was just a warm up.
Title: Re: Math Questions
Post by: M3an123 on May 10, 2015, 06:08:55 pm
Paint skills :o

I got a problem with maths to be honest and I really do want to give some of the questions I couldn't solve but maths language in English is way too complicated to me as well as for google translator lol

I'll try my best translating them out and oh well, you guys might could gimme a hand :)
Title: Re: Math Questions
Post by: Vaughn147523 on May 10, 2015, 06:16:41 pm
Paint skills :o

I got a problem with maths to be honest and I really do want to give some of the questions I couldn't solve but maths language in English is way too complicated to me as well as for google translator lol

I'll try my best translating them out and oh well, you guys might could gimme a hand :)
https://emps-world.net/forum/index.php?topic=3908.0

I would post them there then. Feel free to bring it back up, we are in off topic afterall so no harm will be done to your account.
Title: Re: Math Questions
Post by: Il Skill L on May 10, 2015, 06:30:48 pm
Lmao, i failed with 5^3 ;_;

Should have written it down on the paper tho
Title: Re: Math Questions
Post by: Pure Ranged1 on May 10, 2015, 06:31:16 pm
You could also do it by this exponentiation rule which I find much easier;
(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fupload.wikimedia.org%2Fmath%2F4%2F0%2F8%2F408d74901aff3a344972e27152fed217.png&hash=d290c0106b395589ca06680be4852c78)
Paint skills :o

I got a problem with maths to be honest and I really do want to give some of the questions I couldn't solve but maths language in English is way too complicated to me as well as for google translator lol

I'll try my best translating them out and oh well, you guys might could gimme a hand :)
^^ Same problem.

More not complicated math questions ples. (A lot of stuff going on here I haven't learned yet lel)
Title: Re: Math Questions
Post by: Nany499 on May 10, 2015, 06:45:02 pm
Here it is
(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fpuu.sh%2Fh9q0I%2F1e11d73b64.png&hash=5902124062c9223df4e7878a6bbcc294)
before we go on though, could you explain how we do this, since I tried a few methods, but all failed
Title: Re: Math Questions
Post by: Chazz on May 10, 2015, 11:43:19 pm
Here it is
(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fpuu.sh%2Fh9q0I%2F1e11d73b64.png&hash=5902124062c9223df4e7878a6bbcc294)
before we go on though, could you explain how we do this, since I tried a few methods, but all failed
Gladly ^^

It's been so long I can't find my original solution typed up in LaTeX ;_;

Anyway, utilizing the fact that 1/cos=sec, every term now has a sec factored in. So you have
Integral -1 to 1 of x2011*sec(x) + sec(x)tan(x) + sec(x)

Using even/odd identities, that an odd function times an even function results in an odd function, and seeing that x2011 is odd while sec(x) is even, we know that their product is odd. Thus the integral from -a to a of this product will always be zero.

The second part simply evaluates to sec(x)

The third part is ln(sec(x)+tan(x)) (Not gonna prove it here, just look up integral of sec(x))

And finally evaluating this result at the bounds, we get
sec(1) + ln(sec(1)+tan(1)) - sec(-1) - ln(sec(-1)+tan(-1))

Again, even/odd tells us for even (sec), f(-x)=f(x) and for odd(tan) f(-x)=-f(x)
So this is equal to

sec(1)+ln(sec(1)+tan(1)) - sec(1) - ln(sec(1)-tan(1))

Secants cancel and you're left with the logs. Using log rules, log(a) - log(b)= log(a/b), combine the two and you end up with

ln((sec2(1)-tan2(1))/(sec-tan)2)

Top goes to -1. Flip the 2 power to -2 and bring it up. Use log rules to bring down exponent as coefficient. Combine sec(1)-tan(1) using only cos and sin into -(cos(1))/(sin(1)-1). Negate the negative with the -1 we got earlier. Using the negative from the coefficient of the log, flip the inside fraction of the log (log rules), and you get Option B

I guess it was a little more work than I promised.. haha...
Title: Re: Math Questions
Post by: Chazz on May 11, 2015, 05:48:30 am
New problemo

Since u guys r boring and don't like challenges, no big prize on this one q_q

(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fpuu.sh%2FhJ5Sa%2Fd09fe23a59.png&hash=596439b34db7ed7970fe98b70e9f5e2d)

lets make it 2 for the helluvit

(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fpuu.sh%2FhJ5Xv%2F38659d4458.png&hash=bca288e017925d8015edd980dcacb831)
Title: Re: Math Questions
Post by: Vaughn147523 on May 13, 2015, 07:33:23 pm
Any attempt yet? Already got the answers :D.
Title: Re: Math Questions
Post by: Yaz on May 13, 2015, 07:35:52 pm
Any attempt yet? Already got the answers :D.
Those questions are some next level ****

Easier pls :s
Title: Re: Math Questions
Post by: Range 4 Meee on May 13, 2015, 07:50:38 pm
Any attempt yet? Already got the answers :D.
Those questions are some next level ****

Easier pls :s
(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FXWaJizy.png&hash=304f95593ff313f45814d1d83d5c153b)
#Old, I know
Title: Re: Math Questions
Post by: Yaz on May 13, 2015, 07:52:05 pm
Any attempt yet? Already got the answers :D.
Those questions are some next level ****

Easier pls :s
(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FXWaJizy.png&hash=304f95593ff313f45814d1d83d5c153b)
#Old, I know
old for u. new to me 19 hhhh
Title: Re: Math Questions
Post by: Someone12116 on May 13, 2015, 08:02:44 pm
x=x

I win!
Title: Re: Math Questions
Post by: Chazz on May 13, 2015, 08:45:14 pm
Any attempt yet? Already got the answers :D.
Those questions are some next level ****

Easier pls :s
hint: try to get both equalities to the form a^(something)=a^(somethingelse), and that the log base a of both sides. This should leave you with a system of equations that can easily be solved.
Another hint: this can be done by changing for example 27 to 33, and subsequently using power rules to factor the 3 into the current exponent.
Title: Re: Math Questions
Post by: Suryoyo K0 on May 14, 2015, 12:37:28 am
Any attempt yet? Already got the answers :D.
Those questions are some next level ****

Easier pls :s
hint: try to get both equalities to the form a^(something)=a^(somethingelse), and that the log base a of both sides. This should leave you with a system of equations that can easily be solved.
Another hint: this can be done by changing for example 27 to 33, and subsequently using power rules to factor the 3 into the current exponent.
because that totally made it easier for him :kappa:
Title: Re: Math Questions
Post by: Nany499 on May 14, 2015, 08:32:50 am
Any attempt yet? Already got the answers :D.
Those questions are some next level ****

Easier pls :s
hint: try to get both equalities to the form a^(something)=a^(somethingelse), and that the log base a of both sides. This should leave you with a system of equations that can easily be solved.
Another hint: this can be done by changing for example 27 to 33, and subsequently using power rules to factor the 3 into the current exponent.

You haven't added my previous answer to the archive btw  >:( >:( >:( >:( >:(
('ll try to solve the latest questions soon-ish)
(also since I do math in german I'll have to read a bit on what constant terms of expansion are cuz languages)
edit:this took longer than expected because I am a moron who forgot how exponents work, but I hope I made no mistakes
this time:

(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fi59.tinypic.com%2Ffdybsp.jpg&hash=49ffd88ce92e029c47d8329ab7137014)

Title: Re: Math Questions
Post by: Chazz on May 14, 2015, 08:12:40 pm
Any attempt yet? Already got the answers :D.
Those questions are some next level ****

Easier pls :s
hint: try to get both equalities to the form a^(something)=a^(somethingelse), and that the log base a of both sides. This should leave you with a system of equations that can easily be solved.
Another hint: this can be done by changing for example 27 to 33, and subsequently using power rules to factor the 3 into the current exponent.

You haven't added my previous answer to the archive btw  >:( >:( >:( >:( >:(
('ll try to solve the latest questions soon-ish)
(also since I do math in german I'll have to read a bit on what constant terms of expansion are cuz languages)
edit:this took longer than expected because I am a moron who forgot how exponents work, but I hope I made no mistakes
this time:

pic

Close. you error is in calculating x after you find y.
Title: Re: Math Questions
Post by: Nany499 on May 15, 2015, 08:44:58 am
Yep, I always do mistakes like that, even in exams, is the answer 24? since if y=6 and x=3y+3 then x=3*6+3=21 and then 2*21-3*6=24

edit: I even fixed it in my text book

(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fi61.tinypic.com%2F2qs7ax2.jpg&hash=042a510c0d45b6fb6fa37798359db0b9)

Title: Re: Math Questions
Post by: Pure Ranged1 on May 15, 2015, 10:53:05 am
I have learned this subject 1 year ago, it took me sometime to remember how to do such stuff ;p
Nany has beaten me, but I had fun solving it anyway :)

(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FpYxp7PA.jpg&hash=1828f6f3df93d7f0854d7792d8165746)
(if there's anything not clear, ask me about it)
Title: Re: Math Questions
Post by: Chazz on May 15, 2015, 04:27:27 pm
Yep, I always do mistakes like that, even in exams, is the answer 24? since if y=6 and x=3y+3 then x=3*6+3=21 and then 2*21-3*6=24

edit: I even fixed it in my text book

pic

Congratz.
Now for the second part :^)

(https://emps-world.net/forum/proxy.php?request=http%3A%2F%2Fpuu.sh%2FhJ5Xv%2F38659d4458.png&hash=bca288e017925d8015edd980dcacb831)