#help-36

1 messages · Page 194 of 1

ivory bear
#

yes maybe ill try your ques man

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but idk mate

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monday i have a school test too

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so maybe ill leave in middle

valid carbon
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lmao how do we have freaking jiya as a mutual

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small world

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never noticed before

ivory bear
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i too noticed that fact long before

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ig you were in r/jnt and left it

valid carbon
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jeeneetards? opencry

vague anchor
valid carbon
ivory bear
vague anchor
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yes

valid carbon
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i was wondering if you were a irl friend or smth

ivory bear
valid carbon
#

thatd be very small world

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anyway

ivory bear
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@vague anchor .

valid carbon
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i hate this question

ivory bear
vague anchor
#

im on laptop, isnt it zoomable

valid carbon
ivory bear
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the e^stuff isnt visible

ivory bear
valid carbon
ivory bear
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tu bhi india se?

ivory bear
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mb.

valid carbon
vague anchor
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2sin^2 x on RHS at numerator

valid carbon
vague anchor
#

2

ivory bear
soft zealotBOT
#
percykel's Avatar

Click here to view the image.

ivory bear
#

but i asked you too about it but you told thailand or some other country

valid carbon
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its fan art of thanatos

ivory bear
valid carbon
#

the greek god of non-violent death

valid carbon
vague anchor
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IG I pingged to early😓 😓

ivory bear
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delete it

valid carbon
#

!nosols

final saddleBOT
#

As a helper, please do not give out answers that could be copied as a homework solution. Have the student work through the problem themselves and guide them along the way.

vague anchor
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when did i say it as answer

ivory bear
#

saala no soln chep dete

valid carbon
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or stick to jnt

ivory bear
#

school test spree

vague anchor
#

i have answer

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what i want is method and solution approach
nosols thop detae ho saalo

valid carbon
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yeah so

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!nosols

final saddleBOT
#

As a helper, please do not give out answers that could be copied as a homework solution. Have the student work through the problem themselves and guide them along the way.

valid carbon
#

nobody is gonna give you the solution

vague anchor
valid carbon
#

i mean i dunno these people might

ivory bear
valid carbon
#

maybe its an ego trip for them

ivory bear
#

chodo usko wo anime fan lagra door se

vague anchor
#

then?

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ik

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but help me find max value of RHS only

valid carbon
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ok

vague anchor
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that is the topic headed with

valid carbon
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either you stop or im mod pinging

we also have the insane amount of shade thrown towards me for no reason

vague anchor
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pls

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no abuse @terse sorrel

valid carbon
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<@&268886789983436800> see

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indeed

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also its greek

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thanks roketto

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@vague anchor id suggest closing this and reposting while telling us what you've already tried

bold turtle
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Hard agree on this; this actually should be restarted anew

valid carbon
vague anchor
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<@&268886789983436800>
can u also take action on this guy who was yapping here nepou or whatever

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.close

final saddleBOT
#
Channel closed

Closed by @vague anchor

Use .reopen if this was a mistake.

vague anchor
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.close

opaque ember
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wot

valid carbon
tired walrus
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tf happened over here

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that was one trainwreck of a convo

bold turtle
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It was a train that lost its engine

valid carbon
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you guys cant even follow half of it cuz its hindi

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but yeah

bold turtle
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oh I can and it's still a trainwreck

valid carbon
vague anchor
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😭

tired walrus
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i couldnt follow half of it cause this guy literally asked me to block him so he can't DM me anymore

vague anchor
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now u might unblock me
i have got control on my senses

valid carbon
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.reopen because this is hilarious

final saddleBOT
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✅

vague anchor
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why in this world was it reopenedđŸ˜”â€đŸ’«

vague anchor
old quarry
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u can close it again

vague anchor
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im not gonna its none of my duty now

vague anchor
old quarry
#

nah u can do what u want

vague anchor
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still i dont wanna make trash of this server
mathsđŸ„č

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.close

final saddleBOT
#
Channel closed

Closed by @vague anchor

Use .reopen if this was a mistake.

bold turtle
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For the record - the only people who can close channels are the person who opened the channel to begin with and anyone with at least a Helpful* role or greater

bold turtle
#

This has been noted, no need to keep this train off its tracks.

old quarry
#

🚋

final saddleBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
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‱ Show your work, and if possible, explain where you are stuck.
‱ After 15 minutes, feel free to ping <@&286206848099549185>.
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Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

round cedar
final saddleBOT
round cedar
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hey hru, i wanted to prove that the red brackets diverges so i did those steps

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is that ok?

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btw ive shown that the red brackets is >0 for every n which is natural

tired walrus
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0*e^∞ = e^∞ thonkthonk

round cedar
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hru btw

tired walrus
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btw was this limit given to you \textbf{exactly} in the form $\frac{\frac1n - e^{-n^2}}{\frac1n}$ or did you mess with it in any way

soft zealotBOT
round cedar
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no i wanted to show that the red brackets diverges (cuz ive came to a conclusion it is since 1/n diverges and e^-n^2 converges)

tired walrus
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ok gonna ask for the original then

round cedar
round cedar
tired walrus
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i really think you're on a road to completely confuse yourself (partly because even i am confused)

round cedar
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lol

round cedar
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i was needed to prove this one converges but not aboslutely converges

tired walrus
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erase the "was"

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but yes ok

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the most straightforward way is in fact to break it into the sum of two series

round cedar
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"conditionally convergent series"

tired walrus
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$\sum_{n=1}^{\infty} \frac{(-1)^n}{n} - \sum_{n=1}^{\infty} (-1)^n e^{-n^2}$

soft zealotBOT
tired walrus
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which you can analyze with about 97% less headache as: $$\underbrace{\sum_{n=1}^{\infty} \frac{(-1)^n}{n}}{\text{cond. conv.}} - \underbrace{\sum{n=1}^{\infty} (-1)^n e^{-n^2}}_{\text{abs. conv.}}$$

soft zealotBOT
round cedar
tired walrus
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proving that it converges (without specifying cond. or abs.) is straightforward

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from then you need to show that it fails to converge absolutely.

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it will be best to do this abstractly, unless that's considered non-kosher in your class

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meaning that you prove the more general result

tired walrus
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if $\sum_{n=1}^{\infty} c_n$ converges conditionally and $\sum_{n=1}^{\infty} a_n$ converges absolutely, then $\sum_{n=1}^{\infty} (c_n + a_n)$ converges conditionally.

soft zealotBOT
tired walrus
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the choice of names is deliberate on my part

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this can be done with some funny business involving the triangle inequality

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which i think would be $|c_n + a_n| \geq |c_n| - |a_n|$ or something like this

soft zealotBOT
round cedar
# soft zealot **Ann**

wish we had a thorem like this which we could use, but as you say i need to prove its converges & not abs converges --> then it cond converges

tired walrus
final saddleBOT
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@round cedar Has your question been resolved?

round cedar
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@tired walrus is that ok to prove red series abs converges ? so then it converges

tired walrus
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i can't read hebrew so i can't follow the logic.

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but im p sure the limit of the ratio of adjacent terms is 0 not 1.

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even better for you, but you have to not lie in your proof.

tired walrus
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what is this symbol

round cedar
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if p<1 then it converges

tired walrus
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... maybe you mean rho?

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but if it's a greek letter, you drew it in such a wonky manner that it looks like phi instead.

round cedar
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i googled it

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rn

round cedar
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@tired walrus used to chatgpt to translate what i have written

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not the best translation but does the job

tired walrus
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ok yeah that will do

round cedar
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.close

final saddleBOT
#
Channel closed

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final saddleBOT
#
Available help channel!

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Remember:
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clear rivet
final saddleBOT
bold zenith
#

!status

final saddleBOT
#
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
bold zenith
#

Also, do you have a diagram/sketch? If not, draw one and post a photo of it.

robust mulch
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where is this question from?

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looks like an imo q

clear rivet
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egmo 2

robust mulch
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ohh

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cool

clear rivet
bold zenith
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Top tip: Make sure to make your sketches big

clear rivet
#

anybody know how to solve

bold zenith
#

I don’t actually I suck at geometry but I hope another helper can use what you’ve posted so far

clear rivet
#

alexis man plzzz

bold zenith
#

You can ping helpers role after 15 mins of posting

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Not yet

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It’s a high traffic time with like a few helpers and I don’t know geometry

robust mulch
#

your T is on the wrong side of BC

final saddleBOT
#

@clear rivet Has your question been resolved?

clear rivet
final saddleBOT
#
Channel closed

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#
Available help channel!

Send your question here to claim the channel.

Remember:
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‱ Show your work, and if possible, explain where you are stuck.
‱ After 15 minutes, feel free to ping <@&286206848099549185>.
‱ Type the command .close to free the channel when you're done.
‱ Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

chilly raven
#

i wanted to ask which calculator is better for 0580 IGCSE
991 ex
991 cw

scarlet sonnet
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the cw is abysmal to use

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if you're used to the old design stick to ex imo

final saddleBOT
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@chilly raven Has your question been resolved?

chilly raven
scarlet sonnet
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not sure

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i definitely prefer ex but that's because i've always used that design calculator from casio

final saddleBOT
#
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Available help channel!

Send your question here to claim the channel.

Remember:
‱ Ask your math question in a clear, concise manner.
‱ Show your work, and if possible, explain where you are stuck.
‱ After 15 minutes, feel free to ping <@&286206848099549185>.
‱ Type the command .close to free the channel when you're done.
‱ Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

vague trench
#

is this good?

final saddleBOT
vague trench
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some guy told me that i should be "solving by inspection"

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i dont know what that means at all

bold zenith
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Yes

atomic moon
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Yes its good

bold zenith
#

The answer you got is correct assuming x is real

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If you don’t know complex numbers yet you’re good but given it’s x not z we should be good

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Ignore what I said, (basically there are weird numbers you might not know about that can give negative answers after exponentiation)

atomic moon
vague trench
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oh

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that sounds confusing lol

atomic moon
#

Probably based on the fact that this function is strict increasing + continious and so only one solution

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Btw when you do a change of variable, make sure to write the domain of the new variable

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Here u = 2^x is > 0

vague trench
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what do u mean by domain

atomic moon
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So writing u = -3/2 is quite a mistake but it depends the rigor of the course

atomic moon
vague trench
#

oh

bold zenith
atomic moon
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Yeah it depends on the one who grades

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Anyway its just that since ive seen this '?' After "no solution" i just make it clear that its normal to not have any solutions to u = -3/2

final saddleBOT
#

@vague trench Has your question been resolved?

#
Channel closed

Closed by @vague trench

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#
Available help channel!

Send your question here to claim the channel.

Remember:
‱ Ask your math question in a clear, concise manner.
‱ Show your work, and if possible, explain where you are stuck.
‱ After 15 minutes, feel free to ping <@&286206848099549185>.
‱ Type the command .close to free the channel when you're done.
‱ Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

versed terrace
#

I understand why a^-n equals the last one, but what is the point of having the last one there? Isn't it the same as the second one cause 1 to the power of anything is 1?

bold zenith
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Yes

versed terrace
#

wait so why is the last one there

bold zenith
#

Because it is, just in case you don’t realise it’s the same

versed terrace
#

is the last one unsimplified then?

formal trail
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the last one is there in case it isn't immediately obvious to you that the last two are equal

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since it is a useful fact sometimes

versed terrace
#

oh

versed terrace
#

alr thanks guys

#

.close

final saddleBOT
#
Channel closed

Closed by @versed terrace

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final saddleBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
‱ Ask your math question in a clear, concise manner.
‱ Show your work, and if possible, explain where you are stuck.
‱ After 15 minutes, feel free to ping <@&286206848099549185>.
‱ Type the command .close to free the channel when you're done.
‱ Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

golden cave
final saddleBOT
golden cave
#

idk where to start

#

maybe find BCA?

bold zenith
#

First step in many of these questions is to try drawing the edges in the angle you’re looking for

golden cave
#

ye

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25 5/7

#

is BCA

bold zenith
#

!15m

final saddleBOT
#

Please only use the <@&286206848099549185> ping once if your question has not been answered for 15 minutes. Please do not ping or DM individual users about your question.

golden cave
#

oh mb

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i still need help

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i got 33.43

robust mulch
#

maybe show your work instead of having us guess where you got your numbers

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heres a hint: you can tell youre wrong because the diagram is basically drawn to scale and you can see BCD is about 90

golden cave
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i calculated BCA and got 25 5/7

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and i tried calculating ACD

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and I messed up

robust mulch
#

you telling me a number is not showing your work

golden cave
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pic

bold zenith
#

It’s just saying I am 25 5/7

robust mulch
#

homie what

robust mulch
golden cave
robust mulch
#

any ideas for finding ACD?

golden cave
robust mulch
#

im not sure thats necessarily a line

golden cave
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is DCE 180

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yea

robust mulch
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can you prove thats a line?

severe verge
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that's most likely not a line

golden cave
golden cave
robust mulch
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good, you dont need to

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and dont assume it

golden cave
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ok

robust mulch
#

all you need is the triangle ACD

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what do you know about ACD?

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the triangle, not the angle

golden cave
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um

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iscocelese

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AC=AD

severe verge
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exactly

robust mulch
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thats good

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do you know about any of the angles? if so, we can crack this

golden cave
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hm

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BAD is an exterior angle

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and BAC is 900/7

robust mulch
#

youre close

golden cave
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BAD shorter + BAD longer = 360

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longer is 198

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and BAC is 900/7

robust mulch
#

ok

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keep going

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youre on the right track

golden cave
#

DAC 69 3/7

robust mulch
#

personally, i wouldnt use mixed fractions, but thats just personal preference

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either way

golden cave
#

oh shoot i understood mistake mb

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wait nvm

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so each is 55 2/7

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55+25+1

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so prolly 81

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considering i did not calculation errors

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ima review

golden cave
#

tysm

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tbh i was tryna find similar triangles

jagged flare
robust mulch
#

ohp sorry

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yes 81

jagged flare
robust mulch
#

coordbash is for cowards

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draw line segment from H to the intersection point called it I

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GHI has a special property

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first off this does involve knowing BAI is isosceles

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that one is an angle chase

final saddleBOT
#

@golden cave Has your question been resolved?

jagged flare
#

i was thinking of extending FE and AD to intersect at like X, cause IFX and IBA are simmilar and you can get the ratio of FI and IB

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then trig

robust mulch
#

nah my methods cooler

final saddleBOT
#
Channel closed

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#
Available help channel!

Send your question here to claim the channel.

Remember:
‱ Ask your math question in a clear, concise manner.
‱ Show your work, and if possible, explain where you are stuck.
‱ After 15 minutes, feel free to ping <@&286206848099549185>.
‱ Type the command .close to free the channel when you're done.
‱ Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

golden cave
final saddleBOT
robust mulch
#

im back

#

did you try my method?

heady reef
#

Bro

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There’s 1 number

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What the hell

robust mulch
#

its a regular octagon

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so technically 8 numbers

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actually 16

golden cave
robust mulch
#

8 side lengths 8 angles

heady reef
#

Thankfully ima go into finance so I don’t need to do allat

barren hound
#

the number is symbolic really

robust mulch
#

yeah theyre basically asking the ratio of x to the side length

heady reef
#

They made all this up btw

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Wtv tho I can’t help so ima js leave

robust mulch
#

isnt all math made up

heady reef
#

Yeah I think so

robust mulch
#

i presented a method before the channel closed

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how have you got along with that?

golden cave
#

mid

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HIG i don't see anything abt it

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it has 1 and x

robust mulch
#

have you showing BAI is isosceles?

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shown* not showing

golden cave
#

ye

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well

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not rlly prove

robust mulch
#

instead of looking at the side lengths of BAI, look at the angles

golden cave
#

oh

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what abt them?

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i dont see much

golden cave
robust mulch
#

so that means AI is what length?

golden cave
#

1

robust mulch
#

now draw HI

golden cave
#

ohh

robust mulch
#

what do we know about HAI

golden cave
#

root(2)

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its isocelese

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is it a right triangle

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x is prolly root(3)

#

ngl

golden cave
robust mulch
#

yup

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you get two right triangles

golden cave
#

HAI and GHI

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if im not wrng

robust mulch
#

yes

golden cave
#

so x is root(3)

robust mulch
#

yup

golden cave
#

tysm

#

.close

final saddleBOT
#
Channel closed

Closed by @golden cave

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final saddleBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
‱ Ask your math question in a clear, concise manner.
‱ Show your work, and if possible, explain where you are stuck.
‱ After 15 minutes, feel free to ping <@&286206848099549185>.
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‱ Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

upper orchid
#

So I'm currently trying to calculate the expected value of the Eurasian Nutcracker card in the game, Wingspan.

Translating this into normal dice terms, there is a tray that holds 5 six-sided dice. On a given turn, a player can move a specific number of dice from the tray outside of the tray. With that said, there are 2 special cases to consider:
case 1, there are no more dice in the tray -> in which case, all dice are rerolled and added back into the tray
case 2, all the dice in the tray have the same face turned up -> in which case you may reroll all 5 dice and add them back into the tray.

What my goal is, is to find out how many 5's & 6's I can move out of the tray on a given turn, when I may choose 1, 2, 3, 4, 5 or 6 dice at once; note, picking dice happens one at a time, so if they tray had 44435 and I could pick 3 dice, I could move the 5 and the 3, then reroll to hope I get a 5 or a 6 to pop up for my third pick.

My main question is if there are any techniques I can use to limit the amount of cases I have to consider or if this problem seems like I will need to brute force the many many cases to figure out. I don't need a specific answer, as I do have a math ed degree, but if I can cut down the work I need to do, that would be nice.

upper orchid
#

.close

final saddleBOT
#
Channel closed

Closed by @upper orchid

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upper orchid
#

Upon rereading the rules, it's not a homework question

latent dragon
#

I feel like you can still recieve help with this?

plucky rover
#

These channels don't exist purely for homework questions lol

upper orchid
#

oh ...

latent dragon
#

use .reopen

plucky rover
#

.reopen

upper orchid
#

.reopen

final saddleBOT
#

✅

opal plinth
plucky rover
#

Pre-university?!

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That just feels like a rule that exists in letter but is just ignored entirely

opal plinth
#

Yeah I know, might be a bit outdated

#

a tray that holds 5 six-sided dice
when I may choose 1, 2, 3, 4, 5 or 6 dice at once
How do you choose 6 dice from a tray that holds 5 maximum?

formal trail
#

it's not a rule but the likelihood of being helped effectively drops dramatically the farther away from university the question gets

plucky rover
#

The farther from pre-university you mean

upper orchid
opal plinth
#

Oh ok so no matter what happens you can choose to take 6 total

upper orchid
#

hense why I have the different cases to consider.

opal plinth
#

Ok I'm even more confused

upper orchid
#

ok, where are you getting lost

opal plinth
#

Say it's my turn, the tray can contain 0 to 5 dice, what's my goal? To end in a state where there are as many dice that rolled 5 or 6 out of the tray?

upper orchid
#

So on a given turn you are allowed to "take" X amount of dice, where X is an integer ranging from 1 to 6 (X is decided for you).

when you "take" a dice, you gain a resource and set off to the side to be re-added to the tray when the tray gets rerolled or becomes emptied. 2 faces of the 6 sided dice allows us to gain a resource we want (in the game, it's wheat, but that's not important here).

#

The reason why "take" is in quotations, is because you don't own the dice or keep it, you just move it outside of the tray and collect what is shown ontop of the dice.

opal plinth
#

Ok so X is not in the player's control, and the gains happen whenever you pick up a dice, not just after you're done manipulating the dice

upper orchid
#

X is not in the player's control

the gains happen when then the dice is move by the player from inside the tray to the outside.

If a dice is added back into the tray from the outside or is rerolled, nothing is gained.

opal plinth
#

Nothing is gained but the previous gains are kept

upper orchid
#

correct

opal plinth
#

And you're only interested in the 5s and 6s

upper orchid
#

yeah

#

if you prefer, I can put everything in the language of the game, but those are the 2 faces I want to see

opal plinth
#

No it's fine, I just think there are a lot of conditions and the player has very little control

#

Like you would obviously pick all the 5s and 6s that you can from the tray as a first step

upper orchid
#

yeah

#

It's the being able to reroll all of the same face that is being the bane of my existance

opal plinth
#

Then if you still have moves, either the tray is empty already or you try to leave it with only one "kind" of dice (same face)

#

But that can also take moves

#

6 is not a lot of moves, and if you say it's almost always 4, that's even worse

#

Like there's really not a lot you can do

#

What exactly do you want an answer for? Some kind of probability, expected value?

upper orchid
#

expected value

opal plinth
#

And you consider all possible starting configurations (1 to 5 dice in the tray, 6 faces per dice)?

upper orchid
#

30 total cases

opal plinth
#

Are they even equally likely?

upper orchid
#

Ok

#

So, the dices are fair

#

The issue is, there can be 1 to 5 dice in the tray at the start of the turn and 6 possible amount of dice you may be able to select, so each turn you have 30 different cases to consider.

Again, I am just trying to see if I can limit the calculations I need to do here

opal plinth
#

But don't the starting configurations depend in part on the other players previous turns? Maybe that's insignificant?

upper orchid
opal plinth
#

Ok so you consider all starting configurations to be equally likely

upper orchid
#

it doesn't matter,

my goal is to get 30 expected values, although I expect the math to get to most of them to be roughly the same

#

That is to say, once I find out how to do a couple, the rest will be easy

opal plinth
#

Fair enough

#

Let N be the number of dice in the tray and X the number of dice you can "move" (pick)

#

With N=1, X=1, either the dice is 5 or 6, or you reroll

#

The expected value E in this case is 5/6 + 6/6 + 4/6(expected value after reroll)

#

For the after reroll part, you have a 1-(5/6)^5 chance to get at least one 6, and a (5/6)^5-(4/6)^5 chance to get no 6 but at least one 5

#

Honestly I don't think there is much you can do to "limit the amount of cases"

#

The reroll parts with other values of N and X are going to be ugly

upper orchid
#

welp, it was worth a shot

#

at the very least, the different cases are going to show up in each other, which is nice

opal plinth
#

Yeah some parts will

upper orchid
#

ok, I'll check there

opal plinth
#

But you probably want to formalize your problem and cut out as much as possible

upper orchid
#

after I see if my geometric sequence idea goes somewhere

#

anyways, thanks for your help :)

opal plinth
#

(the more concise your question the better your chances at an answer from other people - that includes making use of the domain's language, things like random variables, discrete uniform distribution, etc)

#

You're welcome catthumbsup

upper orchid
#

.close

final saddleBOT
#
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final saddleBOT
#
Available help channel!

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Remember:
‱ Ask your math question in a clear, concise manner.
‱ Show your work, and if possible, explain where you are stuck.
‱ After 15 minutes, feel free to ping <@&286206848099549185>.
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‱ Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

thin cloud
#

So I'm making a cake in desmos for my friend birthday ( yes you read it right ) And I want to make that red part wrap around the cake (idk what's it called )

thin cloud
#

I tried to use trig function but it doesn't seems 3d

bold zenith
#

What would be ideal is the projection of a sine wave on the surface of a cylinder and then project that onto the “screen”

#

Doing ellipses and straight lines were easy but this is difficult

#

You could try faking it with trig like you said

formal trail
#

not perfect but you can add a sine wave to a curve and it sort of gives that effect

#

where the curve acts sort of like the "midline" of the sine wave

bold zenith
#

Copy the blue ellipse section just above the wave onto it by adding it to the sine wave

#

Like if you just draw a curve where you want the icing and then just add sin x to it what does it look like

thin cloud
#

Ig I misunderstood what you said

bold zenith
#

F(x)+sin(x)

thin cloud
#

oh

bold zenith
#

Sin(f(x)) is called composition

#

I meant adding it in a literal way

thin cloud
#

Yeah i understand what you said now

#

that's not bad, I'll try to fix it

bold zenith
#

Change frequency and period so the end points have sin(x)=0, we could work it out if you know the start and end x

#

Then you should shift it down

#

Like remove the +5

#

It appears the start and end x are -14 and 14

thin cloud
#

Yup ik

#

Looking gud

bold zenith
#

!bnuuy

final saddleBOT
thin cloud
#

awesome

#

thanks y'all!!!!

#

.close

final saddleBOT
#
Channel closed

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final saddleBOT
#
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Remember:
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‱ Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

ornate tree
#

Translate each of the following statements into logical expressions using predicates, quantifiers, and logical connectives.
Let:

  • P(x): “x is perfect.”
  • F(x): “x is your friend.”
  • Domain: All people.
  1. Some of your friends are not perfect.
  2. If someone is perfect, then they are your friend.
  3. Everyone who is not your friend is not perfect.
  4. There exists someone who is not your friend and is perfect.
  5. Every perfect person is your friend.
  6. You have at least two friends who are perfect.
  7. If someone is your friend, then either they are perfect or they are not.
  8. There exists exactly one perfect friend.
  9. Not all perfect people are your friends.
  10. If everyone is your friend, then everyone is perfect.
ornate tree
#

1 6 7 8

plucky rover
#

Hullo

ornate tree
#

Okay so, I was told by a senior helpful that question 1, 6, 7, and 8 are incorrect

ornate tree
plucky rover
#

Well 1 is immediately incorrect cuz it doesn't contain the friend information at all

ornate tree
plucky rover
#

Ah cool Lemme do that then

ornate tree
#

Tysm 🧡

plucky rover
#

2, 3 are fine

#

4 is fine

#

5 is fine

#

6 doesn't work cuz what does x ≄ 2 even mean

#

7 is.. interesting

#

Same problem with 8 as with 6

#

9 is fine

#

10 is fine

#

The reason I say 7 is interesting is cuz... Uh

#

If you're working in classical logic, that's just a true statement

ornate tree
#

ye, that works on the truth table

plucky rover
#

But yea you can still write it using logic notation

ornate tree
#

Alright

#

Can 10 be simplified further?

plucky rover
#

It will be a tautology but well whatever

#

No, 10 is as simple as it can be I think

ornate tree
#

$\forall x (F(x) \to P(x))$

soft zealotBOT
#

This is sad 😱

plucky rover
#

Nope, this just means all your friends are perfect

ornate tree
#

oh bruh

#

alright, I'll start working on the correction

plucky rover
#

Good luck

craggy plank
plucky rover
#

Tag me if you need anything

ornate tree
#

Alright, appreciate it

#
  1. $\exists x (F(x) \to \neg P(x))$\
  2. $\exists x \exists y (F(x) \to P(x)) \wedge (F(y) \to P(y))$\
  3. (I'll skip this part as this is classical logic)\
  4. $\exists x (P(x) \wedge F(x)) (x = 1)$\
soft zealotBOT
#

This is sad 😱

plucky rover
#

1 is wrong I think

ornate tree
#

oh wait

#

yeah, incorrect notation

plucky rover
#

6 needs a little more information

#

Actually no 6 is wrong too

#

As a little nudge

#

Abandon implications

#

For 1 and 6

ornate tree
#

yeah.....that's "and"

plucky rover
#

Yes

ornate tree
#

idk why I'm so obssessed with arrows

plucky rover
#

People starting out with logic always are

ornate tree
#
  1. $\exists x (F(x) \wedge \neg P(x))$\
  2. $\exists x \exists y (F(x) \wedge P(x)) \wedge (F(y) \wedge P(y))$\
  3. (I'll skip this part as this is classical logic)\
  4. $\exists x (P(x) \wedge F(x)) (x = 1)$\
soft zealotBOT
#

This is sad 😱

plucky rover
#

6 needs a little bit more

#

And again, x = 1 doesn't make sense for 8

#

You can't say people are greater than 2

#

But yes smth close to that

#

Don't delete stuff lol, it's fine logic is a lot of book keeping

#

Oh also 1 is correct

ornate tree
#

Let's begin with 8

plucky rover
#

Sure

ornate tree
#

My idea is to confine the domain at x = 1

plucky rover
#

6 is easier to fix though

#

Like you're missing one little bit

#

And the idea with 6 will help with 8

#

But up to you

ornate tree
#

Alright, let's begin with 6

plucky rover
#

Cool

ornate tree
#

ye....since you mention it lol

plucky rover
#

So currently the only problem 6 can run into is..

#

x and y can refer to the same person

#

And then you might only have one friend who's perfect

#

But you want at least two

ornate tree
#

damn.....I never come up with this problem

plucky rover
#

So what are we to do

ornate tree
#

x != y is the easiest solution I presume

plucky rover
#

Yup there you go

#

Just an extra and

#

Cool now that we are done with 6

#

Does this idea give you a hint for 8

ornate tree
#
  1. $\exists x (F(x) \wedge \neg P(x))$\
  2. $\exists x \exists y (F(x) \wedge P(x)) \wedge (F(y) \wedge P(y)) \wedge (x \ne y)$\
  3. (I'll skip this part as this is classical logic)\
  4. $\exists x (P(x) \wedge F(x)) (x = 1)$\
soft zealotBOT
#

This is sad 😱

ornate tree
plucky rover
#

Sure sure

ornate tree
#

There exists exactly one perfect friend.

plucky rover
#

Yes

ornate tree
#

I don't have any idea actually, aside from missing wedge

plucky rover
#

Fair enough

#

Well we want there to exist an x such that both are true

#

But we want there to exist exactly one such x

#

So what do we want for the others

ornate tree
#

the others are false

plucky rover
#

Yes

#

So how can you write it

ornate tree
#

yeah but what's wrong with this version?

#

like if I just add wedge in it

#

$\exists x (P(x) \wedge F(x)) \wedge (x = 1)$\

soft zealotBOT
#

This is sad 😱

plucky rover
#

x = 1 doesn't make sense

#

What does it mean for a person to equal a number

ornate tree
#

hmm...so if I understand it right. x means a person's name

#

or simply means a person's identity

plucky rover
#

Let's not get philosophical about what differentiates a person

ornate tree
#
  1. $\exists x (F(x) \wedge \neg P(x))$\
  2. $\exists x \exists y (F(x) \wedge P(x)) \wedge (F(y) \wedge P(y)) \wedge (x \ne y)$\
  3. (I'll skip this part as this is classical logic)\
  4. $\exists x (P(x) \wedge F(x)) \wedge (P(x) = 1)$\
soft zealotBOT
#

This is sad 😱

plucky rover
#

Still doesn't work

#

You're trying to use the idea of cardinality

#

Unfortunately we do not have that yet

ornate tree
#

hmmmm

plucky rover
#

Like I said

#

You want there to exist one person such that both properties are true for them

#

AND for everyone else, you want at least one of them to be false

#

Try just writing this thing exactly

ornate tree
plucky rover
#

Well if none are false then both are true

ornate tree
#

but not just all of them

plucky rover
#

And then your perfect friend isn't unique

plucky rover
#

We just want exactly one perfect friend

#

We eventually define a quantifier that reduces the amount of writing for this, $\exists !$

soft zealotBOT
#

Xavier đŸŒș

plucky rover
#

But I imagine the goal of this exercise is to make you define that yourself

ornate tree
#

So basically we exclude this special guy, and for others we don't want them to fulfill the characteristc of this special guy

#

is that correct?

plucky rover
#

Yes

#

There's multiple ways to do this

#

And funnily enough the cleanest one uses implication this time

ornate tree
#

$\exists x (P(x) \wedge F(x)) \vee \neg (P(x) \wedge F(x))$

plucky rover
#

Close to the idea

soft zealotBOT
#

This is sad 😱

plucky rover
#

You want to incorporate other people into this as well

ornate tree
#

yes

plucky rover
#

So $\exists x (P(x) \land F(x))$ is fine

soft zealotBOT
#

Xavier đŸŒș

plucky rover
#

Now you want to add a condition saying that no one else satisfies this

ornate tree
#

no one else satisfies this
Makes me want to add forall in front of the second helpparens

plucky rover
#

Good thinking

#

And it's correct

ornate tree
#

$\exists x (P(x) \wedge F(x)) \vee \forall x \neg (P(x) \wedge F(x))$

soft zealotBOT
#

This is sad 😱

plucky rover
#

Close

ornate tree
plucky rover
#

You want to exclude this special person from the second condition though

#

Also maybe use a different variable for the forall

plucky rover
ornate tree
#

$\exists x (P(x) \wedge F(x)) \vee \forall y \neg (P(y) \wedge F(y)) \wedge (x\ne y)$

plucky rover
#

Having forall, you can make generalizations about every element of the set

#

Sky you don't just get to add a bracket there needs to be an operator in between

soft zealotBOT
#

This is sad 😱

plucky rover
#

It's close but wrong

#

Wait

#

No it's correct I'm blind

ornate tree
#

This is god damn complicated 💀

plucky rover
#

Now needs one bracket around the entire second part

plucky rover
ornate tree
#

$\exists x (P(x) \wedge F(x)) \vee (\forall y \neg (P(y) \wedge F(y))) \wedge (x\ne y)$

soft zealotBOT
#

This is sad 😱

plucky rover
#

$\exists x (\forall y (P(y) \land F(y)) \to (y = x))$

ornate tree
#

oh....makes sense

soft zealotBOT
#

Xavier đŸŒș

ornate tree
#

it's a miracle that I can read this

plucky rover
#

So the bracket should end at that

plucky rover
#

Also actually wait yours doesn't work

#

Cuz if y = x, the forall fails

#

What you want instead is, forall y, either (not perfect friend) or (equal to x)

#

So you actually want an or with equality, instead of and with inequality

craggy plank
#

hmm

craggy plank
#

sry, I was changing my seat

plucky rover
#

You can't do that at this stage lol

#

Forall includes everything unfortunately

#

So you're gonna have to make the thing inside true for everything

#

It is extremely annoying, I know

craggy plank
plucky rover
#

Yes, hence it fails

plucky rover
craggy plank
#

This works for any y instead of x = y

#

But if x = y the entire system fails

plucky rover
#

Yes that shouldn't be the case

#

Let me show you what I'm aiming for

#

∃x (P(x) ∧ F(x)) ∧ (∀y (x = y) ∹ ¬(P(y) ∧ F(y)))

#

You don't want your system to fail at all

#

For any given y, either they're equal to x, or they are NOT a perfect friend

#

You might notice that

plucky rover
craggy plank
#

Yep, they either fall into the first or the second category

plucky rover
#

This is probably one of the very few cases where the implication is easier to reach

#

And easier to understand

craggy plank
plucky rover
#

Yes

craggy plank
#

Hmm

#

Is there anyway to patch this drawback on the current basis as far as you know?

plucky rover
craggy plank
#

Oh, bruh. Didn’t notice that

#

Lemme check

plucky rover
#

Lololol

#

It just turns your inequality to an equality and uses or instead of and

craggy plank
#

I see, I’ll check it around later.

#

Appreciate your help

#

Have a good one 🙂

plucky rover
#

You too! đŸŒș

#

The default hibiscus looks so much better than the discord one

#

It's sad

#

\đŸŒș

#

They don't even let you do this anymore

craggy plank
#

I’m too lazy to take out my laptop again

plucky rover
#

Gonna get Nitro just to be able to send default hibiscuses

#

Lololol you can close it from this account

craggy plank
plucky rover
#

Lmao yeah for sure

craggy plank
plucky rover
#

Sky

craggy plank
#

:sigh:

plucky rover
#

Look at which account you're on

craggy plank
#

😭😭

plucky rover
#

Smh no

#

The bot has deemed you helpful, and so you are

#

Your opinion is irrelevant on this

plucky rover
craggy plank
plucky rover
#

It isn't no

#

I have not even formally studied predicate logic yet

#

That isn't a joke

#

It's just from years of doing related stuff and having conversations with people

craggy plank
#

Sadge

#

Alright imma close this one

#

Bye :))

#

.close

final saddleBOT
#
Channel closed

Closed by @craggy plank

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#
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‱ Show your work, and if possible, explain where you are stuck.
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‱ Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

stray notch
#

If i have a step function like this. Will the square of that function be what i wrote inside the pic?

plucky rover
#

Yes

#

Which is just equal to 1 everywhere

bold zenith
#

$f(x)^{2}=1$

soft zealotBOT
#

BBMaths

bold zenith
#

This highlights an important fact that f(x) might not be constant if you started from this ^

stray notch
#

Ohh

#

Alr thx a lot

#

.close

final saddleBOT
#
Channel closed

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#
Available help channel!

Send your question here to claim the channel.

Remember:
‱ Ask your math question in a clear, concise manner.
‱ Show your work, and if possible, explain where you are stuck.
‱ After 15 minutes, feel free to ping <@&286206848099549185>.
‱ Type the command .close to free the channel when you're done.
‱ Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

short wraith
#

hints

final saddleBOT
short wraith
twin pivot
#

Good morning. @short wraith

#

Quick note: if this is from a live exam, the rules say we can’t provide help in that case. If it’s just practice material, then it’s fine.

quaint rampart
#

first thing you've gotta do is look at the first summation

#

as we know f(1), f(2) can be found by taking n=2

short wraith
quaint rampart
#

after knowing f(2) we can find f(3) from n=3 substitution

short wraith
#

1,2,6,18,54

ivory bear
quaint rampart
#

try to find a pattern

quaint rampart
short wraith
#

i see

short wraith
ivory bear
quaint rampart
#

;-;

#

he's tryna help dude

#

that's very rude

short wraith
#

lol is funny no?

short wraith
valid carbon
valid carbon
short wraith
quaint rampart
#

hmm

short wraith
#

then?

#

should I close it?

quaint rampart
#

1, 2 * 3^0, 2 * 3^1, .....

#

first term doesn't fit

valid carbon
#

escape them

short wraith
#

why>

twin pivot
short wraith
#

i seeeeeeeeeeeee

quaint rampart
#

;-;

short wraith
#

but options are odd

twin pivot
valid carbon
craggy plank
#

Is there any reason behind this?

quaint rampart
#

he's asking.

#

no accusations were made.

short wraith
#

no he is accusing

quaint rampart
#

just tell him it ain't an exam question then

valid carbon
craggy plank
short wraith
#

like he is sitting behind me in the exam hall....lool

valid carbon
short wraith
#

pattern is invisible to me

#

1,2,6,18

valid carbon
#

drop the 1.

short wraith
#

yeah i did

twin pivot
#

Call me observant, but a blurry photo of a multiple-choice question, paired with a rushed request for ‘hints,’ statistically screams ‘exam situation.’ And according to the rules, that’s academic dishonesty.

valid carbon
#

its a gp

bold zenith
#

We don’t have to debate over if this is an exam question, just take a more zoomed out screenshot

short wraith
#

2(3^0,3^1,3^2)...

valid carbon
bold zenith
#

lol no

valid carbon
#

OP is still obnoxious tho

valid carbon
short wraith
#

i got the paatenr

#

it is C

bold zenith
#

We don’t even talk the same

short wraith
#

3^m-1

bold zenith
#

And Alfred says so much stuff I wouldn’t have time to type my own stuff

short wraith
#

it is GP simple

bold zenith
#

(No disrespect) I think more detail is good as long as it doesn’t confuse the helpee

twin pivot
#

If this is practice material, please confirm the source (book/worksheet). Once that’s clear, I’ll be happy to give hints.

short wraith
#

I don't need irrelevant advices...troll stop or I complaint in modmail

short wraith
#

i said 10 minutes ago

#

.close

final saddleBOT
#
Channel closed

Closed by @short wraith

Use .reopen if this was a mistake.

craggy plank
short wraith
twin pivot
#

<@&268886789983436800>

#

Could you please clarify? I just quoted the rules about exam material, but the OP disagreed. I’d rather get an official confirmation.

short wraith
#

just wait for the conclusion

bold zenith
craggy plank
#

.reopen

final saddleBOT
#

✅

short wraith
#

.reopen

quaint rampart
#

I vouch for alfred.

brisk charm
bold zenith
short wraith
#

your self observation doesn't prove anything

bold zenith
#

Why are we arguing

short wraith
#

he accused me

valid carbon
#

not worth t

craggy plank
#

There are thousands of questions asked and presented in similar way

short wraith
#

the way he was giving the time in the channel for 15 minutes is tottaly wasting

brisk charm
#

Okay please stop arguing about this

#

Let him get math help

valid carbon
#

hes done

craggy plank
#

Is he?

short wraith
#

already done

valid carbon
#

.close

final saddleBOT
#
Channel closed

Closed by @valid carbon

Use .reopen if this was a mistake.

#
Available help channel!

Send your question here to claim the channel.

Remember:
‱ Ask your math question in a clear, concise manner.
‱ Show your work, and if possible, explain where you are stuck.
‱ After 15 minutes, feel free to ping <@&286206848099549185>.
‱ Type the command .close to free the channel when you're done.
‱ Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

foggy wren
final saddleBOT
foggy wren
#

I'm a little confused on what to do here

magic walrus
foggy wren
#

I think you can split it into two cases but I don't know if that encompasses all of s

#

So far what I've got is for small values:

#

$I(s) = \frac{s^3}{3} - \frac{7s^5}{30} + \frac{141s^7}{840}+...$

soft zealotBOT
#

Katrro

foggy wren
#

and for large:

#

$I(s) = \frac{Cos(s)}{s} + \frac{Sin(s)}{s^2} - \frac{2Cos(s)}{s^3} +...$

soft zealotBOT
#

Katrro

valid carbon
#

$\cos$

soft zealotBOT
#

ΠΔρσυ

twin pivot
#

Good morning. @foggy wren

#

Source?

foggy wren
twin pivot
#

Source of the problem.

foggy wren
#

from one of my classes

twin pivot
#

Strange.

foggy wren
#

how is that strange

twin pivot
#

What course are you doing?

foggy wren
twin pivot
#

Can i see the exercise 3?

proper dagger
#

what does that show here though? are you suspecting exams again?

#

if you are, then I'd recommend not immediately assuming that unless it's super obvious or something? or you can always modmail/modping, I suppose.

twin pivot
#

This exercise is very complicated

#

You should start by reading this.

foggy wren
#

It's just an expansion

#

Also this is question 3

#

Which is how I got the answer for large x since if you assume x>>1 then the integral turns into this one

twin pivot
#

for $s\ll1$ (Maclaurin development)

soft zealotBOT
#

Alfred Eisenberg

twin pivot
#

$$
\frac{x\sin x}{1+x^{2}}
=(x-x^{3}/6+x^{5}/120-\cdots),(1-x^{2}+x^{4}-x^{6}+\cdots)
= x^{2}-\frac{7}{6}x^{4}+\frac{47}{40}x^{6}-\frac{5923}{5040}x^{8}+\cdots
$$

soft zealotBOT
#

Alfred Eisenberg

twin pivot
#

Okay so far ?

foggy wren
#

you forgot the first x before the sin expansion but that's what I've got

twin pivot
#

Integrating deadline

#

$$
\boxed{;
I(s)\sim \frac{s^{3}}{3}-\frac{7}{30}s^{5}+\frac{47}{280}s^{7}-\frac{5923}{45360}s^{9}
+\cdots\qquad (s\to0)
;}
$$

soft zealotBOT
#

Alfred Eisenberg

twin pivot
#

Okay so far ?

foggy wren
#

That's what I got yea

twin pivot
#

With the first 4 terms the relative error is $<1%$ for $0<s\lesssim0.65$.
(Adding more terms from the series product extends the range: 12 terms $\Rightarrow$ $<1%$ up to $s\approx0.8$; 20 terms $\Rightarrow$ $<1%$ up to $s\approx0.95$.)

soft zealotBOT
#

Alfred Eisenberg

twin pivot
#

Yes?

foggy wren
#

I don't know how to compute it with these coefficients because they seem random to me

twin pivot
#

Let me explain.

undone matrix
twin pivot
#

$$
\frac{x\sin x}{1+x^2}=\underbrace{\bigl(x\sin x\bigr)}{\sum{m\ge0}\frac{(-1)^m x^{2m+2}}{(2m+1)!}};
\underbrace{\frac{1}{1+x^2}}{\sum{k\ge0}(-1)^k x^{2k}}
$$

soft zealotBOT
#

Alfred Eisenberg

twin pivot
#

Okay so far?

foggy wren
#

yes

twin pivot
#

It is just Cauchy product.

#

Shall we skip this?

foggy wren
#

yea you can skip that

final saddleBOT
#

@foggy wren Has your question been resolved?

undone matrix
tranquil pine
soft zealotBOT
foggy wren
#

this way seems like it takes a lot more effort computing everything

undone matrix
#

hmm, then you may want to check your work and verify that it converges to pi/2e for s->infinity

foggy wren
#

.close

final saddleBOT
#
Channel closed

Closed by @foggy wren

Use .reopen if this was a mistake.

final saddleBOT
#
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soft heart
final saddleBOT
soft heart
#

.close

final saddleBOT
#
Channel closed

Closed by @soft heart

Use .reopen if this was a mistake.

#
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
bold zenith
#

Nvm it didn’t scroll down sorry, just saw image

craggy plank
final saddleBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
‱ Ask your math question in a clear, concise manner.
‱ Show your work, and if possible, explain where you are stuck.
‱ After 15 minutes, feel free to ping <@&286206848099549185>.
‱ Type the command .close to free the channel when you're done.
‱ Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

silk fjord
final saddleBOT
silk fjord
#

My idea was to use the midpoint of y-values for A, and the midpoint of x-values for B

#

so I had A(0,4) and B(7.5,0)

pliant shore
silk fjord
#

but that resulted in ~17.23 which is greater than the actual answer, 17

silk fjord
#

have not

#

what is snell's law?

pliant shore
#

what I mean is that you must have a setup like so

old quarry
pliant shore
#

where you have the angle of incidence = angle of reflection

#

basically, it's symmetrical

silk fjord
#

I'm not sure I understand how that would work here though

#

are you saying PA and BQ need to intersect?

pliant shore
#

let me draw it

silk fjord
#

Oh I see

#

So it's like perfect bounces

pliant shore
#

yes

silk fjord
#

How do I determine the perfect coordinates or lengths though?

#

Is it just midpoint of Py and 0?

#

And then midpoint of Qx and 0

pliant shore
#

no, so given that A = (0, a)

#

can you find the equation of the line AP?

#

then that gives you the equation of AB

silk fjord
#

Using distance formula?

pliant shore
#

point-slope form or just y = mx + c

silk fjord
#

Oh yeah that makes more sense

#

It would be y=((5-a)/(4-0))x+a?

#

$y=\frac{5-a}{4-0} x + a$

soft zealotBOT
#

UCYT5040

silk fjord
#

because a is the y-intercept

pliant shore
#

yep

#

and then, how are the slopes of AP and AB related?

silk fjord
#

they are perpendicular

pliant shore
#

no

silk fjord
#

oh wait its just

#

opposite

pliant shore
silk fjord
#

negative

pliant shore
silk fjord
#

isnt that def of opposite or did i say that wrong

#

?

thin cloud
#

Isn't the least distance is just the distance of reflection of P through y-axis and reflection of Q through x-axis?

pliant shore
silk fjord
#

ah ok

#

anyway, then the slope of BQ should be the same as PA then right?