#help-49
1 messages Β· Page 224 of 1
Alright, pic it is @safe notch
in 30 minutes i gotta go eat and go collage
hmm
Dude I'm attending a meeting and simplifying SHM at the same time
ohhh mai god
i'm in office too
Nah you're fine
yall are so busy
We wouldn't be here if we couldn't help
thanks guys for ur help
Yeah sure
my speeds are conspiring against this man
lol don't tell me you found it online
i won't discuss it publicly lol
what
I meant the book
ye i know, but yea i did. not gonna say anything more than that
ahhh okay
unless you wanna wait another 25 minutes, do it
if you can
Yeah sure
What part?
,rccw
now i wish i had my copy of Sears and Zemansky on hand
that's not clear
you sent this picture twice
special cases case i
it says the mean position at y=0
aghhhh and i dont get why it took
y as the displacement not x
idk man so much things
here
Ehhhh, y = 0 or x = 0, both reference to the Origin
let's say you have circular motion
k
now, let's say you're standing to the side of the circle
the component of motion you'll see is different depending on which side you stand on
yea
if you stand on the red side, you see the y-component.
likewise, if you stand on the green side, you see the x-component
so whether y or x as the displacement depends on where you're looking at the object from
but in the end they describe the same motion really
just from different points of view
Exactly, and them being zero is them being at the origin
have you ever been to a carnival
You need help with that statement?
yeah
Answer this first
i need
been years i havent been but yea few times
then have you seen games where they put something like a plastic or rubber duck that moves around in a circle
yeah
then players would stand to one side and try to hit the duck
a horse
wwhat
no
no social experience aswell smh
Even I'm unfamiliar with that, we ride the horses
i suppose you're talking about a carousel
that works
imagine a carousel with one horse only then
hopefully this makes sense for the x component
Okay wait
the point particle has circular motion but its projection performs simple harmonic motion
exactly.
in the horizontal line
Imagine you stand with your eyes at the axis, so you eyes are at the same axis as the plane
hence theta = wt
which you mentioned earlier @safe notch
should help connecting to sinusoids
wth
oh okay great
Look at one colour first
-A is the A' you mentioned earlier
yeah
Yes
yes
so why the hell book is yellling its x= o an y=o
unless you're using a cosine wave
They're considering both vertical and horizontal components
origin
congratulations, you just answered your own question
waaaaaaaait a secc
Assuming it's a sine wave though
which it is in our analysis
let's not get into cosine wave just yet
aghhh god guys im gatting late for school can we get on this at exactly 10 hours
don't think i will be here at that time, but do what you need to
Well my schedule fluctuates, ping me IG
Yeah no problem, focus on your studies
Anytimeπ«‘
.close
Closed by @safe notch
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
help
can you translate?
@tidal turret Has your question been resolved?
P is the power set of x, R is a relation on P we need to prove is an equivalence relation
somehow we have to use iii)
@tidal turret Has your question been resolved?
@tidal turret Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
can i replace cos(90-a) with sin(a)?
[insert some kind of funny response here about imaginary math-bureaucratic red tape]
yes ofc you can do that.
its just that when i plug the numbers into the calculator i get different answers
hang on. a might not be ok
eg
b is stated to be acute, so b is fine
is ur desmos set to radians
but a is not necessarily acute
check for rad(ians) or deg(rees)
okay now it works
yeah, for both desmos or an actual calculator, always make sure youre working with the right measure > one of the classic fumbles
arcsin0.45 is ~27 so we're good
yeah the identity works for all a in R
hm aight, sorry for the misunderstanding
Closed by @lucid delta
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Do you know the definition of an equivalence relation?
equiv rela = sym + refl + transi
to prove it's an equivalence relation, you'll need to prove those three properties
x R y => y R x,
proving reflexivity is straightforward
0 = 0
reflexivity: you need to show x^2 - y^2 = 93x - 93y when x=y
x R x <=> x^2 - x^2 = 93x - 93x
yep, that
For symmetry, I'll give you a hint: can you simplify x^2 - y^2 = 93x - 93y?
x^2 - x^2 = 93x - 93x
x^2 - x^2 -93x + 93x = 0
(x^2 - x^2) + (93x - 93x) = 0
this holds for any x β A
oops, sorry. I meant symmetry
you've shown it's reflexive, which is good π
hint: x^2 - y^2 is a difference of squares
x R y => y R x
Assume: x^2 - y^2 = 93x - 93y
x^2 - 93x = y^2 - 93y
multiply by -1 both sides
93x - x^2 = 93y - y^2
y^2 - x^2 = 93y - 93x
=> y R x
Heyyy guys
nope, because x^2 - y^2 = 93x - 93y and y^2 - x^2 = 93y - 93x are different equations.
so you can't just multiply by -1
!occupied
Someone else is already using this help channel. If you need help with a question, please open your own help channel/thread (see #βhow-to-get-help for instructions).
can you simplify x^2 - y^2 = 93x - 93y?
(x-y)(x+y) = 93(x-y)
yep. now can cancel the (x-y)s?
you'll need to justify why
we are diving by 0?
suppose the relation consist of R β {(a,a) | a β A}
when x = y
yep. so if x R y and x = y, isn't that just reflexivity?
which we've already shown?
yes but suppose R = {(1,1)} and A = {1}
we have two cases. either x = y which is reflexivity, or x != y so we can divide by (x-y).
this is reflexive and symmetric
then symmetry and transitivity are hold by vacuous truth.
In mathematics and logic, a vacuous truth is a conditional or universal statement (a universal statement that can be converted to a conditional statement) that is true because the antecedent cannot be satisfied.
It is sometimes said that a statement is vacuously true because it does not really say anything. For example, the statement "all cell ...
there are no two elements x,y in A where x != y, so it's symmetric by default
Just like the relation on A = {} is all three by vacuous truth
what I am saying is
βx,y β A,
transitivity: x R y => y R x
like is possible all pairs in the relation are x = y
transitivity doesn't have a problem with that
Yep. Let's test that on A = {1}.
All the elements in A are 1, so there's only one we need to check
1 R 1 => 1 R 1, so it's symmetric
i did swap the elements over, you just don't notice it because they're the same
yes, but going back to our proof of symmetry, division by 0 is impossible here
indeed. but we don't need to cancel
reflexivity proves symmetry
Suppose S is another relation. I'm not going to tell you what it is, because you don't need to know.
Suppose also that S is reflexive - so x S x.
Now, knowing that, prove x S y => y S x when x = y because there's only one element in the set.
To put it another way, because there's only one element in A, we know
for all x,y in A, we must have x = y.
I think it can be expressed in a better way dude
,, x \mathcal{R} y \iff x^2 - y^2 = 93x - 93y \ x \mathcal{R} y \iff \begin{cases} x = y \ \text{or} \ x + y = 93 \end{cases}
Renato
ye, that's a good way to put it
if you re define it like this, then symmetry is two cases, when x = y which is already proved by reflexiveness and the other case which we care of
transitivity should also pop out from that
x R y <=> (x = y) or (x + y = 93)
Symmetry proof:
there's 2 cases, when x = y this is proved by reflexivity
second case is when x R y which is x + y = 93 and because sum is commutative
y + x = 93 and thus,we conclude y R x
βx,y,zβA ,xRy, yRz => xRz
mmm
Bonita relaciΓ³n de equivalencia.
Transitivity proof:
Assume: x,y,z β A, such that
xRy and yRz, thus
[(x=y) or (x+y=93)] and [(y=z) or (y+z=93)]
the cases where x=y, y=z have been proved by reflexivity, so it can be simplified to proving this: (x+y=93) and (y+z=93)
both need to happen simultaneously, from subtracting both you get
x - z = 0 => x = z, since we already proved reflexivity, we conclude xRz
hint: if x=y, x=z, or y=z, this is just reflexivity.
@tidal turret Has your question been resolved?
it's not antisymmetric
antisymmetry: xRy, yRx => x = y
counterexample, 80 R 13
xRy <=> (x=y) or (x+y = 93)
so, 80 + 13 = 93 => 80 R 13
and . . . 13 + 80 = 93 => 13 R 80
but 13 β 80
for ii) I am thinking π€
thanks dude, I appreciate it 
we need to find the equivalence class for every element in A, mmm
so for example
[1] = {y β A | y ~ 1} β A
where A = {n β N | n <= 92}
[1] = {y β N | y <= 92 and y ~ 1} β {n β N | n <= 92}
y ~ 1 => (y = 1) or (y + 1 = 93)
thus, [1] = {1, 92}
now for 2, the equivalence class of 2 is
[2] = {y β N | y <= 92 and y ~ 2} β {n β N | n <= 92}
y ~ 2 <=> (y=2) or (y + 2 = 93)
so [2] = {2, 91}
yes
how to find them all?
do you see a pattern? try to find [n] for arbitrary n
from math, we know the equivalence class of a representative of a class is equal to the equivalence class of another representative from the same class
what I mean is,
if [β‘] = {β‘,β} then [β] = {β‘,β}, we conclude [β‘]=[β]={β‘,β}
based on prior work what do you think [3] is?
easy, [3] = {90,3}
what about [n] for arbitrary n?
all correct!
and from what I said above, the representative of an equivalence class has same equivalence class as the other representatives
meaning [n] = [93-n] = {n, 93-n}
what are enough representatives to describe all classes?
idk
idk?
recall [n]={n,93-n}
a drawing would be appreciated
You really don't need to draw anything here tbh...
im eating lunch at a cafe so no drawing from me
[1]=[92]={1,92}
[2]=[91]={2,91}
I dont follow
the ideal is to write all classes without redundancy
Focus on the question I've just asked
equivalence class of 90
Right]
when listing representatives we should ignore those that give redundant classes
one goes up the other goes down
if we have 1 then we exclude 92
this pattern, up until what number?
So we can keep going
you should figure that number out
[1] = [92]
[2] = [91]
[3] = [90]
...
What's the last equivalence class?
but thats the right question
dude this is so hard
last equivalence class is [92]=[1] but that's already included so since it's repeated we don't count it
this is a combinatorics question dude
can somebody help me
maybe doing a drawing can help
maybe itll be easier if you think this way
list all representatives then remove redundant ones
yes
something like this dude?
[45] = [48] = {45,48}
[46] = [47] = {46,47}
so the number of equivalence classes is 1 to 46
yes
because then [47] = [46]
the classes without redundancy are [1],β¦,[46]
So how many are there?
yes, but how many classes are those?
Brother....
(46+1)Γ47/2
Those ARE the classes
Suppose you had a school, with classes numbered 1 to 46
How many classes does the school have?
46 classes dude
There we go
What is this for, then?
I thought 1 doesn't count
Why?
or that we were overcounting
the number of classes is the number of representatives without redundancy
thats as simple as it gets
yes, is tricky dude
np 
.solved
Closed by @tidal turret
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
for an infinite sequence of the digits of the positive integers that goes like this:
1234567891011121314151617181920.....
I am given an integer K, such that I take the first K digits of the sequence and discard the rest of the sequence
Is there a way to calculate the sum of the K digits without brute force.
I successfully found the sequence of the sum of the first K digits for that sequence on OEIS but it didn't contain any formula that I may use to find its value. Here it is https://oeis.org/A054632
@lethal owl Has your question been resolved?
well there are of course much better ways than just straight up bruteforce
but still not a nice closed formula
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
If you see the series as
00 01 02 03.. 09 10 11 12 ...
then sum of first k digits is given by
https://py3.codeskulptor.org/#user310_oIXwFakrOz_4.py
you can see it works
You can also find a formula for the exact series but I changed the starting to make it look clean
Browser-based Python development environment.
Very off topic, but pfp source?
Xie Yan from Evil God manhua
how to deal with trignometeric function of jee
!occupied
Someone else is already using this help channel. If you need help with a question, please open your own help channel/thread (see #βhow-to-get-help for instructions).
.close
Closed by @vocal raft
Use .reopen if this was a mistake.
if only there was a single answer lol
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Bob and Sasha are brother and sister. Bob has as many brothers as sisters, and Sasha has twice as many brothers as sisters. How many boys and girls are there in this family?
how would u set this as a matrix
i got the answer but i want to see the math way of doing it instead of just picturing it in my head
let b be the number of boys including Bob, and g be the number of girls including Sasha.
then there are b-1 boys besides Bob and g-1 girls besides Sasha.
Bob's brothers = ?
Bob's sisters = ?
Sasha's brothers = ?
Sasha's sisters = ?
write these down in terms of the variables b and g, then form two equations
@chrome swift Has your question been resolved?
Closed by @chrome swift
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
I'm trying to provide a combinatoral argument for $\binom{n}{r}= \binom{n}{r,n-r}$
wai
I was thinking I could just say to select r objects from n objects we can either select r people from n people or divide n people into two groups, r of whom we select, n-r which we don't
does that work
yea
Closed by @twilit field
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
how do i plot a quadratic graph on desmos when i'm only given the solutions?
i feel like thatd take too much time given that a is an integer greater than 1
so it wont just be (x-7)(x+3)
hm
it'll be a times that
Closed by @lucid delta
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Channel closed due to the original message being deleted.
If you did not intend to do this, please open a new help channel,
as this action is irreversible, and this channel may abruptly lock.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Help please
How do I know
what's the derivative of a constant
0
Also notice each vector has the form (x,y)' = (1,y')
I donβt understand
The arrows of your slope field are vectors
You have 4 possible solutions which are all constant. Your job is to figure at which value of y (see the vertical axis) do you have the vector (1,0) for all x
Um
We not taught that we are taught to draw the possible slopes following the lines and guess y (x) so I donβt know what this means
So itβs -1 and 2??
Oh ok and since 2 is not option itβs -1
yes
Ok thank you
@rugged thunder Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
There is a one-to-one correspondence between any two right cosets of H in G.
I don't get this, by definition isn't the coset for a given subgroup unique?
$Ha ={ha \mid h\in H}; a \in G$
wai
oh, $a$ varies
wai
.close
Closed by @twilit field
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
hey
i dont get it how am i still wrong
pls just point out my mistake cuz im lost
<@&286206848099549185>
row 2's leading entry is a 4, not a 1
leading entry in row 2 is further right than that in row 3
column 4 has a confusing pivot situation - if it has a pivot, then the rest of the column isn't 0
two different rows have the same column as their leading entries (2 and 4)
The owner is missing!
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
wait
list down the conditions for RREF
it's an augmented matrix btw
ok
1.) the bottom row should be all zeros (if it can)
2.) there should be a staircase pattern going southeast for every leading entry
3.) everything below a leading entry should be 0
RREF:
4.) all leading entries are 1
5.) column with a leading entry should only have the non-zero leading entry (1) and everything else in the column is 0
lmk if im wrong
no it's an augmented matrix
and you forgot one extra rule - each column can only have one leading entry or pivot
that's rule 2
i'm pretty sure the same rules apply to an augmented matrix. and btw, the word augmented is in brackets
ah seriouesly?
in that case, rows 2 and 4 together break rule 2
ok that might help

but im not tryna have a pivot on every row
or column
you have the wonderful option of zeroing out one row at the bottom and then you now have 3 rows and 4 columns to work with
so definitely one of the columns won't have a pivot
@chrome swift Has your question been resolved?
Closed by @chrome swift
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Whats your progress so far?
dont know how to start dude
Well, do you have the definition of a function?
ok so for the first one, can you find anything wrong with it?
or not
maybe its correct
What you know is that a function gives each starting value a unique outcome
maybe the function doesnt obey that?
ok jaja
the starting values are 1,2,3,4,5
here you have 1 -> a and 2->a which isnt a problem
You would have a problem if lets say for example you have:
4 -> b And 4 -> c
because then 4 would be given two different values which you dont want
3 R a, 3 R d
(it isnt problematic that two different starting values go to the same thing)
its not a function
why?
5 isnt mapped to anything
1 R a and 2 R a implies 1 = 2
no
its the same as before you can have two things that are mapped to the same thing
what you dont want is one thing to be mapped to two different things
true!! i keep forgetting hahaha
You can for example think of the function for all x in N, f(x) = 0
everything is mapped to 0, but thats not a problem
so whats your verdict for the 3rd one then?
its a function
oof dude
it is quite a big jump in difficulty
it may seem like it, but if you go slowly to verify what you want it should be ok
so first of all, is everything in A mapped to something?
3 = 2b - a
sure
Renato si quieres ayuda en espaΓ±ol, me dices.
i prefer to keep it in english so thr progress is not lost ykwim
R includes Q, so I think yes
is bad justification but i am convinced
it is unique
why is it?
yes
basically, when you fix your a, you get b
if you know what a is, then you can find b and he is unique
so that's why it works
theres only one b for each a
yesss
why so?
JAJAJAJAJAJA
lol
dude
so funny huh
0 R nothing
huh?
a = 2b - 3
yes
right?
a in R, b in N
indeed
oh thats what you were saying
JAJAJAJAJAJ
yup
they all are mapped to something, but that something isnt always in N, so its cooked essentially
well done
now for the last one
you see its not that complicated if you go slowly :)
a+b|5
you are able to do it
is it a+b | 5 or 5 | a + b?
im not that fluent in spanish, but i think its the second one no?
latter
wdym
well for example look at the 4th one, (0,0) in NxR but 0 isnt equal to -3
yet we said its a function
(which it is)
do you understand?
im stupidddd
what you said here is that (3,3) isnt in R that defines our function, but we dont really care about that
nah you're good
happens
so any other ideas maybe?
we want to see if everything is mapped to something, and if that something is unique
this is not a function
and why is that?
10 R 0, 10 R 10 => 0 = 10, absurd
dude, it was hard or no?
what do you mean? what was hard?
exercise
depends which level you are
for me it wasnt hard no, but if you asked me 10years ago, the answer wouldnt be the same
i appreciate it dude
my pleasure broski
.solved
Closed by @tidal turret
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
I want to learn proofs without reading a textbook is that possible
Please don't occupy multiple help channels.
.close
Closed by @fallow scarab
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Channel closed due to the original message being deleted.
If you did not intend to do this, please open a new help channel,
as this action is irreversible, and this channel may abruptly lock.
.close
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
"a intersection b complement" is ambiguous
bc you chose to put it into words it's impossible to tell if you meant $A\cap\overline{B}$ or $\overline{A\cap B}$ (also uppercase A and B not lowercase)
Ann
anyway not sure where your confusion is with the pink highlighted stuff
@lunar ridge Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
is ln5?
solution of the ques
are u asking why the limit of that as x->0 is ln 5?
No, but the limit as x -> 0 of that is equal to ln5
then yes
Closed by @oblique heath
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
What is this solenoidal?
and they meant "solenoidal vector field" but somebody swallowed the word "field"
... the wikipedia article lists a definition in the very very beginning
a vector field is solenoidal iff its divergence is 0
Closed by @molten bay
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
here, we need force eqns varying with x
hence integrals must be applied
where
last time you posted this question here i tried to ask you where the integral came up, and you instead decided to run for the hills and close the channel rather than explain your reasoning
hmm
now comprehend it
oh yeah, it was about 5 hours ago that happened
my class was also running simultnaeously so yea
gonna ask for explanation here on what $d\vec{l}$ means and where this formula comes from. if it has a name, i would like to hear that as well so i can look it up myself.
Ann
also once again, how and where EXACTLY does the integral emerge?
@ruby dust Has your question been resolved?
No, because even if there is a force field, nothing is moving along any path in the force field. Integration would give you total work if something did move, but it doesn't. As stated in the problem they're simply measuring the force at each point.
In order to find the force on the paramagnetic ball from the expression for B, I believer you'll need to differentiate the flux density.
elaborate
Not unless you can ask a more specific question -- or perhaps answer Ann's clarifying question about what you want to integrate and why.
@ruby dust Has your question been resolved?
ahem.
will try to do it myself @dusk furnace @lyric charm
will report when i face a issue
.close
Closed by @ruby dust
Use .reopen if this was a mistake.
??
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
3.i.c
for c i get a not nice quartic
and idk how im gonna simplify it
i get
(k - (36/(k-36/(k-36/(k-36/2)))) = 2
(k - (36/(k-36/(k-36/(k-18)))) = 2
(k - (36/(k-36/(k-36/(k-18)))) = 2
k(k-18) - (36/(k-36/(k-36))) = 2k - 36
k(k-18)(k-36) - (36/(k-36)) = (2k-36)(k-36)
k(k-18)(k-36)(k-36) - (36) = (2k-36)(k-36)(k-36)
k(k-18)(k-36)(k-36) - (36) = (2k-36)(k-36)(k-36)
k(k-18)(k-36)(k-36) - (36) = (2k-36)(k-36)(k-36)
did you solve the cases of periods 1 and 2
these will also appear as roots of this quartic
wdym
as in (k-36)^2 instead of (k-36)(k-36)
that sort of thing?
even then idk what to do with the extra 36
i mean expanded form
@jade magnet Has your question been resolved?
could you show what you mean
yea
can you tell me what the k values were for constant and period 2 btw
Closed due to timeout
Use .reopen if this was a mistake.
for the constant it was 20 iirc
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
welp now we have to reopen it in my name ig
yeah why does this keep timing out
you didn't click on bot's prompt
right here
anyway this is what i came up with
this factors quite nicely
eh thought u need help for the first time
got exited for nothing
yeah nope
wait did it?
oh yeah
true
idk why i got 30 something first time
@jade magnet anything else or can i close this now
aight fuck it im closing. @jade magnet when you come back you can ping me in like #precalculus or sth about this if you still need me to yap
nope
.close
Closed by @lyric charm
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
are you stuck on a or b?
@wanton grove Has your question been resolved?
for a it is the same k
Closed by @wanton grove
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
whats the motivation of inducting on 2^m?
what is the step before the win state?
personally, i would put it in binary and that almost trivializes the problem
ohh
wait binary?
yes, that or consider v2(p) and v2(q) and the v2 of the resulting piles
[Another hint for the motivation might have been that 64 = 2^6]
[Not a definitive hint, it doesn't really explain why you should think that to be helpful, but it gives you a road you can try driving into]
oh we're looking for motivation
i kinda sidetracked myself to solving the problem whoops
I mean the solution is there lol
yeah
how would you even do this in binary
Though putting it into binary, if you can do it properly, is an interesting approach
Well, if you add two numbers in binary, say P + Q
Wherever there's a 0 in Q, the total in that column's just whatever's in P
If there's a 1 in Q, then the total's gonna just be 1 if the column in P is 0, or 10 (where the 1 is pushed left) if the column in P is 1
[Honestly it's a messy explanation even if trivial]
oh no wait, one pile becomes P-Q and the other is 2Q
2Q is simple - you just add a zero to the right of whatever v2(Q) is
For P-Q, ... er...
well shiet idk how to explain that one chief
isnt vp(Q) a function for the power of the prime p that still divides Q?
ideally you want each move to be somewhat βconstructiveβ, so hopefully P-Q also increases the v2
(Honestly I've never seen this notation, I thought it was the binary rep. of Q)
that motivates how you structure your moves
ooh wait
If you can keep increasing the v2 of every pile, you have to eventually get 2^6
(doesn't this decrease the v2?)
er it shouldnβt if you make good choices
e.g if we do 3 and 7, we get 6 and 4, increasing the v2 of both
is it like there are an even number of the things that have the last digit of 1 in the binary rep of the piles, so you can do the move on all of them and v2 of P-Q will increase, so every term is divisible by 2
you keep identifying piles that share their βlowest active bitβ, and then your transfer eliminates that bit in both
after doing it theres also an even number of things with the second last digit of 1 and you can do them, so every term is divisible by 4
and you can repeat this?
Yes exactly and this is precisely because we know the piles sum to a power of 2
ohhhh
actually this is like really simmilar to the solution here, this used induction and we used an algorithm of sort?
(Also just to clarify, vp(n) is just the highest exponent x such that p^x divides n, itβs just the power in the prime factorization)
yeah any (good) inductive problem is really just an algorithm in disguise
Which equals the number of digits in base p, minus 1?
moreso the position of the last nonzero digit
12's binary representation is 1100, so v_2(12)=2
yee
vp is just a funny way of saying βweβre a multiple of this power now yayβ
Closed by @viral dagger
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Can you provide the uncut question?
a^2 + 2ab + b^2
I assume they are expanding the first bracket rn
Cuz 2(4)(5) =40 :/
yep
so its a perfect square?
it's just from this
= (5x + 4)(5x + 4)
= 5x(5x+4) + 4(5x + 4)
You should probably be able to see the rest of that expansion
i didnt think you did all that. i thought it was 5x^2 and 4^2 and youre done
In general it is NOT the case that $(a+b)^2 = a^2 + b^2$.
Waes (Wires)
(5x+4)Β² = 25xΒ² + 2*5*4x +16 -15x - 12 +1
2*5*4x = 40x, so I suppose you paused the video before they had time to put down the -15x.
You should be familiar with this being the expansion
$(ax +b)^2 = a^2x^2 + 2abx + b^2$
MΓ©dicis
when is it the case
in $\mathbb{R}$, only when $a = 0$ or $b=0$.
MΓ©dicis
My point is, this isn't a valid expansion of the brackets
Break it up like so, and you're far less likely to make that mistake
@polar pulsar Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Limit n tends to 0
e^(1/(nlogn))
limit ( x ) tends to 0 ( e^{\frac{1}{x \log x}} )
Andy
@molten bay Has your question been resolved?
<@&286206848099549185>
@molten bay Has your question been resolved?
You can take the limit of xlogx separately and then plug it in
its 0 from e^(-\infty)
,w e^(-1/infinity)
@quiet pawn
moon
wait but Andy do you get how to arrive at that
No
,w limit x tends to 0 1/(xlogx)
@mortal falcon @quiet pawn
thats not even the point
Yeah π
I'm talm about this, if it's 0+, then the answer is defined
Rs
Closed by @molten bay
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
!status
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
idk what to do after this
2
f(1) is just 3
you can write your limit as $\exp\paren{\frac13 \lim_{x \to 0} \frac{f(1+x)-f(1)}{x}}$
Ann
hmmmm
this form should be familiar
legrange's theorem
Ann
Closed by @oblique heath
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
A woman has $n$ keys, of which one will open her door
\
If she tries the keys at random discarding those that don't work that's the probability that she will open the door on her kth try
wai
do you mean on or before the k'th try, or do you mean exactly on the k'th try
exactly
so her first k-1 keys need to be wrong and the k'th needs to be right
yes
!status
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
idk if i can give a hint without spoiling the type of distribution this sounds like
you dont need to think about distributions here
op is doing extremely basic probability with explicit counting of favorable vs total outcomes
i see, fair
also the total number of permutations of the keys is n! and not k!
Actually the size of the sample space might be npk and the number of favourible ones would be (k-1)!
actually the word "sample space" might, once again, refer to a SET and not to a NUMBER?
Fixed
what are you considering to be a 'sample' here then
if you're claiming that their count is P(n,k)
I'm thinking the sample space includes the sets of ordered permutations of the k keys
there are n keys not k keys

