#help-39
1 messages · Page 277 of 1
Not yet
oh okok
So that means, h(x) can be rewritten as $x^{\frac{1}{3}} +1$
CaptainNova22
Do you agree?
OH YES
CaptainNova22
Do you understand that?
i understand why its written that way but i dont understand what is next
like yes i understand it but i dont understand what to do with it
So you now, back to the table, you apply the rule $(a^x)^y = a^{xy}$
CaptainNova22
Meaning that h(g(x)) = $(x-1)^{3 \cdot {\frac{1}{3}}} +1$
okok i see
CaptainNova22
Yes
so every time theres a sqrt like that ill do fractional exponent
instead of just needing to distribute
You didn't need to distribute in the first place, you just needed to apply what you know with roots and exponents and simplify
right right
is the winter math homework hitting rn 😂
seems like you've been here all day without break
who me..😅
yeah hahaha
im preparing for college i haven’t ever been good with math loll
so im trying to quickly learn everything to college standard at least
So when it was asking to do h(g(x)), you started it off fine by plugging g(x) into h(x), it was just then applying the mathematical concepts to simplify it
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fair, best of luck!
if you keep working hard you'll get there in no time :)
hehe thank youuu!!! 
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for part by I can find that it is <= (b-a)^2 by saying that int_a^b f(x)dx <= f(b)(b-a) but I cannot figure out how to get the 1/2 there
what is this supposed to be? why is there an extra x at the end?
yes please
$=| \int_{a}^{b}(f(x)-f(a))dx| \leq \int_{a}^{b} |f(x)-f(a)|dx \leq \int_{a}^{b}(x-a)dx=\frac{(b-a)^{2}}{2}$
Cogwheels of the mind
two question. First how did we even go from $|\int_a^b f(x)dx - (b-a)f(a)|$ to what you have. And second how can $\int_a^b (x-a)dx = \frac{(b-a)^2}{2}$ would it not be $\frac{(b-a)^2}{2} - ba -a^2$
BigBen
but if you make that sub you forget (b-a)
$\int_{a}^{b} (x-a)dx= \int_{a}^{b}(x-a)d(x-a)= \int_{0}^{b-a}ydy=\frac{(b-a)^{2}}{2}$
Cogwheels of the mind
I forgot nothing
I don't see where our b-a goes in the sub of g(x) = f(x)-f(a)
I don’t see how bound becomes an issue
I am out
Oh I left out your first question
$|\int_{a}^{b}f(x)dx-(b-a)f(a)|= |\int_{a}^{b}f(x)dx-\int_{a}^{b}f(a)dx|=|\int_{a}^{b}(f(x)-f(a))dx| \leq \int_{a}^{b} |f(x)-f(a)|dx \leq \int_{a}^{b}(x-a)dx=\frac{(b-a)^{2}}{2}$
Cogwheels of the mind
I thought it’s obvious to you
I missed that
how are we allowed to do this with the differential? what is the motivation? Also I don't see where we have y = x
y=x-a
why?
ok then we have dy/dx = x and then we wouldl need xdx
$\int_{a}^{b}(x-a)dx=\frac{x^{2}}{2}-ax |_{a}^{b}=(\frac{b^{2}}{2}-ab)-(\frac{a^{2}}{2}-a^{2})= \frac{(b-a)^{2}}{2}$
I was thinking about it in terms of the expansion of an interval property
Cogwheels of the mind
Though I prefer this
I really don’t understand how it becomes an issue. Maybe get used to substitute
for your sub part how did you get dx = d(x-a)
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Chat is this real
spam alert
xD
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@stable dune
it's a corollary of lagrange's theorem
what's your definition of the order of an element?
Oh I lowkey thought they wouldn't even be able to use lagrange
The proof would essentially be proving Lagrange anyways I suppose
oh, you can't use it?
order of a element mean if we increase power of it we get identity of that group
The least power
The least positive power yes
So
What can you say about the subgroup generated by that element
<x>
What is in it? How many elements?
how many elements are in <x> ?
Well yes that's essentially the question
When we asked how many elements are in a set
Yes
yes, the order of <x> is the order of x
|<x>| = o(x)
I see
So
What does Lagrange say
<x> is a subgroup
We are looking at the set of all possible powers of x
i meant subgroup is like we need identity and a element?
(can you use lagrange for this question?)
It makes a subgroup
I guess no
Really?
we will try to see...via example)
They didn't mention it actually
well by definition <x> contains the identity 1
since the elements are powers of x then <x> is closed under multiplication
<x> is just all integer powers of x
The inverse of x^n is x^(-n)
Still a power of x
@fading ledge given a group G and an element x of G, <x>:= {e,x,x^2,...,x^{n-1}} where e is the identity element and n is the order of x
probably your book already proved that <x> is a subgroup
And the product of two powers of x is still a power of x
now if you want prove that this is in fact a subgroup of G, or just take it for granted if you feel like its obvious to you
so we know <x> is a subgroup from all this above
what can we say about the cosets of <x>
anyways, since you cant use lagrange then you can prove it if you want
Left cosets?
yeah
and then the result you are looking for will follow
okay so left cosets we will have like all the elements which multiply by x left side
i would say you can use lagrange if it's stated in the book prior to this question
likely a question like this comes after proving lagrange anyway
I see
hmmmm i am not sure what exactly you mean by this but if i understood you correctly then not quite
can you write what that means using some symbols?
but what you are looking to prove is that ||the cosets partition the group and are of the same cardinality, so the order of the subgroup divides the order of the group exactly by the number of cosets it has in the group||
right so what are the cosets of <x> in this case?
Number of elements in group G?
no i meant to use this notation
I think at this point we're into the proof of lagrange theorem
Are you sure Lagrange theorem isn't before this in your book
you should check
Ohh wait
assuming you're using a textbook
Lagrange is immediate from properties of cosets anyways
Cosets have same order + partition G
I see
That's true
So what does it prove?
for a subgroup H < G, there are [G : H] cosets. the cosets partition G and have order |H|. so |G| = [G : H] * |H|.
Well if <x> has an order which divides G by Lagrange
And the order of x is the order of <x>
Then what can we say
side note: you could generalize more and say that given a group G and 2 subgroups H and K such that K\subset H, its true that (G:K)=(G:H)(H:K)
<@&268886789983436800> crypto spam :(
@fading ledge Has your question been resolved?
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Hi
Let f be a twice continuously differentiable real-valued function on an open interval containing 0 such that f(0) = 0 and f′(0) = 1. Suppose f satisfies the equation
f(x) = integral from 0 to x of e^(x − t) · (f(t))^2 dt for all x in its domain.
Prove that f is uniquely determined, find an explicit expression for f(x), and determine the maximal interval on which this solution exists.
Can anyone solve it with proper solution
<@&286206848099549185>
I’ll try
me too
what have you tried
Yes
?
Got maximum interval
(-infinite,0)
f(x)=?
No
@surreal siren
Are you Bhartiya?
Jä
!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
Ya
How to find f(x)
Me also
Cool
Operate our language
try using leibniz's rule
Yes
!noanswer
The purpose of this server is to help you learn; please don't ask for direct answers. Ask for guidance, explanations, or feedback instead.
Leibritz theorem use karna padega
Kya aya expression
Check karta hu
Differentiate the equation using Leibniz rule to get f′(x) = f(x) + (f(x))²
2. Solve the ODE to get f(x) = e^x / (1 − e^x), valid for x < 0
F(0) = 0 nahi aaraha hai
Undefined hoga
Lim lagaoge toh infi ayega
Kese?
F(x)=0
?
Uska slope zero hoga
Phir f’(0)=0 ayega
Differentiate karle equation using Leibniz rule to get f′(x) = f(x) + (f(x))²
Use the initial condition f(0) = 0; the only solution to f′ = f + f² with f(0) = 0 is f(x) ≡ 0.
Leibniz check karo
Writing op
Sahi hai
Isme leibniz se f(0)=0 nahi aana chahiye
But possible nahi hai kyuki for constant function slope always zero ayega
Toh f’(0)=1 satisfy nahi ho raha hai
Hai possible
At x = 0, the integral is zero, so f(0) = 0
Differentiate the equation using Leibniz rule to get f′(x) = f(x) + (f(x))²
At x = 0, f′(0) = 0 because f(0) = 0
The only solution to f′ = f + f² with f(0) = 0 is f(x) = 0 for all x
Yeh dekh bro
But question mein f’(0)=1 Diya hai
Aap idhar f’(0)=0 le rahe ho
Then there is no sol
Because f'(0)= 1 and f'(0) = 0 simultaneously
No solution
Not defined
Also
Maximum interval
@surreal siren
Ha no solution hi hoga I think
Karliya
Bruh yeh college ka question hai
Kyu
Odisha
Ek aur bar
Jai Jagannath
Kisi aur se puch lo
Yes
Jai rajputana
CBSE board
Hm
Yes
Goodnight brother
Kyu
Neend aarahi
1 question karlo
sin²x + tan²x=?
Iska kya karu?
Kya hota hai
Nahi
Ha par koi options?
sin²x + tan²x = sin²x+sec²x-1=sin²x-sin²x-cos²x+sec²x
Ek simplification
= (secx+cosx)(secx -Cosx)
.
Options par depend karta hai
.Gn
Yes
Gn
.Gn.
!closed
Good night brother
.close
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ive never seen a problem like it
<@&268886789983436800>
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guh guh guh
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im just wondering why this only works for non integer values of p?
and what would we do for integer values?? would there be a new defined function and what would the GS look like
holy periodhater he/him
yes i am
i also read feminist literature and drink matcha instead of water
are u also 6ft2
i hope some kind lady helps this saint
no no ladies have too much on their plate already
i wouldnt dare bother them
jokes aside tho any help would be appreciated
@real arrow Has your question been resolved?
i might be trolling
but
do jp and j-p have to be linearly independent
i plugged in 2 and -2 for p in 4.37 and got the same thing
so maybe thats why
yes your right
im not sure about the GS
for integers
im pretty sure jp would be in it still because the recurrence relation is still fine
j-p would break the recurrence
i dont know what the other part of the GS would be
would i just use this to find the other one
i think it will give it to me
if i use jp
i checked p=1 and got Jp = - J-p
so it might be that J-p = (-1)^p Jp for p non negative integers so theyre not linearly independent
yea
i found out that its not linearly independent for integers
so i was wondering what the actual GS would be
im pretty sure it would be jp(x) + some other function (x)
jp(x) would still be present but obviously j-p(x) would be something else for integers
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✅ Original question: #help-39 message
so im thinking that we use this to find the other part of the GS
yayyy
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maybe u can also do reduction of order stuff like y_2 = u(x)y_1(x)
maybe thats how theyre getting that fmla
yea i probably could as well
oh wait the picture i sent is from reduction of order xd
omg fire
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!done
If you are done with this channel, please mark your problem as solved by typing .close
do you have a question?
Yah wait i have one
@crystal dew
Can you help me

you have accurately described my response to your question
so do you have a proper question or shall I close this
and ofc, please do not troll in help channels.
Noi i am high schooler
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Why there is my channel
I didn't open it
because you typed something in an open channel
Oh
now, off to #discussion if you want to talk further
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Observe how the numbers change in this sequence.
Using the convention of starting with $a_0 = 1$, we have $a_n = a_{n-1} + 1$ for $n \in \{1, 3, 6, 10, \dots\}$ (and $a_n = a_{n-1}$ otherwise), the well-known series $S(i) = \sum_{i=1}^ki$.
In other words, the given sequence is constructed by writing $k+1$ until $n = S(k)$.
So we write $a_{\ceil{S(k)}} = k + 1$.
We need to solve $n = S(k)$ for $k$ to determine a formula for $a_n$.
\begin{align*}
n &= \sum_{i=1}^ki \\
n &= \frac{k(k-1)}{2} \\
2n &= k(k-1) \\
k^2 - k - 2n &= 0 \\
k &= \frac{1 \pm \sqrt{1 + 16n}}{2} \\
k &\approx \frac{1}{2} + 2\sqrt{n}
\end{align*}
using only the positive root.
Coolempire2026
Was working to construct a proof for this by solving backwards but
My formula is slightly off
Oh
I see what happened
Observe how the numbers change in this sequence.
Using the convention of starting with $a_0 = 1$, we have $a_n = a_{n-1} + 1$ for $n \in \{1, 3, 6, 10, \dots\}$ (and $a_n = a_{n-1}$ otherwise), the well-known series $S(i) = \sum_{i=1}^ki$.
In other words, the given sequence is constructed by writing $k+1$ until $n = S(k)$.
So we write $a_{\ceil{S(k)}} = k + 1$.
We need to solve $n = S(k)$ for $k$ to determine a formula for $a_n$.
\begin{align*}
n &= \sum_{i=1}^ki \\
n &= \frac{k(k-1)}{2} \\
2n &= k(k-1) \\
k^2 - k - 2n &= 0 \\
k &= \frac{1 \pm \sqrt{1 + 8n}}{2} \\
k &\approx \frac{1}{2} + \sqrt{2n}
\end{align*}
using only the positive root.
Coolempire2026
Applied the quadratic formula wrong
Okay now my question is how to turn this from observations into a proof
In reality n = ceil(S(k)) so we actually have
$0 \leq k^2 - k - 2n \leq 2$
Coolempire2026
Any help would be appreciated!
Slight error - should be writting k* until n = S(k) [and starting the next number, k+1, exactly when n = S(k)
With this in mind, the observations become
Ah I just realized that ceil(S(k)) doesn't even make sense since it's an integer always 😂
It should be
yea i was going to tell you that
S(k-1) <= n < S(k)
but also i am not really sure i understand what you are saying here tbh
it might be me being stupid rn
Did you read the image with the sequence
You mean the sentence that has the incorrect notation? or the whole paragraph
starting from "the well known series" up to and excluding the beginning of the calculations
I just followed the textbook's way of writing
'constructed by' and then the procedure
Observe how the numbers change in this sequence.
Using the convention of starting with $a_0 = 1$, we have $a_n = a_{n-1} + 1$ for $n \in \{1, 3, 6, 10, \dots\}$ (and $a_n = a_{n-1}$ otherwise), the well-known series $S(i) = \sum_{i=1}^ki$.
In other words, the given sequence is constructed by writing $k$ until $n = S(k)$.
So we write $a_{S(k-1) \leq n < S(k)} = k$.
We need to solve $n = S(k-1)$ and $n < S(k)$ for $k$ to determine a formula for $a_n$.
Coolempire2026
So it would be interpreted as
a0 = 1
S(1) = 1
S(2) = 3
So for n in [1,3) we write a_n = 2
S(2) = 3
S(3) = 6
So for n in [3,6) we write a_n = 3
S(3) = 6
S(4) = 10
So for n in [6,10) we write a_n = 4
We can see how this gives us the original sequence
1 entry (0) includes 1, 2 entries (1 and 2) include 2, 3 entries (3, 4, 5) include 3, 4 entries (6, 7, 8 and 9) include 4
And so on
hmmm i see what you are saying
,w solve (x-1)(x-2)=2n
Hmm what did they do with the b^2 term that turned into a 9
Ah
8(n-1)
ofc
Observe how the numbers change in this sequence.
Using the convention of starting with $a_0 = 1$, we have $a_n = a_{n-1} + 1$ for $n \in \{1, 3, 6, 10, \dots\}$ (and $a_n = a_{n-1}$ otherwise), the well-known series $S(i) = \sum_{i=1}^ki$.
In other words, the given sequence is constructed by writing $k$ until $n = S(k)$.
So we write $a_{S(k-1) \leq n < S(k)} = k$.
We need to solve $n = S(k-1)$ and $n < S(k)$ for $k$ to determine a formula for $a_n$.
\begin{align*}
n &\geq \sum_{i=1}^(k-1)i \\
n &\geq \frac{(k-1)(k-2)}{2} \\
2n &\geq k^2 - 3k + 2 \\
k^2 - 3k - 2n + 2 &\leq 0 \\
0 \leq k &\leq \frac{3 \pm \sqrt{9 + 8(n-1)}}{2} \\
0 \leq k &\leq \frac{3 \pm \sqrt{1 + 8n}}{2} \\
0 \leq k &\approx \frac{3}{2} + \sqrt{2n}
\end{align*}
using only the positive root.
Coolempire2026
coolemplud
no
And then comes the S(k) root
Hiiiii
I guess I'll leave it in the unsimplified form because the S(k) gives
i feel like i did this problem a long time ago
Observe how the numbers change in this sequence.
Using the convention of starting with $a_0 = 1$, we have $a_n = a_{n-1} + 1$ for $n \in \{1, 3, 6, 10, \dots\}$ (and $a_n = a_{n-1}$ otherwise), the well-known series $S(i) = \sum_{i=1}^ki$.
In other words, the given sequence is constructed by writing $k$ until $n = S(k)$.
So we write $a_{S(k-1) \leq n < S(k)} = k$.
We need to solve $n = S(k-1)$ and $n < S(k)$ for $k$ to determine a formula for $a_n$.
\begin{align*}
n &\geq \sum_{i=1}^(k-1)i \\
n &\geq \frac{(k-1)(k-2)}{2} \\
2n &\geq k^2 - 3k + 2 \\
k^2 - 3k - 2n + 2 &\leq 0 \\
0 \leq k &\leq \frac{3 \pm \sqrt{9 + 8(n-1)}}{2} \\
0 \leq k &\leq \frac{3 + \sqrt{1 + 8n}}{2}
\end{align*}
and
\begin{align*}
n &< \sum_{i=1}^ki \\
n &< \frac{k(k-1)}{2} \\
2n &< k(k-1) \\
k^2 - k - 2n &> 0 \\
k &> \frac{1 \pm \sqrt{1 + 8n}}{2} \\
k &> \frac{1 + \sqrt{1 + 8n}}{2}
\end{align*}
using only the positive roots.
Coolempire2026
What did I do wrong 👀
nvm its just me hallucinating at 1:20 AM
yea
yea its fine
Observe how the numbers change in this sequence.
Using the convention of starting with $a_0 = 1$, we have $a_n = a_{n-1} + 1$ for $n \in \{1, 3, 6, 10, \dots\}$ (and $a_n = a_{n-1}$ otherwise), the well-known series $S(i) = \sum_{i=1}^ki$.
In other words, the given sequence is constructed by writing $k$ until $n = S(k)$.
So we write $a_{S(k-1) \leq n < S(k)} = k$.
We need to solve $n = S(k-1)$ and $n < S(k)$ for $k$ to determine a formula for $a_n$.
\begin{align*}
n &\geq \sum_{i=1}^(k-1)i \\
n &\geq \frac{(k-1)(k-2)}{2} \\
2n &\geq k^2 - 3k + 2 \\
k^2 - 3k - 2n + 2 &\leq 0 \\
0 \leq k &\leq \frac{3 \pm \sqrt{9 + 8(n-1)}}{2} \\
0 \leq k &\leq \frac{3 + \sqrt{1 + 8n}}{2}
\end{align*}
and
\begin{align*}
n &< \sum_{i=1}^ki \\
n &< \frac{k(k-1)}{2} \\
2n &< k(k-1) \\
k^2 - k - 2n &> 0 \\
k &> \frac{1 \pm \sqrt{1 + 8n}}{2} \\
k &> \frac{1 + \sqrt{1 + 8n}}{2}
\end{align*}
using only the positive roots.
Thus we have
\begin{equation*}
\frac{1 + \sqrt{1 + 8n}}{2} < k \leq \frac{3 + \sqrt{1 + 8n}}{2} = \frac{1 + \sqrt{1 + 8n}}{2}
\end{equation*}
That is, that $k = \floor{\frac{1 + \sqrt{1 + 8n}}{2}} \approx \floor{\frac{1}{2} + \sqrt{2n}}$.
I don't have an equation environment?
wtf
No I put begin at the end
Coolempire2026
So now I have that $a_n \approx \floor{\frac{1}{2} + \sqrt{2n}}$
Coolempire2026
Showing that they are equal is beyond me thoug
So now that's my new question 🙂
And then how to formalize this compendium of observations
this is so cursed
you've observed that it's sufficient to find where each sequence increases by 1, right
a_n and floor(1/2 + sqrt(2n))
something here must be wrong in the inequalities
probably not the calculation itself but what you were calculating to begin with
because $\frac{1+\sqrt{1+8n}}2>\frac 12+\sqrt{2n}\geq\floor{\frac 12+\sqrt{2n}}$ so reaching $k>\frac{1+\sqrt{1+8n}}2$ is definitely wrong
for the kth triangular number yeah
ali yassine
so you just need to show that plugging k(k+1)/2 into the sqrt thing gets you k, but plugging in k(k+1)/2 + 1 gets you k+1
ohhh i see, in that case it might work
tbh i am not really able to focus rn so i cant really be very helpful 🥀
sorry vro
I'll try this
This is a lot of work for me to do now
I will have to do it later/tommorow
.close
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So I want to show that $\sum_{i=1}^{\infty} \frac{1}{i}$ diverges using cauchy
Proof: Let the series converge. Then for $\varepsilon= \frac{1}{2}, \exists N \in \N : n,m≥ N \implies \abs{\sum_{i=1}^{m} \frac{1}{i} - \sum_{i=1}^{n} \frac{1}{i}}< \frac{1}{2}$.
Chose $m=2N;n=N$. We then have $\sum_{i=N}^{2N} \frac{1}{i} ≥ N \cdot \frac{1}{2N} = \frac{1}{2}$. This is a contradiction to our assumption that $\sum_{i=1}^{\infty} \frac{1}{i}$ converges.
Thus $\sum_{i=1}^{\infty} \frac{1}{i}$ diverges
oops
wai
You kinda avoid using cauchy anywhere
sum u=N to 2N of 1/i > 1/2 is independent of Cauchy
well, my idea was I show the difference exceeds 1/2 for large enough N
that's basically the difference in cuachy no
Cauchy is more than just about the specific choice of m=2N and n=N
Once you fix m=2N, it's not really using Cauchy anymore
Using Cauchy would be more like any arbitrary m and n greater than some N
Your proof is like 90% contradiction and 10% Cauchy
The question is phrased that you shouldn't be contradicting convergence, but contradicting the sequence is Cauchy
could you show me how that'd work please
https://math.stackexchange.com/questions/2132993/prove-that-a-cauchy-sequence-is-convergent#2133001
Just substitute your actual sequence
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Hi
This is for f(x) = x^2 -2x +2
I completed the square
(x-1)^2 + 1 greater than or equal to 1
but should the final answer be f(x) is greater than or equal to 1
rather than 0
because the minimum value is 1
what is the question
at x=1 for example, f(x) = 0
Why is it f(x) is greater than 0
if anything, the answer should be f(x)≥0
should it be f(x) is greater than equal to 1
I thought the minimum value is 1
so why is the minimum value 1
it isnt
they should say the minimum value f can attain is at 0 and it happens when x=1
okay i realize now
the quadratic is (x-1)^2 + 1
yes?
i thought (incorrectly so) the quadratic in question is (x-1)^2
u r correct, f(x)≥1 is the answer
because its also true
answer sheet is wrong
i mean it is true
but like
im sure the teacher desired u to do f(x)≥1
@timber schooner Has your question been resolved?
Tanks
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When milk freezes, its volume increases by one-fifth.
When the milk melts, by what fraction does its volume decrease?
Please don't occupy multiple help channels.
Ok @pearl pond
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There should be a rangle probably cuz we need to chose 3 points
For x=2 the y is ±√10 and for x = -4 the y is ± 2
Like this we have 6 distinct points
y is a integer tho
so we just have 2 points ??
4 tho
What to do next now?
there are a ton of points
the inequality has an overlap of regions
idk where you got x=-4 coz thats not even in that parabola
I can reject -4
It'll be an ellipse th
make a graph or a rough sketch and see what are the actual regions of intersection
*tho
one is an ellipse, the other is parabola
ye
and X is set of the intersection of the two regions
I'll do it later i should go now
@inland laurel Has your question been resolved?
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how 10080 i think im losing it
So if we want to group the vowels, we treat it as 1 unit
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. That was a quickie
. yeah thanks adhi
you dont need to use a . whena channel is closed
only after this msg appears
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this is all ive done till now
well, λa has to be orthogonal to b-c.
so maybe it's time to calculate $\vec{a} \cdot (\vec{b} - \vec{c})$, for a start.
Ann
oh but why? r.(b-c) = 0 and r=lambda(a) + (b+c) means lambda a orthogonal to b-c?
oh hold on my bad
misread the question
r itself is orthogonal to b-c sorry
not λa
@eager jewel Has your question been resolved?
r-(b+c) is parrallel to a
$$(\vec{r} - (\vec{b} + \vec{c})) \times \vec{a} = \vec{0}$$
oh the cross
Robo_17
yes..
oh ok..do u know how to proceed after this?
.
have you done this
$r \cdot (b-c) = \lambda a \cdot (b-c) + (b+c) \cdot (b-c)$
Ann
cbf to put \vec everywhere but you hopefully get my point
ohh ok thats = 0 from there lambda
yes
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im lost on what to do next, i - 3 both sides and was left with |2x-5| >1
you don't know how why i got the -1?
what's the definition of absolute values
$\abs{A} = \begin{cases}
A \text{ if } A \geq 0\
-A \text{ if } A < 0
\end{cases}$
1 divided by 0 equals Infinity
im confused how u got the -1 and why its < 1
hold up
is this the correct definition
since its -5, it then switches to < ?
no no no no no
you got |2x - 5| > 1
so split into 2 cases: 2x - 5 >= 0 and 2x - 5 < 0
okok so i splitt niow
okay i didnt realize we split alr okay hold up
wait why 0's
since the definition splits into 2 parts, it's best to split our absolute value into 2 cases
what does the definition say
yesyes i understand that part
you split it like that
but its > 1 not < 1
the definition of absolute values
i see the definiton but its not lining up
it will make sense later
??
wdym later
im confused now mane
i cantr learn if i dont know what im doing now
when you split into cases like what im doing here
don't really care about what the question says now
yes but u used 0 not 1 howd you get 0
we split by definition
im still lost sir, the definiton doesnt line up
ma'am, the question says |2x - 5| > 1
not 2x - 5 > 1
wait wait
i get it now but i havent needed to do that any other times
how do ik when?
if its = to 1?
the splitting is just me proving to you
you knew to get 0 bc by definition, but im lost because i didnt need to do it
do i go by definition because its 1?
you want some shortcuts?
nono im just trying to understand when to and not to intergrate it
|A| > c => A < -c or A > c
|A| < c => -c < A < c
these shortcuts can be proved by splitting into cases
which is what i did
thats not what im askigg ut telling me ant splitting right?
okok
wait
i am just explainging badly
now if you want >= or <=, apply the same definition but instead of >, it's >= and instead of <, it's <=
so when i get to |2x-5| >1 i was lost, you told me to go by definiton, did you go by definion because it was > 1 or because you always go by ddefinition at that part
that was because im trying to prove to you
im sorry for the confusion
wait i understand that the next part i split, i just was confused if i missed a part inbetween or not
but when you said next you split
you had 0’s and you go by definition. did you go by definition because its 1?
or because you always automatically follow definition before splitting
again, the splitting is because im trying to explain why this works
but if it's multiple choice like this, you can try to use shortcuts like these
you can use shortcuts like what i said above
okok i see why im confused
can you show me normal way
i dont wanna learn shortcuts if i dont have a basic understanding of it in general
split into 2 cases: $2x - 5 \geq 0$ and $2x - 5 < 0$
1 divided by 0 equals Infinity
bro😭
1 divided by 0 equals Infinity
do i use 0’s because its 1 or because you automatically change then into 0
and $2x - 5 < 1$
1 divided by 0 equals Infinity
but if you use $2x - 5 < 1$, it turns really confusing
1 divided by 0 equals Infinity
When we say positive, then something is greater than 0, else smaller
so i use $2x - 5 \geq 0$ and $2x - 5 < 0$, split by definition is an easier approach
1 divided by 0 equals Infinity
so its 0’s because you just wanted to use them???
yes ik
that doesn’t answer my question tho😭
yeah + it's easier to handle than splitting into other numbers
but what abt the 1
how r you able to just get rid of ut
.
that's when the definition of absolute values come in
if $2x - 5 \geq 0$ then $\abs{2x - 5}$ is just $2x - 5$
1 divided by 0 equals Infinity
boom, first inequality $2x - 5 > 1$ which you can solve it yourself
1 divided by 0 equals Infinity
is that basically not what it just was😭
You should tell her that you subtracted 3 on both sides
after resolving the absolute values
how is it easier now when all you did was change < to >
ik that part but that is skipping parts
no it isn't, because this one is $2x - 5 > 1$ while the question asks for $\abs{2x - 5} > 1$
1 divided by 0 equals Infinity
Skipping parts?
the shortcut
why did i need to do all that 0 stuff when all u did was take away the absolute value
this is what she meant
?
hold on, we also have 1 case left
They aren't really shortcuts,,,
Sorry for interrupting, I saw you had a help channel, so I thought you'd be kinda stressed out
im fine with that
so i have |2x-5| > 1 and i split into 2x-5>1 and 2x-5<-1 right
then just -5 both sides?
ill let you take over the channel
the and is wrong
you get 2x-5>1 or 2x-5<-1
You'd add 5 on both sides, and ig solve the inequalities
BRUH
Under the constraint 2x-5 >= 0 which means x >= 5/2 you try to solve 2x-5 > 1, see which solutions satisfy the constraint
<@&268886789983436800> user id: 423444344037703680
🤦
2x - 5 > 1 and 2x - 5 < -1 seems impossible
because literally no number is > 1 and < -1
so we use or in this case
|x| > c means x > c or x < -c where as |x| < c means -c < x < c which means -c < x and x < c
best way to know if it's an or or an and is to visualize on a number line
in college?
yes
you probably will encounter many other logical operators as well
yeah whatever that means…
||and or not nor xor xnor nand||
basically all of them

nand 
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hey! combinatorics problem here.
Let me put it in google translate
Determine the number of ways to distribute 65 students taking advanced mathematics into three courses, two of which consist of 22 students and one of which consists of 21 students.
@cinder flower
Oh no
hello
Hi
way worse today than ever i've seen
wtf
did that guy get banned or do i need to ping mods still
hm i don’t think that’s the idea here
or maybe it got lost in translation. but i would have expected the course student numbers to already be set
so like, this particular one has 21, this one has 22, this one has 22
not just any one of them can have 21 and the others need to be 22
It just says
but anyway it only affects the answer by multiplying by 3 so we can do it either way
2 of the courses have 22, and one has 2q
21
So im guessing the 21 course can be either of the 3
it’s not totally clear but ok
If it said:
The first one has 22, the second one has 22, and the third one has 21
Then
I'd have left out the *3
this is almost right
ok, we can do it your way that’s fine
Ok
you probably know better than me, understanding the original text
viel glück
actually with your way this looks right
Danke 👍
and actually the difference in the two interpretations is different than a factor of 3
with your way you are right
i meant with my proposed interpretation, the answer would not just be 3x more
yea
Kk
So why did you say my solution was almost correct?
Oh you said its correct
I saw now
if the courses are distinguishable and any two of them can have 22 students, your answer is correct
i cannot confirm 100% that is the intended interpretation
okok
well, this interpretation makes the most sense to me
so i'll take it
thank you layla
i do not feel very helpful but no problemo
bro stop stalking the channel 
i guess it would be actually since the courses are (i presume) distinguishable
well
halo
here we go...
you are so pretty
fr
and that origami
magnificent
Wait why is 43 choose 22 = 43 choose 21
But 65 choose 22 != 65 choose 21
huh where'd my messages go 😭
nah bro this has to be a simulation or sum
chose 21 in 65
chose 22 in 44
and its just it
but i could also choose 22 in 65 and 22 in 43
say you have 43 blank marbles. you will paint 22 of them black and the rest white. how many ways to do that? you could choose 22 out 43 marbles to be black. that’s the same same as choosing 21 marbles to be white
yeah and its the same result
omg
any discussion room in this server guys?
yes
but why is this the case?
oh
yeah i see
cuz 22 + 21 is not 65
yea
nice
there’s a saying that goes something like



