#help-49
1 messages · Page 226 of 1
Does this question make sense?
"the sum of value of n"?
the sum of all possible values of n, by the looks of it
of which there is only a finite amount here
I guess finite is one word for it
@barren wharf Has your question been resolved?
Help is needed.
I think the question is not valid
by focusing on triangles ABE and ACD we get that <B+<E=<C+<D=180-alpha
If it could be said that AED is isosceles, there could be a way
by focusing on triangles ABD and ACE we get that <B+<D=<C+<E=180-(alpha+beta)
summing both equations gives us:
(<B+<E)+(<B+<D)=(<C+<D)+(<C+<E)
2(<B)+<E+<D=2(<C)+<D+<E
2(<B)=2(<C)
<B=<C
so triangle ABC should be isosceles but AB≠AC
You're taking <E = <BEA and <E = <CEA (same with <D), of course you're getting a contradiction
ohh mb
@barren wharf Has your question been resolved?
I feel like the expected solution uses trigonometry in some hidden way, like a theorem that's proven using trigonometry or something
Yes, that is what I want.
Not necessarily, of course.
<@&286206848099549185>
@barren wharf Has your question been resolved?
<@&286206848099549185>
What is the problem?
!!!!!
I think you have to use the theorem of cosine for express AD in function of the angle alpha plus beta with the triangle ABD and then express AD in function of the angle alpha for the triangle ACD. In this way you can obtain the value of beta, becouse you know the value of cos alpha and of alpha by AC and AH (where H Is the projection of A on BC)
I think this uses trigonometry.
Yes and you only need two formulas:
- a square + b square - abcosalpha = c square
- cos alpha = side adjacent to the angle on the hypotenuse
When you have obtain the angle alpha plus beta, you had to use another time the theorem of cosine to obtein AD from the triangle ABD and whit AH find HD. Now you use another time the theorem of cosine on ACE and find AE, with AE and AH you find EH, and with EH and HD you find the ED and also the result.
you missed a 2 & also use ^ for exponents. a^2 + b^2 - 2 ab cos(gamma) = c^2
isnt it clearly stated to NOT use trigo?
yes sorry
ah oh my god I didnt see that
so in this question, we can consider there are 3 unknowns, ED, AE, AD
using stewarts theorem in ABD and AEC we can get 2 equations
we just need a third
for this question, i think we can use the property that for convex polygons all angles are less than 180 degrees
so (sum of total interior angles - 3 x 60) / (number of remaining angles) < 180
this will give maximum value for n, and the minimum can be found by observation
I think we can frame the solution as using similar triangles only. Because these formulas don't involve compound angles and only simple ratios.
I think Is a good idea but i not so simple
I m trying to think on it
ive been trying this for 15 minutes but havent gotten anywhere
maybe try constructing angle bisectors or using isogonal conjugates?
Where is the OP?
Pins?
I think I understand how it's done, but I need to rework it rigorously: I imagined that by setting BC fixed and perimeter constant, as an angle theta varies, the position of the intersection point P between BC and the bisector varies. A generic formula for the bisector theorem can therefore be derived by setting BP equal to x and CP equal to x-15. The relationship should allow me to arrive at the result, but I need to verify.
This method should work, I don t know if there Is an easyer one, but now I can try to express it in a good form
@barren wharf Has your question been resolved?
The reasoning I had previously proposed had proven too complicated: nevertheless, I did some research and found that it is easily solvable using a simple theorem that was needed to know. The isogonal theorem states that if two lines AD and AE starting from the vertex A of a triangle ABC and intersecting the opposite side BC at D and E respectively are isogonal, then the following relationship holds: BE.CD/CE.BD=AB^2 /AC^2. In your case by this you find the relationship between BE and CE. Take now BE = x and CE = y. You have 392x=507y and x+y=15, this implies that x=BE= 8,46, so ED=9-8,64=0,36. This implies p=9,8 approximately.
My original idea was to find a direct relationship between ED and side AB (as it varies) with a fixed base BC and a constant perimeter, but this proved too cumbersome and time-consuming. This problem instead requires only knowledge of the formula of the isogonal theorem, which however I find difficult to demonstrate non-trigonometrically.
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Calculators are not allowed
Is crying allowed?
Depends, if you do it silently then yes
Are those binomial coefficients?
Yes
Time to write some factorials I guess
Why do they sometimes use a dot and sometimes a cross?
Idk
Only one 101 gets factored out, rest is a mess
!show
Show your work, and if possible, explain where you are stuck.
do PIE
consider 404 balls, 101 coloured red, blue, yellow, green
how many ways to select 1 of each colour
(101C1)^4
but count it with PIE
What's that
principle of inclusion exclusion
I've heard that but what does it mean exactly
well consider the sets R = not selecting a red ball, B = not selecting a blue ball, etc
you can say that selecting one of each colour is the complement of their union
and then use PIE to calculate the size of their union
I don't get this
what's confusing you
I don't get what you're trying to say to do
you'll need to evaluate S through double counting argument
it's clear the number of ways to do this is 101^4
but you must now count it alternatively using PIE to get another expression for the same number
What this double counting?
counting twice
So counting the same thing in two different ways?
yes
@tardy bloom Has your question been resolved?
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I'm trying to show $Ha={x \in G | a \equiv x mod H}$
wai
$a \equiv b mod H \implies ab^{-1} \in H$
wai
$a \equiv b \mod{H} \implies ab^{-1} \in H$
Hanako
tidying up
wai
wai
sure it tells me $t= xa^{-1} \in H$
wai
@twilit field Has your question been resolved?
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$Ha={x \in G \mid a\equiv x\mod{H}}$: Let $x \in Ha$, there then exists $t \in H: x=ta$. We thus have $xa^{-1} =t \implies a^{-1}x \in H$.Therefore $Ha \subseteq {x \in G \mid a \equiv x \mod{H}}$.\ Let $t \in {x \in G \mid a \equiv x \mod{H}}.$ We then have $at^{-1} \in H$ so $ta \in H$. But $ta$ is the general form of an element of $Ha$. Thus ${x \in G \mid \equiv x \mod{H}} \subseteq Ha.$
Therefore $Ha={x \in G \mid a\equiv x \mod{H}}$
wai
Can I have this proof checked
@twilit field Has your question been resolved?
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Would you say that for the first question -2 2 and 4 are continuous from those sides or neither
And for number two is that correct
I’m pretty sure I don’t include 0 but not sure
Same for 1
I switched the -2 and 2
But how is it hard brackets if -3 wouldn’t be continuous
first off do not say "-3 is/is not continuous"
continuity is not a property of numbers but a property of functions
you're asking "how is the first interval closed on the left if the function is not continuous at -3?"
Ya
and the answer to that is: your function is continuous there. it is simply undefined to the left of -3.
so there is no left-hand limit to check and therefore no possible disagreement with function value or right-hand limit
your function is left-continuous at 0, that's why i included it in the interval (-1,0] which is just to the left of 0
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If I end up with LDNE on the inside
Like with problem 13
Does that make the whole thing LDNE
Or can I say the values in the other one where they don’t exist
Like could I say 13 is -4
what does LDNE mean?
Or just LDNE and I’m crazy
the g(x) limit does not exist so its good
Left doesnt exist?
Limit does not exist
f(g(x)) can exist even if g(x) doesnt
(in the limit)
examine both the RHS limit and LHS limit
so from RHS, f(x) goes to 1, that's right
so g(f(x)) goes to?
whats the limit of g(f(x)) as f(x) -> 1
this is the same thing as limit of g(u) as u -> u
And left is -2
okay sure, but we are doing only the limit from the right now
Ok
and then we do the left and check whether they are equal
Alr thanks bro
np
notice that even if g is crazy discontinuous, f(g(x)) can still exist in the limit
(the best example is constant f)
Can I do the same with 12
sure
in case you got different answer for left and right limit, then the limit wouldnt exist
np
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I’m back and I need more help
Whaat.
Substitute x = a
Ya but is that really it
Oh I was looking at 17.
Yes
So just get ca^2 -2a^2
What
k
Innit
3a^2
You need $\lim_{x \rightarrow a} f(x) = f(a)$.
Hardy
Yes
Ya we did that
All I can think to do is plot points
That's the one I was saying whaat to.
Fr bro
f(x) = 4 isn't even a property, unless they meant something like "for all x, f(x) = 4".
Which can’t because it’s also 3
I suppose that they could mean "there exists x such that f(x) = 4"
And 1
But it would be ridiculous to mean that and write what they did.
A kid in my grade sent this hw packet out to everyone
But like he’s dumb asf
He just went
And said impossible
Which is what I think I’m basically going to do
If each line with x in it is supposed to start with "there exists x such that" then it's doable.
Ya
Or alternatively, "for each of the following propeties, sketch a graph with that property"
But it's very much a case of guessing what the question is supposed to be because the question as written has no valid answer.
Yeah, that sort of thing would work for the "exists x" on each line.
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How would you long divide this
Okay that makes sense idk why i did that
Also you can do (x^4 - 1)+1 and split the integrals
I was thinking of that but when i searched it up i was told that long division is better
Can you please show me? I think i had a similar idea
Seems bs
Sure
Would be grateful
Okay thank you so much, i’ll try it!
Im new to uni math we didn’t have this in high school so im trying to get familiar with it
On that note can you please show me how to long divide it? Ik the basics i just forgot how now
@vivid terrace
Okay thank you so much its all clear now!
Okay so i did the process correctly, now i wanna write my answer, i take what i got on top and then what
Isnt that supposed to be the final answer
@vivid terrace Has your question been resolved?
You'd have to integrate it
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Okay
Wait
you opened another channel btw, the channel got automatically closed after a while
you can type .close, to close it if you want to
I didnt know how to open it 😭
you open a channel by simply sending a message in an available channel
do you still need this channel?
Yes just abit
ok.
I wanted to make sure of something
We expand it then we integrate normally right
In any other channel? Then it will open this specific one
if the channel is occupied then nothing happens of course
if the channel is available, you will occupy it until you're done
Is this how you integrate it
There should be a "dx" at the end of these lines but yes that's how you would do this one
Theyre asking to integrate x^4/x+1
x^4/(x+1)?
Yes
So i did long division
I got that part, but how do i move on forward from that step
Show your result
This
Oh ok, looks correct, but I'd like to make sure you understand what the result is exactly, can you write it out here?
From what i got its x^5/5 + c but i think its wrong how i did it
Oh that's why you did the thing in red
Ok that's not how it works
You divided x^4 by (x+1) and got (x^3-x^2+x-1), right?
Okay
What you showed by doing this division is that (x^3-x^2+x-1 + 1/(x+1) ) * (x+1) = x^4
So your integral becomes the integral of (x^3-x^2+x-1+1/(x+1)), not of [(x^3-x^2+x-1)(x+1) + 1]
Give me a second to comprehend
Im gonna write it down too
Why do we multiply at the end by (x+1)?
Where
Yes if there's no remainder
Okay okay, so bcus of the remainder we added it to our expression and multiplied it by (x+1)
No no the remainder R just adds R/(x+1) to your result
I should've written x^4/(x+1) = x^3-x^2+x-1 + 1/(x+1)
And so they asking for integration of x^4/(1+x) so we move it to the other side and integrate the left
Okay so yes its alone
x^3-x^2+x-1 is your direct result, 1/(x+1) is the additional term you can't get rid of because it comes from the remainder
So we integrate each alone
Well now you integrate x^3-x^2+x-1 + 1/(x+1) instead of x^4/(x+1)
Since it's a sum, you can integrate each term separately
Let me try and come back give me a second, ty for going through it with me
No worries no worries
No there is no (x+1) factor in the integral
Okay so where does it go
It's only x^3 - x^2 + x - 1 + 1/(x+1)
OMG YES THE OTHER SIDEE
ISTGG ughh
Okay okay i got you im so sorry
It makes things easier then
Kinda
Let me try for the 192810 time 
Is ok 
Yes that looks good
OMG IM SO HAPPY
i guess math is all about trying out till you get through right answer
Or ig its always like that for me
No that's math I'm pretty sure 
Ty @shell wigeon and @spare beacon so so much, its my first time encountering such an integral and both of you helped me a ton!
I finished my enquiry
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here, i was trying to simplify the LHS
the numerator should be just S
and intuitively, i was trying out with x1 = 1 and x2 = 2
summation of (S - x(i)) should be S?
but then the whole thing becomes 1
and then n/n-1 is, less than 1?
i dont think so, i made a mistake so, yeah
the numerator should be just S
wdym
Hmm do you know the formula for summing natural numbers from 1 to n?
Can you apply it to S?
im not getting it exactly
Isn't S the sum of the natural numbers from 1 to n?
but its the summation of x(i) and x(i) here are positive reals right
Ah mb
mhm yeah
I know how to prove it. First do you understand the problem?
Okay should I walk it through for you?
yes please
So we have S to be the sum of n positive real numbers, right? Let us just say that n = 3 for now and let S = a+b+c
Yep exactly!
Nesbitt’s inequality is the case for n=3. The inequality you have is more like a generalisation for any n
so i should follow the same procedure for this one as well?
Correct. Just try and see if it mathematically works out
i used AM GM for Nesbitts tho, going that way, that would be way too complicated tho, right?
Probably, idk the AM-GM route for this one though
Oh wait I might know it, but it shouldn’t be that bad though
It might get a bit complicated in writing it
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To solve integral like this is it considered formalized sufficiently (rigorous enough for calculus) not to the standard of analysis but for computational calculus
hi
Hi
I am still curious if I can use that cheat without having to prove it 🫣🫣
I mean it’s really powerful but I am unsure if it’s legit
which cheat did u use and where
wonder too
I uploaded a method I discovered on internet to connect a couple of identities
But those are minor details, is the solution overall okay? Like if a ta grades it they should count it fully correct right?
My method usually has domain mismatch
i see u seem to have a different method than WA
Yes it’s similar to the integration using Euler identities
So there are some domain issues but the result of integral isn’t unique the method works mostly fine (mostly)
domains dont really matter for indefinite integrals as long as it is defined at at least some domain so it is riemann integrable
if the method works then it is fine
Yes, so usually one doesn’t need to justify rigorous for why the method can work and as long as computation works out it should be fine? 🫣 for cal course
for finding an antiderivative, u just need to justify the steps u make like substitutions (usually domains as well if it is a definite integral)
i can imagine the prof also asking why it is integrable
The method is similar to this one but more practical so not that general I think “https://arxiv.org/pdf/2505.03754”
So the substitution is a bit different than usual
@undone heath Has your question been resolved?
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How to do the 2nd part of the question, sketching?
Graphing the results i mean
like on a numberline
or on x-y axis
xy axes I think
Graph the two lines and specify which area satisfies the inequality
How do we know the shape of the graph
theres only one line
x=10/3 is the line u want to draw
its just a vertical line
where x is 10/3 on each point on that line
then u shade the side where the x values are greater than 10/3
Then i shade the part on the right bcus it must be greater
yes but
for some specifications
they want u to draw specific types of lines
for strict and inclusive inequalities
usually one is a dashed line and one is a solid line, tho theres no set way for which is which
on the off chance that this is edexcel gcse maths, strict inequalities have a dashed line
otherwise look at ur spec
Its a direct entry exam for math for my uni
hm not sure then
Finished gcs already
I don't see how that's useful but I don't know what the question expects from you
Okay
Hopefully its just as we said
Seems easy enough
I'd be doing something like that:
some exam boards would penalise if the line is the wrong type (dashed/solid)
How do you come to this answer
I dont think the original 2 lines are necessary
since the shaded region has been solved algebraically
Then it's basically just stating an interval, no point in making it a graph
But who am I to question it
They say graph the results in the question
yeah pretty much, thats how I interpreted it
maybe the "results" are all the points shaded
not sure
Hmm
I interpret it more like "the results of your work"
if these things come with a mark scheme or a written specification, I'd fs give it a read
Linear inequalities in one variable: Inequality symbols and relations, the meaning of
solution to an inequality, Solution of linear inequalities in one variable and the use of
inequality notation and interval notation to express the solution, graphical presentation of
solution on a number line. Solution of simple word problems involving inequalities.
It doesn't say anything about the type of line u need to use so I wouldn't worry
as for whether u need to draw the original 2 lines, I'm still unsure
I suppose better safe than sorry
you'd draw the line like any other y=mx+c line, if its y>mx+c shade above the line, if its y<mx+c shade below
wait just draw the lines actually, they're not inequalities I just clocked
y = 1/3x + 2/3
y = 5/6x -1
from the original question
Each side of the inequality
yeah exactly
The question is giving you two lines and asking "when is the first below the second"
ur effectively shading where y=5/6x-1 "overtakes" the other
exactlyyy
You mean the left side snd the right side of the inequality given?
How do we make them into the points we use to draw the lines
as for interval notation, you'd put $ \left(\frac{10}{3},\infty\right) $
$$ \left(\frac{10}{3},\infty\right) $$
AnitaG
Okay
you just do "y="
to each side
Oh just that
and u get ur linear equation
Have you worked with functions yet?
Well if you have
- f(x) = 1/3 x + 2/3
- g(x) = 5/6 x - 1
These are two linear functions, their graphs are lines
The question is: for what x does f(x) < g(x)
Okay yes i got the point now
Here, f is the red line, g is the blue line
The picture helped me a lot to understand
Thank you both nel and anitag
It turned out to be easier than i thought
Also this saved me a ton
Hello.
I think im done here, ty to you both
Its better to use a free help channel if you have a question i’ll close this one
Oh ok.
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Why is this true?
Why does g being irreducible guarantee existence of m
if such an $m$ existed it would be a root of $x^{k-1} + x^{k-2} + \dots + x + 1$, which divides $g(x)$.
fucking hell is texit really still down
whatever
my point should come across just as clearly
this obv assumes m ≠ 1 but you're not picking 1 for this
because 1 = 1^k
oh i get it now
thanks
i didnt realize that x^{k-1} + x^{k-2} + \dots + x + 1 would divide g
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need help with 4)
oh, its not injective
take for example
f(1) = f(2) but 1 not equal 2
You sure?
?
What's f(1)?
n + 1 where n = 1
Ok, and f(2)?
n/2 where n = 2
1 + 1 = 2/2 ?
absolutely not
So f(1) =/= f(2)
im stupid
f(4)=f(1)
ye, my immediate thought
this is the counterexample as to why it isn't injective
what about surjectivity dude?
See if you can make all even numbers and all odd numbers with f(n)
dude I need help
what is the definition of surj
That for any element of the codomain, there is an element of the domain that maps to it
Let f : X -> Y be a function
Injectivity: f is said to be injective if ∀ x,y ∈ X . f(x) = f(y) ⟹ x = y
Surjectivity: f is said to be surjective if ∀ y ∈ Y . ∃ x ∈ X . y = f(x)
Bijectivity: f is said to be bijective if f is both injective and surjective
In other words, if you input the whole domain into f, the output is the whole codomain
ye
I said even number here but I didn't realize it worked for odds too
2p is always even, so f(2p) = 2p/2 = p
You're essentially mapping {2,4,6,8,...} into {1,2,3,4,...}
{2,4,6,8,...} is a subset of the domain
{1,2,3,4,...} is the codomain
You're covering the entire codomain, so f is surjective
p can be odd
Yes but not 2p
wdym
... I mean 2p is even
Not sure what's confusing you
The input is n = 2p
Since n is even, f gives you n/2 = 2p/2 = p, as output
That works for any p in N
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let x be a natural number,
then f(2x) = 2x/x = x, and thus, we can get to any natural number in this manner
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<@&268886789983436800>
what is this
scam
is this propaganda
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oh right
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I don't get the steps under that black line
So I found the x intercepts when y is 0
What do the 3 dots mean?
it's a shorthand for therefore
I see
Much more rare, is three dots in an upside down triangle, which means because.
Bonsoir j'ai besoin d'un mentor qui pourra m'aider en maths en privé
but you'll see therefore reasonably often.
!occupied
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Kk
So how is y=-12 when x was 0 too
Just to structure things, up to and including the therefore they find the intercepts. Then after that the way I see it they restart from y = 2x^2+5x-12 and complete the square to get the turning point.
well for this you can plug x=0 into 2x^2+5x-12
and see it's -12
2x0^2+5x0-12=0+0-12=-12
Oh yeah got it
But what I'm not getting what they did do after I drew the black line
So we have 3 coordinates
Or intercepts?
those are the 3 special point on the graph of y=2x^2+5x-12. At x=-4 and x=3/2, y=0
they deduced this from the factored form (2x-3)(x+4)
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yeah it was kinda explained in the margin you just had to separate the arguments into chunks :kek:
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Hii!! can I get help with this problem? I’ve been stuck on it for 30 minutes now 💔
how're you feeling about LCMs now? 
feeling kinda pretty confident about it, but at the same time. I’m trying to understand more yk?
sure! do you want me to repeat what I said earlier about them?
yes
recall that the multiples of a number are all the numbers you get by repeatedly adding that number to itself. for instance, if the number is 5, then the multiples are 5, 10, 15, 20, 25, and so on
now if we have two numbers, a "common multiple" is any number that is a multiple of both numbers
here's an example:
the multiples of the number 2 are 2, 4, 6, 8, 10, 12 etc
the multiples of the number 3 are 3, 6, 9, 12, 15, 18, etc
the common multiples are the numbers that appear in both of these lists... which would be 6, 12, 18, etc in this case
the least common multiple is then the smallest common multiple between the two numbers. in our example, that would be 6
does this make sense?
we're going to need this to find a common denominator in just a moment
but I want to make sure that this concept is clear first
WAIT
I REMEMBER NOW LMAOAOAO
that is such a brain refresher
im basically looking for the common between the numbers that has the same number then crossing them out ?
yeah! to find the LCM, you can first find all the common multiples, and then cross out all of them but the smallest
HAAAAA I GET IT
if this is clear on you, then we can move onto the fractions 
so earlier, I mentioned that we can rewrite the number 4 as 4/1 to make our lives more convenient
oh, uh
?
the bot is down
okay, I'll avoid using the bot then
do you remember this? 
4/1
yeah!
once we do that, the expression back in your problem is - 4/1 + (- 3/7), agreed?
agreed b
now, to add these fractions, we first need to find a common denominator
and that common denominator is going to be the LCM between the two denominators
let's do this step by step, just so we're clear on how to do this
first off: what are the two denominators in question?
denominators as in the bottom numbers right ?
(remember that if you have a fraction, the denominator is the number in the bottom)
yup!
I'm more or less asking you: what're the two bottom numbers in the expression - 4/1 + (- 3/7)? 
oh. I was adding the fractions all together, I thought that’s what you meant.
3/7?
nono, we're taking this slow and steady
one step at a time
this is how we're going to add the fractions
OHHH
that's a single number, and not the denominators 
wait now im confusing myself, am I finding what’s half
WAIT
OMG
let me draw, since @grand pond is down
@lilac niche we've got two fractions here; what are the two denominators/bottom numbers?
1 & 7?
there isn’t none ?
? 
can you list out the multiples of 1?
OH
those are the numbers you get by adding 1 to itself over and over again
1,2,3,4,5,6,7
7 14 21 28 35
great!
I forgot the rest idk
which number makes an appearance in both lists? 
1!
that's okay! we won't need it 
does 1 appear in the list
7 14 21 28 35? 
the two lists are 1, 2, 3, 4, 5, 6, 7 and 7, 14, 21, 28, 35
which number is in both of them?
there you go 
you got it!
so 7 is the LCM between 1 and 7, which shouldn't be too much of a surprise
with this in hand, we're ready to start rewriting our fractions
YAYAYAYAYAYAY
remember how we rewrote -4 as - 4/1 earlier, for convenience?
yes
well, we're going to do that again
we'd like to write - 4/1 as - (something)/7
let me draw it out
7?
it won't be 7, but let me first ask: do you know why we want to do this?
cause it might seem like a strange thing to want to rewrite this number again, right?
yes
but the reason is that we can only add fractions together when they have the same denominator
back here, we can see that the denominator of -3/7 is 7
so it's in our best interest to rewrite -4/1 to have a denominator of 7
because once we do that, we can simply add the numerators and call it a day 
this is the pivotal reason why we wanted to find and LCM to begin with
OH
okay I understand, what do we do next ?
the ones I said?
the LCM is going to be the number we change our denominators to
in this case, the LCM of 1 and 7 is 7, so we want both of our fractions to have denominators of 7
but -3/7 already has a denominator of 7, so we don't have to do any work there
it's only -4/1 that needs to change
are you following so far?
go ahead
both top numbers are changing because they are negatives?
no, the top number will only change as we need it to in order to change our fraction to have a bottom number of 7
that's what the ??? is here
we must find what the top number is going to change to
and then we are figuring out what the top number is being right?
the reason it changes at all is that we need to preserve equality: if we kept the top number as 4, then the equality would read -4/1 = -4/7
but that's clearly not an equation that holds 
yes! we can get into that now, if you're ready
we're going to use a little trick from multiplication of fractions to do it
im ready :>
do you remember how to multiply fractions? 
if I showed you this, could you tell me what it's equal to?
mm, that sounds a bit wrong 
that's for when you have an equation to begin with and you want to simplify it, not really for multiplying fractions 
but I'll tell you straight up: it's literally just "multiply the top numbers and multiply the bottom numbers"
Oh.
6/12?
exactly!
now, we're going to make use of this fact, as well as the fact that any number times 1 = itself
following so far?
if so, we can get right into it
?
that’s not the answer?
we're still in the process of doing this!
we're not done the problem yet 
I'm taking this super duper slow, to illustrate the points clearly
are you ready to find ??? now?
yes 
they're genuinely confusing at the start, to be fair
addition and subtraction of fractions in particular is smth students commonly find very confusing and difficult
you're doing great though, I promise 
we're nearly done!!
I’m more of an multi & finding the slope person 
okay okay
first things first, we're going to use the fact that any number times 1 = itself to get this
makes sense?
- 4/1 = - 4/1 x 1?
yup!
we're conjuring up the 1 out of thin air
we're allowed to, because anything x 1 = itself
ohh
now, we use another special property of 1: any number divided by itself is equal to 1, so we can change 1 to 7/7
OH OKAY I SEE
nono, ignore 6/12
that was an unrelated thing that I wanted to use just to illustrate an idea
it has nothing to do with this problem
28/7
amazing!
YAYYYYY
look at what we have now
we've successfully changed -4/1 to -28/7
so 28 = ???
we've done it!
the original number in your problem was -4, not 4 :p
oh
so we had to carry a negative sign everywhere
but with that out of the way, we can finally return to the original problem
i am beginning to get whelmed 
OHHH
remember why we're doing this: we want to change -4/1 to have a denominator of 7 so that we can add our fractions together
so I enter the answer like 28 on top and 7 on the bottom?
this was the one and only reason we did all of this work to begin with
yes!!
what abt the negative..
the negative just sticks around
instead of 28/7, it's - 28/7
there's nothing to worry about
the negative can go on the top number, bottom number, or in front of the whole fraction
it makes no difference
anyhow, all of that hard work we did was just to get to this point :p
since we found that - 4/1 = - 28/7, we at last have this equality 
ohh
and now we can just add the top numbers together
like that?
didja get it right? 
sorry, I had to answer my door 
I'm back now
okay, to add fractions with equal denominators, you just need to add their top numbers and combine their bottom numbers
do you want me to give an unrelated example, for illustrative purposes?
I used desmos for it
ehh, you should learn how to do it yourself too 
see this
ah? I'm not sure I follow 
bc that’s what I used back in high school all the time.
fair enough, but I know you're smart and capable enough to do this on your own 
you don't need Desmos for this
I think you misunderstood what I explain, I did it on paper. I used desmos to see if I did it correctly.
congratulations 
you did it!! 
I hope I was able to clarify a few things along the way 
you did you did !
if you practice these sorts of questions enough, you should be able to do them within a time frame like 10 seconds :p
nah, I only guided you along :p
you filled in all of the details
you have two options:
choose any of two of them first, add them together, and reduce it to the case of only 2 fractions; or
get an LCM between all three of them, adjust the numerators all at once, and then add
can you first simplify everything in the brackets? :o
EVERYTHING ?
well... not quite, because fractions are already in fully simplified form
ADD???
I'm more referring to the 4 - 2 and 5 + 3 expressions in your brackets
like, just do the addition/subtraction :p
I despise math deeply.
hey, we're gonna get through this together 🤍
take some deep breaths, calm your nerves, and let's face this together 
if you're not feeling it rn, we can also stop
that’s how I feel rn
would you like to stop for now?
I don't want to force you to continue if you're feeling bad about this
prioritize yourself first 
it’s honestly kinda hard, especially when it fractions I forgot to do by hand 
Do u guys know how i can get help like a channel like this for something i really need help in (sorry for being here js asking)
hey there! welcome to the mathcord! 
so this is a help channel, but it's currently being occupied by cosmos
you should open your own, like #help-11, to get help 
mmmmmmmmm ok ty
rule of thumb: if there's a name attached to the channel, it's occupied
if not, then you're free to ask in it
funny you ask, because I was about to apologize for having to take my own leave soon 

omg can I call u the wizard tutor. ur like an magical wizard 🙂↕️
I'm off to have dinner in just a few minutes, so this is good timing
get some water, take a break, and enjoy your evening!! 
I'm off now!
ohh okay ! BYE WIZARD TUTOR!
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help plss
guys i only have 10 more minutes
im sure F is false and D is false
and C is false
@lavish venture MY GOAT
@chrome swift Has your question been resolved?
do you still want help with this
@chrome swift pls close the channel if ur done lol
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need help with vi)
in vi)
ok so
we have to check is f is injective or surjective right
or both
so
a>0: f(a) =2a
this is injective on Z+,ie positive integers
this is because 2a gives even numbers which are distinct for distinct a
now a<=0: f(a)=1-2a
this is injective on Z<=0
ie non positive integers
because it always gives +ve odd numbers which are distinct for distinct a
might wanna guide OP through instead
@tidal turret Has your question been resolved?
@scenic wyvern can you close channel, OP is ignoring or is disconnected
i'm not supposed to do that unless OP says so (or is trolling)
ok then
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O(a)=3
O(b)=4
Then o(ab)?
not possible to determine
Why?
depending on the group it could have different values
Group is abelian
that would be important
So??
so you should've mentioned it in your question rather than making people help you solve a seemingly under specified problem


