#help-17
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how is expansion of binomials related to combination?
if you look at the binomial (a+b)^n
when you're expanding it, you're basically picking between a or b, n times
if you pick a, k times, you have b n-k times, so you're on the a^kb^{n-k} term
what do you mean by picking
but there are n choose k ways to pick k as from the n total brackets
(a+b)^n = (a+b)(a+b)...(a+b)
ye
you can multiply this out by picking either a or b from each bracket
Choosing, selecting, taking
i dont understand
if you pick a every time, you get a * a * a * ... * a = a^n
why are picking it out
yes
the a*a term is the same as picking a from both brackets
we have to multiply every term in every bracket by the terms in every other bracket
where do we get a*a + a*b + b*a + b*b from
from a(a+b)+b(a+b)
ye
you multiply the first terms of each (same as "picking" the first term of each bracket, then multiplying them), then multiply the first term of the first bracket and last term of the second bracket, etc.
each multiplication requires picking a term from each bracket
in the longer set of brackets, (a+b)(a+b)(a+b)...(a+b), it's the same thing
you need to multiply a term from each bracket, which is the same as picking a or b for each bracket
ok
so a term in the full expansion comes from a choice of a or b from each bracket
if you pick k a's, there must be n-k b brackets remaining
so you have an a^kb^{n-k} term
but there are n choose k ways to pick the k a's from the n brackets
ok this is confusing
so this term has an additional coefficient of nCk
im confused on this part
what is the a term?
the a^2 term?
ok
ok
a term in the expansion of this comes from picking some x or y
like, with (x+y)(x+y), we can pick x from both
to get x^2
or x from first, y from second to get xy
etc.
so each term, like x^2, xy, y^2, comes from these choices
in the general case (x+y)(x+y)...(x+y) with n brackets
we can pick x from k of these brackets to get x^k
but if we didn't pick x, that means we picked y for that bracket
i think u mean a term in the expansion of this comes from picking some an x with some other x or y
why is it x or y
I mean x or y from each bracket
and it x and some other term
it'll come from one choice of x or y from each of the n brackets
we can look at the cubic case: (x+y)(x+y)(x+y)
if we pick x from all 3, we get x^3
if we pick x from the first, y from the second and third, we get xy^2
right?
so with n brackets, (x+y)(x+y)(x+y)...(x+y)
if we pick k x's from among the n brackets
that means there are n-k brackets left over from which we pick y
so we have a x^k y^(n-k) term
i cant understand the k x's part
what does k x's mean
we pick x from k of the brackets
where k is just some number less than n
in the cubic case, we had k = 3, which is picking x from all 3
and k = 1, which is picking x from 1 of the brackets
it just means how many x's you have
so n=k
no
since n is also the number of brackets
in the cubic case, we could pick x from the first, and y from the last two
to get xy^2
this is an example of k=1
ok
if we pick x from exactly k brackets
there are n-k brackets remaining from which we pick y
in the cubic case of n=3 and k=1, we had xy^2; note that 2 = 3-1
ok
in this example
we have n=3 (because we have 3 brackets)
and k=1, because we picked 1 x
k can be 1, 2 or 3
if we don't pick x from a bracket, we have to pick y from that bracket
because we need something from each bracket
no
even when we had k = 1
we picked x from one of the brackets
that means we need y from the other 2
yes
but I'm saying you must have y in there even if k is not 0
we had y in there when k = 1
the only time you don't have any y is when you pick x from every bracket, so k=n
ok
the number of x and y must add up to the number of brackets
because you need exactly one x or y from each bracket
so if you have n brackets, and you pick x, k times
you have n-k brackets where you must pick y
because k + (n-k) = n [read this as number of x + number of y = number of brackets]
is this okay?
ye
gives a $x^ky^{n-k}$ term
Desync
yes
but, there's more than 1 way to pick x k times from n brackets
there are exactly n choose k ways
wait, I'm assuming you know the choose function
since you asked about combinatorics
is this correct?
alright cool
theres 1 than 1 way to pick x k times from n brackets
ok
and say we have k=1
so we want 1 x
well, we could pick the x from the first bracket
or from the second
or from the third
there are 3 choose 1 ways to pick that single x from the 3 brackets
so more generally, there are n choose k ways to pick k x's from the n brackets
because we're choosing k brackets to pick x from out of n total brackets
ye
that's exactly the binomial coefficients
ye but why
why does it represent the coefficient of the terms
if its telling us the number of ways to pick x from the brackets
okay, so in the cubic case
we can pick x from the first bracket to get x * y * y = xy^2
or
or we could pick x from the second to get y * x * y = yxy = xy^2
yyx
yes
3 choose 1
so that 3 is the coefficient
and it matches up with the number of ways to pick one x from three brackets
yes
so the number of ways of picking
gives the coefficient on xy^2 when you sum them upp
ok
because if you have 3 ways of picking, you have 3 copies of xy^2
the "ways of picking"
is given by 3 choose 1
because the choose function is defined to give the number of ways to pick
so if we have (3 choose 1) ways of picking
we have (3 choose 1) copies of xy^2
ye
so the coefficient is (3 choose 1)
pascal's triangle is just a way of writing out (n choose k) for various values of n and k in a systematic way
how does a triangle made from adding the numbers above it gives us the coefficient of binomial expansions
why not give us the coefficient of trinomial expansion
oh u know
is there a trinomial theorem?
there is
there's a general multinomial theorem
It's a property of the binomial coefficient (which in turn arises from the factorials)
I guess it'd be more of a tetrahedron
oh ok
I don't know how to draw one, and I don't think they're really used in practice
because we have a formula for the coefficients
maybe it can tell us some number sequence
you can go explore that if you wish
ok
jk
thanks for rthe help btw
i really appreciate your help
and it really makes me understandthe topic better
np
combinatorics is fun, but a lot of the proofs are really condensed and hard to get into
you too, take care
remember to .close the channel if you don't have any more questions
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it's .reopen
oh ok
.reopen
✅
did you have a follow up?
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Here given rank of matric is 2
So i tried to 3×3 and determinant 0
How to find T it then
Is the determinante only 0 for t=0?
find the det in terms of t
Wait are those two different matrizes?
You should use the word submatrix here to fit the context. Saying "matrix" for a submatrix will confuse everyone
anyway, this is not 0 for just t=0, and note that this is not the only submatrix of dimension 3 either
yes, t=3 should be the only values that makes every submatrix of dimension 3 have a determinant of 0
well I don't see any other way than doing row operations. You could find the determinant of E if you are eager to do it by hand
There is probably a way of making two of any columns/rows be dependent, but then that would involve solving a system, so that's not really any better
anyway, start out by choosing a pivoting column
Multiplying first row with-1 and adding gives many zeroes
I don't know if it's a good idea
well the first thing to notice here is that when t=0, we will have all of the rows/columns be independent, meaning the rank of this matrix is 4 in this case. So, now we want to check for when t!=0. What this means is that you can now multiply/divide a row by t without worrying if it'll change the result
so now, can you find operations that makes all of the elements in the first column (except for the first one) to be 0?
ok, I need some confirmation first, are we doing row operations or column operations?
I was doing row operations but when you are suggesting column operations
oh oops, I meant this to be a pivoting row, excuse me there
technically doing column or row operations is fine, I just need us to agree on one
Let's go with row
alright then
anyway, let's continue with the case when t!=0.
As you can see, a row operation R3-R4->R4 will make the first and second element on row 4 to be 0. Continue this with row 2 and 3 makes the first element on row 3 be 0. Now how can we make the first element on row 2 be 0?
If we multiply first row 2 with a t then subtraction with first row
alright looks good
now before moving on, let's see what happens when t=1
what would be the rank of E when t=1?
Rank will be <=3
yes, but further note that when t=1, the bottom three rows will be all 0, what this means is that there is only one vector that spans this matrix
meaning the rank of E is 1 when t=1
so now we need to consider the case where t!=0,1
Yes rank will be 1
you can see what the pattern should be, just keep working down the rows and consider the cases until you have reached the final row
shouldn't be too bad since our matrix is very nice
Can you elaborate more about cases?
What do you want me to do with rows?
If I put t=0
Then rank is 0
Null matrix
again no, like I have said, when t=0, all of the row vectors are independent
this is trivial when you write it out, so in this case the rank is 4. Meaning you don't care about the value t=0 anymore
what this essential does is it allows you to multiply by the scalar t. You usually can't do this when t=0, because then that operation wouldn't make sense
so a similar thing happens for t=1, what this just does is to make sure that t=1 is not a value that we care about, so we can multiply by the scalar (t-1) or (1-t)
our goal is still trying to row reduce the matrix
(note that you only need to do one more row operation and you are good to go)
Now idea
Because each operation is disappearing leading zeroes
And this is taking so much time for me to solve just 5 minute thing
.close
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Can someone teach me the steps for this?
@unborn locust
Yes
How do you find the area of a square base 2 and height 3
2x3
2y+3
remember multiplication doesn’t matter the order
2x3 equals 3x2 so it doesn’t matter what you choose as the bad
now what’s our heigh
t
if you chose 2y+3 as base
y-1
So we just multiply them
Yeah
Do you know to multiply (2y+3)(y-1)
Wdym?
Like how to expand those brackets
What did you get
2y^2 - 2y + 3y-3
Collecting like terms what are we left with ?
Could you expand on that?
Collecting like terms is like
x+3x+3 simplifies to 4x+3
The terms ahve the same pronumeral which is x
so we just add them
Oh so like 2y2 - 2y + 3y
That simplifies to what
2y^2 - 5y = 3y
How’d you get that
go back here
and just simplify like you normally do
i think i confused you
2y^2 - 5y - 3?
Ohhh right nvm
Do you underdtand the problem?
1y is equal to y
Yeah
How would I put that in the equation?
Oh right
It’s simply 2y^2+y-3
Oh ok
as the expression for the area
Ohh
hope this jelped
Nope
Is that the final answer?
ur done
You can also solve similar problems
for example if you are asked that for a ttiangle
right angled
we know the area formula for a triangle
so we do the same thing
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https://youtu.be/Ip3X9LOh2dk?t=504
I don't understand what he meant by this -- "If both b and c are non-zero then that b*c term tells you how much this parallelogram is stretched or squished in the diagonal direction."
The determinant measures how much volumes change during a transformation.
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it is more of a rough intuition than an exact description, but as the terms b and c grow very large compared to a and d the parallelogram will sort of tend to be longer and thinner
if you consider how the matrix translates the vectors (0,1) and (1,0) which will end up being the sides of the parallelogram that is perhaps a way to visualise it
hmm also ig the orientation of the area bc is opposite (to the area ad) so it's subtracted from b*d ?
yeah that’s a good way to describe it
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Hey, I'm trying to understand a proof which I found online and I'm stuck at an apperently fact, namely that the red and the yellow angles are the same. Unfortunately the proof doesn't discuss it further and I can't figure out why the two angles of the same color are the same
@remote vector Has your question been resolved?
@remote vector Has your question been resolved?
cyclic quadrilaterals my frend
BCQP is cyclic
so opposite angles are supplementary
cyclic means it can be inscribed in a cicrcle
and the diagram shows it being inscribed in a circle
@remote vector
so BPQ + BCQ = 180 so BPQ = 180 - BCQ = BCA
so BPQ = BCA
the yellow angles are equal
same for the red
does this answer your question?
In Euclidean geometry, a cyclic quadrilateral or inscribed quadrilateral is a quadrilateral whose vertices all lie on a single circle. This circle is called the circumcircle or circumscribed circle, and the vertices are said to be concyclic. The center of the circle and its radius are called the circumcenter and the circumradius respectively. Ot...
@remote vector Has your question been resolved?
Yes, thanks a lot!
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Tried integrating a semi circle got this weird thign
the divison shouldn't be there right?
why are there degrees 
$$ u = x \frac{90}{r}$$
$$ du = \frac{90}{r} dx$$
$$ dx = \frac{r}{90}du$$
$$\frac{2\pi r^2}{90} \int_0^r cos(u) du$$
I did $$\frac{90}{r}$$ because that's how you umm
you
find the radius of a cross section
with cos()
i think
cos(90) = 0 which would be the very end of the semi circle
Is your cosine in degrees??
If so sine is NOT an antiderivative
By the chain rule, the derivative of sine (in degrees) would be pi/180 cos (in degrees)
wut?
The whole reason to use radians is that the derivative of cosine is -sine and the derivative of sine is cosine
If you scale the input differently, you need to use the chain rule to calculate what the result should be
It works the same as any other type of scaling a function
👍
No problem
It can be trippy
.close
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hello could i get help with this question? the proposition hint is included
used lim laws to get to here but now i am stumped 💀
Ok, so this is a misguided idea
You can’t use limit laws in the original just yet because your denominator will approach 0
ohh
The limits won’t exist if you split it like this
my original idea was to say that since f(x) is a polynomial u could simplify the expression in the numerator and then factorize
and pray to god that one of the factors are x-3
What should the nominator approach so that the overall limit may exist given the denominator approaches 0?
The key is to use the proposition hint
both the top and bottom has to be 0 for the limit to exist?
sometimes
Yeah, so f(x) - x - 4 should approach 0 as x -> 3
CST
You should be able to answer the question by now
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wow
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how would i do this?
Well intuitively i made the inscribed squares vertexes touch the midpoints of the bigger square
but idk how i could justify that
Have you learned calculus
sure but i have like 1 minute for the problem
surely i can't be lost in the weeds of optimization
That’s different to having to justify it
You just need to find the area
This is obvious yes?
@urban obsidian Has your question been resolved?
yes
Use Pythagoras
If it’s multi choice
You just need to find the answer asap
Justification is not needed
But if you did want to justify I would probably use calculus
oh no
i know how to find the area
of the inscribed square
i mean how do i know
which one minimizes the area?
like what orientation
i did this too and found the area
it was correct but it was just a hunch tbh
You just need a hunch
For MCQ
If you want to justify it you probably need calculus
by hunch you mean
i assumed the orientation was 90 degree
well "sleeping rectangle"
whatever you call it
exactly what you drew tbh
Like this right?
is there anything i can "memorize" though?
Yeah
yeah
i can do calc yeah but is there any facts i can memroize
I mean that’s the obvious hunch
about maximizing shit
it also is the easiest one ig lol
I guess you can try to visualise it
They won’t make it too hard in mcq
That’s not the point of mcq
MCQ pretty much (in my experience) are always the ones where they mostly have tricks you can use
Like there’s a fast and short way
And if you do the short way it gives you more time for other questions
you're right
i just saw some people were spreading "concepts" relevant to this
something like this
ofc i guess i could prove via calculus
or could i
i might be rusty actually so maybe not
but where does this originate from
Well all this can be proven via calculus
As I’m dumb I would do it with calculus
But maybe there’s another way geometrically
I’m too dumb to see one if they exist
welp guess i'll do that as well then
Mainly because I know I can do it with calculus and I won’t run into problems
onc ei prove it once ig it gets easier to remember
i could probably but not sure tbh, i'll try and see
was looking more for geometric proof ig
Although I do remember that the biggest volume for surface area is a sphere
And likewise perimeter and area for circle
Because bubbles are spherical
It’s got the least potential energy or something
Something physics something idk
hmmmmm
welp lemme try
thanks for the lead
i guess you're right
in that the orientation that you chose
There’s also one about hexagons
it's probably the easiest to do in terms of finding the area
They tile the plane with the least perimeter
ooo never heard of that tbh
Something about honeycombs I think
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But this is really just random reading and stuff so I don’t expect schools to expect this to be just a known fact unless you specifically covered this
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Don’t know what to do
,rccw
I'm not sure but does knowing 2sin(Φ)cos(Φ) = sin(2Φ) help..?
Hi
Use this formula
Products to sum
Nvm I read the q wrong
👍
i will try doing it now'
i got it it is D
thanks mate

Yup 👍
thanks
@craggy imp Has your question been resolved?
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and then autor writes this :
so my issue here is that in the first formula x goes to 0 from negative direction as well
and therefore I can not understand how we get second equation from the first one
do x = -1/n
well you wanted x from 0^-
so x=-1/n will work for that direction
what does n approach?
writing n -> +- inf doesn't quite make sense
1st limit converges to e => 1st limit from positive direction converges to e => 2nd limit converges to e
Shouldn't this be sufficient actually?
you already have 2?
why
I think they just didnt understand how was the second formula derived from the first one
oh
these two are not the same
is that right? you don't understand how to get eqn 9?
right. so what's your question
i want to get secod eq from the first
The fact that first limit converges from both negative and positive direction is more than sufficient to conclude that the second limit converges
To make that conclusion, you need just the positive direction
aa that is good explanation
i understand now
tnx
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hayley!
@dim silo Has your question been resolved?
what should i have put?
$2\log y$ is equal to $\log(y^2)$
hayley!
oh ok
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,rccw
your handwriting looks neat
this does, but why did you switch the function of the 3rd part to 3x/2 + 2a
Thanks 🙂
I don't think I switched it?
for the function to be continuous on all real x, it should also be continuous on those points where it is changing its definition.
Dyssrupt
yeah
but then how do u solve for a and b? do you set it equal to 4 as mentioned in the 3rd piece
what is the definition of function at x = -1?
ax-b if x <_ -1
and for x>-1?
so now just do this
but a and b are not defined
just substitute the value of x
@knotty snow Has your question been resolved?
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$$\Gamma(\pi) = \int_{0}^{\infty} t^{\pi - 1} e^{-t}dt$$ $$Let u = e^{-t}$$ $$\implies du = -e^{-t}dt$$ $$ln(u) = ln(e^{-t}) = -t$$ $$\implies t^{\pi - 1} = [-ln(u)]^{\pi - 1}$$ $$\Gamma(\pi) = -\int_{0}^{\infty} [-ln(u)]^{\pi - 1}du$$
just a sec
0 and infinity are limits correct? and not 0^infi
yes
Climate
What should I do now ? Any substitution?
if I remember the formula correctly
lets assume
f(t) = t^PI
g(t) = e^(-t)
Integration by parts rule:
First as it is, Integration of Second, minus Integration of (Integration of second times derivative of first)
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Find all continuous equations $f : \mathbb{R} \to \mathbb{R}$ such as:
$f(\sqrt{2}x)=2f(x)$ and
$f(x+1)=f(x)+2x+1$
For all $x \in \mathbb{R}$
BeeReallyYum
I figured that f(x)=x^2 is a solution
but it was just a guess and I couldn't prove it
I got 4f(x)=f(2x)
this will be helpful
prove that this has to be true for integers first
right I think I can prove it easily with induction
but I don't think that's enough
because that's only one solution there could be more
but yeah i'm kinda stuck there
prove that f(n) = n^2, you're almost there
Since f(0) = 0 because of the first equation, the second equation gives you a unique solution f: Z -> R, then use 4f(x) = f(2x) to extend uniquely to the rationals of the form k/2^n and then use continuity
and would that be enough?
like that doesn't really account for the other possible solutions
So there is at most one solution
wait i'm sorry could you explain how that works
ok so are you aware of the diadic numbers?
it's the base 2 version of decimal numbers basically
so a number's binary representation?
nono
Decimal numbers can be written as (integer).abcd or integer + a/10 + b/100 + ... AS LONG AS the sum is finite
diadic numbers are basically the equivalent with powers of 2 :
it can be written as integer + a/2 + b/4 + c/8 + ... with a finite sum
Or even better, as k/(2^n) as explained above
oh alright got it
Actually those are not 2-adic numbers but rather dyadic rationals
that makes sense
2-adic numbers are a different, more complicated thing
sorry got confused with their french name
we get confused between diadic and diadic very easily
anyways
first prove this is true for integers
yeah so how does that help in this problem
then prove it is true for all diadic numbers
then, use that the set of diadic numbers is dense in R
alright yeah got it
but I guess I can't prove that it's true for all diadic numbers using induction right?
you can, because all diadic numbers can be written as k/2^n
so your induction will be on n
this is the analysis synthesis reasoning we're doing
you're showing that f solution => f(x) = x^2
so there is at most one solution which is the square function
reciprocately, you can show that this possible solution works
and so x^2 is the only solution
i'm sorry i'm kinda confused
how can we prove there is only one solution by showing it works
that's not what we're doing
we're showing "if f is a solution, then it HAS to be this one"
Let S be your set of solution functions. You want to show S = {x-> x^2}
so you show $S\subseteq {x\longmapsto x^2}$
rafilou2003
because you know the other inclusion is true, so you only have to prove this one
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What do we have to do to the conversion factor if we are dealing with units that measure area?
the factor tends to be (the conversion factor between the units)^2, so say you have 1m^2, thats 10000cm^2 since 1m=100cm
1m=100cm, so 1m*1m=100cm*100cm => 1m^2=10,000cm^2
@glacial meadow Has your question been resolved?
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I'm really stumped with this
does $\theta^2 \tan \theta$ do anything naughty at $\theta = \pi/6$?
Bungo
any discontinuity, does it blow up to infinity, etc
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Why is this definite integral not equal to 1 - pi/2 ? I can't come up with the solution wolfram alpha suggests
show work?
,w integrate x^2/(1+x^2)
Lmao yeah thought so, arcsin is the root a^2-x^2
means?
You used the wrong inverse trig identit
Derivative of arcsinx is not that
It’s arctan which you’re meant to use
.close
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how do you solve part a and b
something to do with Normal forces and stuff
i get that the weight of the person is 50*9.8
meaning force down
but the other force which is the normal is not equal to WEIGHT on the person cuz the lift is going down?
not sure where to go from there
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@dusk jackal
I recommend you to watch this video that will help you understand how to solve this kind of questions
https://youtu.be/sVVKpRvuNG0
This physics video tutorial explains how to find the normal force on a scale in a typical elevator problem. It discusses how to calculate the apparent weight of a person when the elevator is at rest, moving upward with constant speed, downward with constant velocity, accelerating upward or downward. It uses free body diagrams and net force cal...
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(\phi:\bR[X,Y]\to \bR[t]:X\mapsto t^2,Y\mapsto t^3)
prove that Kernel of (\phi) is ((X^3-Y^2))
!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'm told it's wrong
4. I got an answer and would like my work checked
5. I have a question about someone else's worked solution
6. None of the above
I how do I show there isn't any other polynomial without X^3-Y^2 as a factor in the kernel
You want to show Ker(phi) = (X^3-Y^2)
so it's a double inclusion principle
you show Ker(phi) subset of (X^3-Y^2)
yea that idk how to do
the obvious hint here is a bit revealing so i'll try and be annoyingly vague: you're trying to show that something in the kernel, f, is divisible by (x^3-y^2), assume it's not, then how can you write f? (not actually a proof by contradiction)
I had a much more difficult proof so I'll delete
i dont really see it
We're dealing with polynomials, so we have division
do I quotient R[X,Y] by that ideal, then look at all the other elements except the 0 element
another annoying vague hint: 7 = 3*2 + 1
alr so div algorithm
yeah
I've not seen it for 2 variable polynomials
how should the degree of r[X,Y] look like?
it wont matter
well it will if you want to apply division
actually its a good point whether it does general to multivariate polynomials i dont know off the top of my head
the degree would be deg(X^nY^m) = n+m
since R is a pid then probably does
i was just mirroring what you do in the single variable case but here you might need grobner basis shite

nah bruh just deal with it as if deg(X^n Y^m) = n+m
sure i think its fine, you deffo can write f = g*(x^3-y^2) + r(x,y)
the degree of r wont matter as you'll soon see
no im still unsure this guarantees r is a polynomial and not a rational function
alr so
p=q(X^3-Y^2)+r
where r has degree <3?
how would X^5= X^2(X^3-Y^2 )+X^2Y^2
deg of r is 4
if r is of degree < 3, then r = aX^2 + bXY + cY^2 + ...
wot, yea but what went wrong in my example
if this is fine, then you just apply the map, you dont need to worry about the degree of r beforehand
is there some concrete reason why phi(r(x,y))!=0
You can just show that
$\mathbb{R}[X,Y]/(X^{3}-Y^{2}) \to \mathbb{R}[t]$ is injective actually
Cogwheels of the mind
Because if (X^3-Y^2) is strictly contained in the kernel, this homomorphism isn’t injective
x=X+(X^3-Y^2), y=Y+(X^3-Y^2). The image of f(x)+g(x)y, which is f(t^2)+g(t^2)t^3, being zero must imply that f(x)=g(x)=0 otherwise there is some even degree polynomial =odd degree polynomial
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tyty, this was a really kool way
Np
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pls help
function question btw
determine if the relation is a function
then find the domain and range
i did the first one
y= 2x^2 -3
?
yep
ok
question is to determine if the equation is a function or not
now i need to find the range
ok
do you know where the minimum value is?
yeah
yes
OHHH
I SEE
so
[-3, inf)
yes
with this one yes
with c it might be more helpful to isolate x
oh why could u explain
because you have y^2, when you square root you will get +-
so it might be easier to get x = ....
so we divide to get the first variable by itself?
yeah
not a function
this would be a function
the equation x = 0.5y^2 + 1.5 would be this curve on its side
are you saying that x = 0.5y^2 + 1.5 isnt a function?
my teacher said to use the vertical line test
and a function is supposed to have only 1 output
wdym?
like the
f(x) but inside the x is a value
and u subsitute the x value in an equation with the x value from f(x)
so what are you trying to figure out?
ya
but f(-x) is a graph
i’m rlly not sure
we did this in class but with a diff equation
and did nothing with graphs
E
oh it means like that
well then the graph is exactly the same
if you sub -x into that equation of |x| - 3
would there be a domain and range for this
yes there is always a domain and range
(-1.3, inf) ??
is there any boundary on what x can be?
wdym by boundary
as in can x be any number, and if not, is there a boundary (or an interval) on what x is
x is approximately -1.286
that doesnt have any relevance to the domain and range of this graph though
yeah

