#help-36
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How do I do this
do you know how to complete the square?
No
do you know what vertex form is?
Yes
This algebra video tutorial explains how to solve quadratic equations by completing the square. It contains plenty of examples and practice problems.
Quadratic Equations - Free Formula Sheet: https://www.video-tutor.net/algebra-formula-sheet.html
Quadratic Equations - More Video Content:
https://www.video-tutor.net/quadratic-equations.htm...
Can you tell me what it is?
Or alternatively, just watch the video
F(x)=3(x-2)^2 +3
And ok
There we go.
Ok well I will close this and watch the video thanks

.close
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so I integrated and (after a bit of simplification) got ((ln((x^3+1)^n)/(3x+1)))/3 which I assume converges for n values __<__1/3?
@brazen breach Has your question been resolved?
not exactly. I think the full factorized form is not really helping to see what is happening.
wdym
your expression is equal to $n/3\ln(x^3 + 1) - 1/3\ln(3x+1)$ right ?
Lin Xia
from here you can develop this way $\ln(x^3 + 1) = \ln(x^3) + \ln(1 + 1/x^3)$
Lin Xia
and the second term goes to 0
using this you can show that the solution is $n = 1/3$.
Lin Xia
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$$y"-2xy'+y=0$$
water beam
Find the general series solution about x=0
water beam
this is what i got
i want to check if its right im not sure about the factor of a0 and a1 inside the summations if it needs to be there or not
you can check ur answer by putting it back in the ode
it makes sense for there to be 2 parameters to your solution (a0 and a1) because it's 2nd order
hm okay
but does a2k / a0 and a2k+1 / a1 look right
like the / a0 and /a1
if i factor it out
idk, i mean as long as it matches the first line
?? gtfo vie
alright
u used in laugh in my help channels

do not flood my channel with your nonsense
are u sure about the - in first equation
like after x^2/2
good question
i think so
also what if a0 or a1 are 0. ur dividing by 0
but usually we dont choose a0 or a1 to be 0
alright, well that's an edge case. as long as ur aware
a2 = -1/2 a0
a4 = -1/8 a1
so the negative sign is right im pretty sure
at least for this recurrence the even terms a_2n will be negative
but also
[
\text{Solution:} \quad
y(x) = \sum_{k=0}^{\infty} a_{2k} x^{2k} + \sum_{k=0}^{\infty} a_{2k+1} x^{2k+1},
]
water beam
i can write the series like this without factoring which avoids factoring the a0 and a1
how is ur next term + then
its just convention i really mean like +....(- insert term) + (-insert term)
ohh that confused me
cuz if i write it as -.....- it might look like im talking about descending powers but im rlly just adding a bunch of negative ascending powers of x
difference between + ... + and - ... - ?
ur just specifically writing the next term as (- ) not all- the prof may misread it
or per notation same
but u didnt add brackets for first few terms no
If the signs are to flip, the continuation should be made as clearly as possible
So, for instance, a + b - c + d - ... implies the sign flips every other term
But a + b - c + d + e - f + ... implies every third term is negative
If you write a - b - c - ..., you're implying all other terms are negative
bruh take some time off the internet for a bit and get some rest
You can write a +... but that's ambiguous
i can't go outside sorry
the recurrence relation a_2k already has negative signs encoded into it so i think its fine to keep it as +.....+ ?
I said off the internet, not touch grass 
if i said -....- that could be mistaken as subtracting my terms in a_2k which will get me positive signs which is not what i want
you will solve for the general solution and then find the power series
The compromise is to write more terms
Aside from the 1, are all the other fractions here being minus-ed?
but if u leave it like that in exam- there is 100% possibilty of prof misreading it and cuting ur marks
yeah because a_2k generates only negative terms except 1
Then you need a -...
na my prof would know what im referring to im sure
Because the series only continues with negative algebra-terms
(by this I mean -x is a negative algebra-term, even if x = -3 say)
until the prof knows u personally- aint no way
okay ts sign convention isnt what my doubts was about ๐น my doubts is if i correctly factored out the a0 and a1 here in the series
he does
making all the x terms in bracket with - ( x + x + .. ) makes it very neat
On a serious note, this is correct, but for reference, a_2k and a_2k+1 (completely separate) to each other, form a certain sequence starting from a0 and a1.
a0 associated terms are always negative except for 1
also, reminder, the 1 and x can be incorporated to the sums
Maybe, but the 1 there is positive, so that's less viable
we leave 1 out 1 - (x terms)
But that's more clunky, esp. when beam's trying to rewrite this as a power series
Also, doesnt the question ask for the solution at/neighbouring x = 0?
(I suppose you could do -(-1 + ...) though)
topic about + and - notation is brainrot maybe ignore this
isn't your notation already fine?
wait so what form should i keep it in
should i keep where a0 and a1 is factored or
Also, incidentally, googling the question just sent me straight to a video solution lol
https://youtu.be/7w_GdalO9p0 They just left it as an expanded series
Differential Equation using Power Series: y'' - 2xy' + y = 0
#powerseries #powerseriessolution #differentialequation #differentialequations
a_2k is always a multiple (one thats predictable) of a0
i stole it off a youtube video
okay spoilers
my prof wants me to keep it in a series form tho
It's not a spoilers since beam's already got that answer
That's literally this message
Like, i dont want to spoil it, but you can write the sum as
a0 ฮฃ f(k)x^2k
Where f(k) represesnts sequence that arises from the fact that a_2k are all multiples of a0
ohhh wait thats true wait cant i just say a0 ( 1 + sum a_2k*x^2k)
the 1 can be incorporated btw
yeah
You can pull the 1 out entirely, and just have a0 be a separate thing yh
Well not separate, but yk
Heres a small ex. of wikipedia
Again, we keep the a0 and a1 since these are from IVC
which we dont have
Im not precisely sure if f(k) (a_2k) can be expressed in closed form tho.
water beam
wait so are we allowed to write it as this?
make the index n = 0 and erase the +1
oh tru
Notably, its not a_2k, you can write it as a_2k / a0
or "some" f(k)
im not precisely sure that the sequence 1, -1/2, -1/8, -7/240... has a closed form tho.
$a_{0}\left(\sum_{n=1}^{\infty}\left(\frac{a_{2k}}{a_{0}}\right)x^{2k}+1\right)$
water beam
Like, it isnt precisely hard to compute the values from the recursive definition, but it would be neat to have a closed equation for it.
ye would be nice if possible but my prof said for series solutions this is enough for full marks if u can get it down to here
okay anways i think thats all
thank you for the help
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What's your question
can i get some help
You been here for like 2 years, you know how it works
Just state ur doubt and translate if possible
the doubt is howto integrate this with the given region
the translation is not necessary is just a region in a set and an integral
Hint : ||cylindrical coordinates||
Before you ask:
"Why?" Because the function and region has some x,y circular symmetry (x^2 + y^2) and z has easy bounds.
"How?" Look through your notes for what cylindrical coordinates are, try to write your region R in terms of those coordinates, look through your notes again for how you change from cartesian to cylindrical coordinates in an integral.
why not polar coord
Polar is 2D. For 3D you either have cartesian, cylindrical or spherical.
Because
z has easy bounds.
wdym?
Your z is bounded from -3 to 1.
say I want to use cylyndrical coordinates, how to write the integral with this? and what would be the jacobian @blissful meadow
before you ask, dont you have notes on cylindrical? im sure you've had experience transforming variables
if I would know everything I wouldn't be asking for help
have you tried anything at all? like show where you're struggling
Idk how to start
what are your notes on cylindrical coordinates and their transformations?
im pretty sure cylindrical is just polar but you leave z free
meaning (x,y,z) = (rcos,rsin,z)
idk why you are making a big fuss about it @marsh mountain
never mind
anyways
how would you turn the $1 \leq x^2 + y^2 \leq z^2 + 2$ into polar with this, using $x = r\cos\theta$ and $y = r\sin\theta$?
blanketism
.
Please do not ping individual helpers unprompted.
he was asking me a question
no
do you have notes on the jacobian?
its the determinant of the transition matrix
okay
idk
can you calculate the terms?
okay, what do you know about the jacobian
what do you have on what the transition matrix is
can you start this at all
if I would know everything i wouldn't be needing help dawg
we would need to see the change of coordinates as a linear transformation
and the jacobian as a matrix representation of change of basis of a linear map
@marsh mountain
im not saying you need to know everything, but you seem like you dont even make an attempt to do things on your own before asking for help
They're not making a big fuss about it and you don't need to know everything. If you ask for help you should have already made a decent attempt at it, and if you really don't know where to start then the least you could do is be aware of the definitions you used in your course, in this instance cylindrical coordinates, how to compute a Jacobian, how to compute its determinant, how to change variables.
If you get stuck doing one of those things, then that's fine but you should say where you're stuck instead of just saying you don't know where to start. Is it with writing the region in terms of cylindrical coordinates? Is it with computing the Jacobian matrix? Is it with computing the determinant of a matrix? Is it with doing the actual change of variables? Is it with computing the iterated integrals?
you're asking basic questions about what a jacobian is, which is strange because you're being given questions about it. you're telling me you have no notes about the jacobian in your book or something where you can try to discern what you need to do before asking here?
but whatever
Please give me something to compile, for example latex ,tex The solutions to \(x^2 = 1\) are \(x = \pm 1\).See ,help and ,help tex for detailed usage and further examples!
oof
$$\frac{\partial(x, y, z)}{\partial(r, \theta, z)} =
\begin{vmatrix}
\partial x/\partial r & \partial x/\partial \theta & \partial x/\partial z \\
\partial y/\partial r & \partial y/\partial \theta & \partial y/\partial z \\
\partial z/\partial r & \partial z/\partial \theta & \partial z/\partial z \\
\end{vmatrix}
$$
blanketism
where cylindrical coordinates are $x = r\cos\theta, y = r\sin\theta, z = z$
blanketism
can you proceed with this?
yeah
okay, go ahead
cos -rsin 0
sin -rcos 0
.0. 0. 1
-rcos^2 + -rsin^2 = -r
wat
right
cos -rsin 0
sin rcos 0
.0. 0. 1
r
no
do you know your bounds for r, z, and theta?
this is for r
okay
1 <= r <= sqrt(z^2 + 2)
-3 <= z <= 1

no
okay
0 to 2pi then?
why
if we restricted x or y specifically, then we would need to solve for theta
since $x^2 + y^2 = r^2$, then nothing about theta's restricted
blanketism
we just go a full circle
this is hard
$\int_0^{2\pi}\int_{-3}^1\int_1^{\sqrt{z^2 +2}} ze^{r^2} \cdot r drdzd\theta$
blanketism
uff
i hope you can handle integration
we can use fubini
-# that's already Fubini
You can't separate them as a product like this when the bounds depend on one of the variables.
Yes.
,w integral xe^x^2
reverse chain rule
u mean u sub
call it how you want it lol
kind of funny integral cause you encounter twice the xe^(x^2) form
-# (For the record Fubini just says that you can take your integral over are region R with respect to dA or dV and rewrite it as iterated integrals like you have. That's all it says. In the specific case where the region is a rectangle/product of intervals AND the function can be expressed as a product of functions in terms of the respective variables of integration only, then you can just rearrange stuff and it becomes the product of three integrals.)
oh this shit is tough
@blissful meadow @drowsy epoch
,w 2pi * ((e^3-e^(11))/4 + 2e)
can the volume be negative?
You're not computing the volume.
In this specific case there is no physical context.
If f(x,y,z) gave some sort of density, then you'd get the mass, just like in your problem from yesterday.
where is the mistake then
There is no mistake.
The volume can't be negative. The mass won't be negative too, provided the density is chosen such that it's always positive (which is the only way it makes sense physically).
In this case, as I said, there is no physical context. You computed the integral. That's it.
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Consider the unit circle $C$ defined in the real plane $R^2$ as:
$$C={(x,y)\in R^2 : x^2+y^2=1}$$
Let $T_\theta$ be a rotation of this circle in the counter-clockwise (positive) direction by an angle $\theta > 0$. It is given that $\theta$ is not a rational multiple of $\pi$ i.e. $\theta \notin \pi Q$\par
Let $M (1,0)$ be a point on this circle.
- Prove that $T_\theta^k(M) \neq M$ for all $k \in Z^*$\par
- Use the Principle of Mathematical Induction on $n\in N$ to prove the following statement:
For every $n\in N$ there exists an integer $m\in N$ such that the length of the arc of the circle extending between $M$ and $T_\theta^m(M)$ does not exceed $\theta\over2^n$\par - Prove that any segment (arc) of the circle $l$ no matter how small, will contain an infinite number of points from the orbit $l$, where:
$$l={T_\theta^n(M),n\in N}$$ - If we represent the unit circle in complex form, prove that the orbit L constitutes a subgroup of C
Amer
@sour copper Has your question been resolved?
Can also try #real-complex-analysis or #groups-rings-fields
ain't got no perms
@sour copper Has your question been resolved?
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hello, could someone please help me with these two questions?
Given that:
AB = BC
AF = FE
CD = DE
using point X, where AD = BX and AB = DX, prove that vector BE = AD + CF
must this triangle be an isosceles triangle?
thank you and apologies in advance for the poorly drawn diagram
ok I'm not entirely suer on my own logic here
so you have AD=BX so BE=BX+CF
notice that BE=BX+XE, so we have CF=XE which we have to prove
going back we have BE-BX=XE so CF=BE-BX, express BE as the sum of vectors including CF
so trying to find XE = CF
for 2. I have no idea if you can prove it is, maybe consider that centroids don't really move when triangles are changed so no
yes, you go back with BE=BX+XE -> BE-BX=XE=CF
how did you arrive at the conclusion that XE = CF?
AD=BX
AD=BX, BE=AD+CF => BE=(BX)+CF=BX+CF
BE=BX+XE
hmm isn't that familiar
AB=BC, AF=FE, CD=DE tell you that B, F, D are midpoints of AC, AE, CE respectively
also that does NOT force triangle ACE to have two equal sides, so large triangle need not be isosceles
ahhh, after writing it down it makes sense!
and we dont know it must be isosceles?
yeah, i understand theyre midpoints, just wondering how to use that to prove q1
as in question 1 proves question 2 or the fact that their midpoints proves question 1?
nono, that im just curious about
so triangle ACE DOESN'T have to be an isosceles?
proof should vector ?
wdym?
or go with undesirable say
wdym by proof should vector or go with undesirable say? as in does it have to use vectors to prove it?
should vectors be used in the proof, or is that, say, undesirable?
it doesnt really matter, the second part of the question im just curious about. you dont have to use vectors, I just want some sort of explination to whether or not AE has to equal CE
sorry for the ping, I have a follow up question
you say that BE = BX + CF and BE = BX + XE, therefore CF = XE
but we dont know whether or not BE = CF + AD is true or not, so doesnt that mean we cant compare the two? because although we know that BE = BX + XE is true, we dont know that BE = BX + CF is true or not?
oh yeah, nw. just want some sort of explination
name explanation of what, maximally concretely
just an explanation of whether triangle ACE has to be an isosceles triangle with AE = CE
and this^
@fluid river Has your question been resolved?
<@&286206848099549185>
pls help with this
counterexample
A=(0,0) C=(2,0) E=(0,3)
then B=(1,0) F=(0,1.5) D=(1,1.5)
so
AB=BC=1
AF=FE=1.5
CD=DE=โ(1ยฒ+1.5ยฒ)=โ3.25
and in triangle ACE
AE=3
CE=โ((2-0)ยฒ+(0-3)ยฒ)=โ13
equalities only tell you that B F D are the midpoints of AC AE CE resp.
(triangle is isosceles only when it has two equal sides)
sorry, let me draw this out to visualize
(my bad counterexample is worst way to state something, but anyway may be helpful a bit still)
sorry im currently really confused
you just solved for CE & CD, but you didnt prove that BE = AD + CF. didnt you just- create a triangle? you know that BFD are midpoints, but you never proved that BE = AD + CF?
also, could you explain whether this is correct or not? Im still not sure that I understand the first part of the question
someone please help, I'm still so confused๐
you mean vectors?
yeah, how vectors BE = AD + CF
both equations must already be proven, if you asking this, then, yes
Im trying to figure out how I can prove that BE = AD + CF, and the person ealier used BE = AD + CF to solve for CF = XE. but since we dont know whether BE = AD + CF is in fact true, isnt the whole proof invalid? we cant say that CF = XE useless we state we know that BE = CF + AD, which is what were trying to prove.
right......?
i feel like im more confused than when we started
if it helps, can we go from the top again? how does vector BE = AD + CF?
im not sure even in what i myself sayin
i tried to help
i don't saying proof itself tho
i also think that your proof may be better than mine, so i will refrain, sorry
i think i helped at least btw, sorry
um, its ok, thanks for trying though, appreciate it
----------------------------------------------------------------------------------------------------------------------------------------------------------
just gonna copy and paste my question again, clean slate, someone please help me, I feel like I havent gotten anyway in the past few hours
Given that:
AB = BC
AF = FE
CD = DE
using point X, where AD = BX and AB = DX, prove that vector BE = AD + CF
must this triangle be an isosceles triangle?
FE?
AF = 1/2 AE.
Do the same, AB = 1/2 AC.
DE = 1/2 CE.
Now, BE = BC + CE.
Which is?
BE = BC + CE.
Similarly, CF = CA + AF.
You want the mid segments.
Then since CA = -2AB, AF=FE, as well as BC=AB, you can adjust those 2 equations.
so CF = -2AB + FE and BE = AB + CE?
We also want to show AD + CF = BE.
But AD = BX.
Then triangle law somewhere here.
triangle law? so like BC + CE = BE?
well
AD = BX, so we need to check if CF = XE
so if CF = XD + DE
CF = CB + BF
so does BF = DE
BF = FE
but FE = DE only if triangle is isosceles right?
@ornate token?
<@&286206848099549185> someone please help explain, I havent gotten anywhere in the past few hours ๐ . I'm sorry for pinging a second time, but idk what else to do.
Is anything else given ? Like BE being perpendicular to AC or any other info?
nope
just that FBD are midpoints
do you have to assume that theyre perpendicular? that would make it isosceles right?
Wait listen
Let's assume some vectors
Say that AB vector is a
And then BC vector is in same direction
So BC vector would be ?
a as well
Yes good
Now say that BE vector is some b
Okay ?
Ok so
AE vector
If we would write it
It would be ?
-a+b
(a+b)/2?
AD = 3/2 a + b/2
BE = CF + AD
b = 3/2a + b/2 -3/2a + b/2
b = b
OHHHHH
Yesssss !
hmmm, i wonder why x is included then
now i wonder if there is a way i can use x in my proof
okok
thank you so much
ive been suck here for like 3 hours
trying to do this
i really appreciate it
My pleasure!
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can someone help me with part g i have no idea what im doing
it is asking you to graph g(x), using the info you get from parts a-f
Using the information from the previous parts, we should have all defining features of the graph, x,y intercepts, maxima / minima, etc.
Just put it all together to sketch the graph
i have no idea how to sketch a graph
Plot the points we do know first
This calculus video tutorial provides a basic introduction into curve sketching. it explains how to graph polynomial functions using the signs of the first derivative and the second derivative of a function. You need to identify the critical numbers and potential inflection points in addition to the concavity of the graph. You need to combin...
take a look at this, a visual representation will probably help you better than just words
so like (2,-16) etc
thanks
Yea
And just โconnect the dotsโ in smooth way
Making sure that:
You have the concavity of each part correct
for a small interval like this just connecting may or may not work, but for larger intervals you'll definitely want to make sure of your concavity and intervals of inc/dec as the other helper mentioned above
and well you'll get all that information from parts a-f, of course.
show what you have right now, it definitely won't ever be perfect but it'll get better as you practice it
no worries go ahead and make a rough sketch of what you think it'll look like to the best of your ability and send that
that looks very good actually, just try to make it a smoother curve going from (0, 0) to (3, -27)
but you got the basic idea right
,w graph x^4-4x^3 from x = -1 to 5
okay will do
thank you very much
ofc! your sketching will get better as you go on, just keep up the practice :)
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A round robin tournament has $2n+1$ competing teams, in each game the outcome is always a win or a loss. For teams $X,Y,Z$, call the set ${X,Y,Z}$ "circular" if $X$ won against $Y$, $Y$ won against $Z$, and $Z$ won against $X$. Determine $\$ $(a)$ the minimum amount of circular sets in the tournament $\ (b)$ the maximum amount of circular sets in the tournament
Copter
Did you finish the geo?
which one
It's not that difficult
can you dm me?
You just need to look at something
Ofc
^
Complete Directed Graph?
wuh..
Are you familiar with graphs?
The teams are the nodes and the games are the edges
@lime crest Has your question been resolved?
uhhhhh
Might've overflown you with information my bad
What do you think about the problem tho?
no idea man
Hmm...
We should try looking at small cases
Maybe we could find some patterns in the results
n=1?
@lime crest Has your question been resolved?
@lime crest Has your question been resolved?
you should think about small cases for (a) because there is a construction
hmm you haven't answered Erebus for 2n + 1 = 3
is there something that's confusing you
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I need help understanding how to get the points for this -1/3 (x-5)^2 +1/2
wdym points
So far I have the point (5,0.5)
For graphing the coordinates
substitute values of x into the expression
that's it
y=-1/3 (x-5)^2 +1/2
I know but I get confused midway through
you got your vertex (5, 0.5)
can you show where you worked up until?
now just find values around it and plug them in
if you have the point 5 as your vertex, that means the parabola either goes up or down around it with that point as your minimum or your maximum. so if you have 5 as your "midpoint" then plug in values like 4 and 6, then 3 and 7, etc. into your function
Ok .close
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is this reasonable or did i miss the point or do somethin weong
this question felt very easy and i feel like somethings wrong
you seem to be assuming that P is linear instead of affine
in general, can't it also change F?
i dont know
what's your definition for affine transformation?
@keen hare Has your question been resolved?
when you multiply a solution of a differential equation by a matrix P (made up of eigenvectors) to get a simpler equation with the same shape
isn't that a linear transformation?
an affine transformation is more general, it's a translation composed with a linear transformation
then i guess i dont really understand affine transforms
how would you start with this problem
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im only stuck on a very small part in this
Let QK intersect RM at F.
im trying to show that QMFA is a rhombus
i know that DEM is equiv to QAM, and NEQM is a kite, all is left is to show that <QMA = <AMF
@lime crest Has your question been resolved?
<@&286206848099549185>
bmo?
wuh
@lime crest Has your question been resolved?
i got it, i think
Let H be the foot of the atitude dropped from R to BC. Let RH intersect QM at G.
i claim that R,G are reflections of eachother on MB
and rhen you can just angle chase, i think
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also BN, MQ intersect on (RHB) which is cool
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how can i fill in the variables such that F become fields (not sure that's the right translation for kรถrper) ? i know the solution but i don't understand how to get there. the only thing i can understand is how to get that in ๐ฝโ a is not equal to 1
?
the spam today is so strange, there are places where you could ask where people care about such edits, why do you ask in random maths help forums instead
This is not the place for that
nice
Please delete.
Do not spam please.
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This channel is only for on-topic discussion. Please take casual conversation to #discussion or #chill.
Hmm, b would just be 2+2 but what's that mod 3
"but what's that mod 3" i'm not sure what you mean by that. i mean, i know what mod 3 is but i don't see why you bring it up
wait, no, i only know mod with two parameters but mod 3 only has 1 parameter
that sounds familiar but i don't remember that.
i thought i should somehow use the qualities of fields to figure out a solution
Well you only need commutativity and that each element appears once per row and col
i don't know why each element only appears once per row. for plus i know there must be an inverse element so there must be 0 somewhere. for * i know there must be an inverse element as well so d must be 1
like, talking about F3 for now, i want to get that done before moving to F4
Because when you add and multiply u want the result to be unique
Yeah
you can think of the elements of F_3 as being the remainders of numbers when you divide by 3
so then $\mathbb{F}_3 = { 0,1,2}$, since those are the only remainders that can result from dividing by 3
TestTickler
and so addition respects the fact that these are the only possible "outputs" over mod 3 ($\mathbb{F}_3$)
TestTickler
so, any time i have the same thing twice i could do something like for example
0+1=1=1+1, therefore 0=1 which contradicts that F has 3 elements ?
well 1 + 1 is just 2 right, but 2 divided by 3 just leaves a remainder 2
so it still stays the same
but when we do 1 +2 = 3, 3 is a number that when divided by 3 leaves 0 remainder , so then 1+2 = 0
you essentially just compute the operation like normal, and then look at what remainder is left with respect to dividing by the size of your field
that is your answer for the variables
-# Randomly jumping in, but yes, field is the correct translation for Kรถrper here 
Yeah should work
can anyone give me the full pic of this problem plssss
However ur reasoning for d is weird
We know it has an inverse, the question is what the result would be applying it
my thinking was 2*x = 1 and we know it's not 2*0 or 2*1 so it has to be 2*2
Either you do that by mod 3 or rule 2 out by the uniqueness property
Why 2x=1?
because there exists some inverse element for 2 for *, otherwise it wouldn't be a field
i mean, that does happen to me more often than i'd like so it was a fair assumption
I was js 2nd guessing myself
IF_4 is a bit tricky because there is not really a natural choice like before
those should be all the possible cases for a,b,c, if i'm not mistaken, i'm trying to see how that interacts with d,e,f right now
typo
I am not quiet sure on this one, there seem to multiple choices possible?
-# Jump back 
i'm pretty sure those are all possible options
What does the solution say
the second option from the top, a=0,d=0
i'm assuming there is only one solution but i just noticed i don't actually know if that's the case
Hmm
Even if we said 1+2=3=b then the choices for a and c need something too
Guess you can choose a=0 instead of 2 because we don't want to do mod 4 here since Z_4 isn't a field
But that's circular idk
Z_2 x Z_2 would make sense for the + table
@ember peak Has your question been resolved?
I am sure that the choices for IF_4 are based on Z_2[x]/(xยฒ+x+1)
i am considering going to sleep. luckily the task is just to find some solution, not to explain it, so i would be fine with figuring out the reason at any point between now and next week at this same time
Ok
unless you had some train of throught going that could help here ?
fwiw I don't think it helps since it would dive too deep into abstract algebra
what does fwiw mean ?
for what it's worth
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can someone explain what these B and D stuff r i dont get linear transformations
its something like i plug B into T and then idk after
In matrix notation
[ \begin{bmatrix} 1 & 2 & -1 \ - 1 & 0 & 1 \end{bmatrix} \begin{bmatrix} a \ b \ c \end{bmatrix} = \begin{bmatrix} d \ e \end{bmatrix} ]
corresponds to the function
[ T\big(a(1) + b(x) + c(x^2)\big) = d(1,1) + e(0,1) ]
clรดud
so the idea is that you do a matrix multiplication with column vectors, but those column vectors are really just "coordinates", i.e. coefficients of a linear combination of the given bases
what about B
in all these problems they all got diff stuff and sometimes u use them sometimes u dont i dont get it
if the vector spaces are the same then you can use the same basis for both the input and output
so you always multiply a vector representing coefficients of a linear combination of B by the matrix to get out a vector representing coefficiennts of a linear combination of D
i dont get it so i plug each thing in B into T?
to be honest i'm not sure what they actually mean by "action of T", does your textbook define it somewhere?
i dont either but i mean in general for linear transformation problems how do i do them
what textbook is this?
nicholson-2023A.pdf
well from reading the textbook they actually do seem to want it something like this
but you actually do the matrix multiplication to find a formula for d and e in terms of a, b, and c and then simplify
because by "action of T" they seem to mean "formula for the output given a generic input"
but for linear transformation r all of them pluging B into T, and then plugging D into those answers?
well you always plug in an arbitrary linear combination of B into T, do the matrix multiplication to find the coordinates of the output given the coordinates of the input, and then turn those coordinates into a linear combination of D
can u give an example i cant find any
where did the 4 matrices from B go. it became v? i dont get what T, M_DB ,C and all these letters stand for
all of this notation is explained in the textbook but C_B is the coordinate vector representation of a vector with respect to B
that means if a vector $\vb v$ can be written as $$\vb v = \bmat{ a & b \ c & d }= a \bmat{1 & 0 \ 0 & 0} + b \bmat{0 & 1 \ 0 & 0} + c \bmat{0 & 0 \ 1 & 0} + d \bmat{0 & 0 \ 0 & 1}$$ then it's coordinate vector representation is $$C_B(\vb v) = \bmat{ a \ b \ c \ d}$$ (note how it's just the coefficients of the linear combination)
clรดud
$M_{DB}(T)$ is the matrix defined so that multiplying the coordinate vector representation of $\vb v$ wrt basis $B$ gives the coordinate vector representation of $T(\vb v)$ (the output of the transformation given input $\vb v$) wrt $D$
clรดud
is this even english im so cooked
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When the global minimum is satisfied, what is the value of f'(x)?
But how do you find range of k
I got this but I donโt think itโs correct
its correct
u can try plotting the graph online to double-check
But it asks for the range of k
Oh I think the range of k values is for the other parts
Alright all good thank you
these are the answers @ruby crypt
dont know how they got less than
@sand barn can u help pls man
I misunderstood the question sorry, the question is asking values of K which has global minimum at x = 1
so its not limited to -2e^2
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A block of wood of mass 10kg floats on water density of wood is 600 and that of water is 1000 find the buyount force acting on wood block
So i calculated the upthrust using the formual row g V that resulted in 163.33N and the book says the answer is 98 N is there sm issue or point i am missing
The block of wood is in equilibrium, because it's has not net force acting on it. For the buyount force must just counteract the weight force
Given that is floats, but it does because its less dense then water
But upthrust can be more than its weight?
No, or else it would shoot off into the sky
np!'
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Iโm confused by the answer key for 21 because I got <-2/SR20, 4/SR20> and why is it U/|U| and not just |U|
Iโm not sure what that means
youre just dividing by the magnitude/length of the vector
Oh kk
like a unit vector is just the vector itself divided by how long the vector is
Iโm not sure how to do the a part of this question
Because where not given an angle
do you know what component form is
you can work with the X and Y singh I guess?
they are both positive so the must be vector in the first quarter
๐คท
@static oak Has your question been resolved?
Try writing them in i,j form
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Hey <@&286206848099549185> I am having hard time getting the logic behind it
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oops wrong command
What ?
read the bot's message
if your q remains unanswered for 15 mins then you can ping helpers
Oh sorry
What's the issue in this problem
Oh I m having problem on creating equation for this prob
what do you understand from the first sentence?
Nothing like I m trying understand what it is saying but I m just getting zoned out
This question is in my native language but still I can't get it for some reason
Hindi?
has to be hindi
No
nvm
I see.
Let's consider Nabil's present age to N, and Shuvo's present to be S. The question begins when Nabil's age was the same as Shuvo's.
"was" So, we are talking about NโS years ago.
But it belong to same language family
Do you get this much?
Bhojpuri?
Bengali
oh cool indian
Ah. I see
Erm m not indian
Why N minus S
If we are talking about them being same
Where?
where
Suppose Nabil is 30, and Shuvo is 20.
So when Nabil was 20, Shuvo's age must be twice of 30.
So Shuvo must be 60
Which is not possible
fit in with any age
Wait so is the problem with Google translate
Call this is my question from my like government textbook
if u still solve it u get an answer
cuz i got an ans
To be honest I didn't get the question
Let Nabil's present age be $n$ and Shuvo's present age be $s$.
Assume first that Nabil is older, so $n>s$.
The statement says that when Nabil's age was equal to Shuvo's present age, that was $n-s$ years ago.
At that time:
$$
\text{Nabil's age} = s
$$
$$
\text{Shuvo's age} = s-(n-s)=2s-n
$$
According to the condition:
$$
2s-n=2n
$$
$$
2s=3n
$$
$$
s=\frac{3n}{2}
$$
This implies $s>n$, contradicting the assumption that Nabil is older.
Now assume that Shuvo is older, so $s>n$.
The statement requires a past time when Nabil's age was equal to Shuvo's present age $s$. But if $s>n$, then Nabil has not yet reached age $s$, so such a past time cannot exist.
TheAstorPastor
Like I have done other math like linear algebra or like quadratic formulas I can get that but I can't get like questions that are in like constructed with linguistic logic
well even if it isnt valid we get the answers that balance those equations even if it isnt logical
Okay then I will give the question with my native language you guys translate it because this question is from my government text book
ok
chatgpt says,
When Nabil's age was equal to Shuvo's present age, Shuvo's age was three times Nabil's present age. When Shuvo's age becomes equal to Nabil's present age, if the sum of their ages is 63, what are their present ages?
uh
gemini says "When Nabil's age was equal to Shuvo's current age, Nabil's current age was double the age Shuvo had at that time. When Shuvo's age becomes equal to Nabil's current age, the sum of their ages will be 63. What is the current age of each?"
and thats copilot
Ok
2:1 rules. that translation is correct i think
do we have bengali helpers here?
So is still the answer illogical
lemme read it
I can get the answer from YouTube but they will not like tell me the logic behind it so I am here to understand a logic actually
rather than error in the q its prob error in the translator
i can read hindi its a little different though
yes please
zavier locked in W
yess
new info : zavier is from wb
google translate says this
oh nvm that was the original post lol oops
Yeah that's correct
Ye
ok thanks
Cute didn't know I was being regionally profiled
Anyway leaving this to the helpers who were here already ๐บ
yea
So the question is contradictory enough to be wrong as a answer?
so. @cinder vapor let's suppose nabil's age is x, and shuvo's is y. let's take the first condition to be z years behind
pastor can do the rest
Okh
Then ?
so. can you convert "Nabil's current age was double the age Shuvo had at that time." into an equation
its a joke ๐
-# so was mine lmao
fair
So x = y- z?
what are the present ages of nabil and shuvo?
X and y ?
then what will be their ages z years ago?
X-z, y-z?
ok great. now the question reads when nabil's age was equal to shuvo's current age.
so nabil must be older right?
Yea
what will be the difference in their age?
X - (y-z) = z years
huh? the age of nabil is x. age of shuvo is y
so difference should be x-y
2x = y+z
Oh
Nabil's current age = $x$
Shuvo's current age = $y$
The difference in their ages = $z$ (where $x - y = z$)
TheAstorPastor
Okh now I get it
"When Nabil was Shuvo's current age ($y$)," the time passed was $z$ years ago.
TheAstorPastor
<@&268886789983436800>
Okh
mrbeast aint getting to us that easy
Go it
can you convert the condition, which is "Nabil's current age was double the age Shuvo had at that time." into an equation now?
Mrbeast will receive $10,000 if they solve this question.
2y =x-z?
not quite.
what's nabil's present age again?
2y = x+z because they need to be equal.
X+y = 63
Y
Oh
hmm. well, yeah that's correct as well. can you pick from here. i guess that's an easier way to approach the problem
i gotta go
mum's calling me. prolly for dinner
Okh bye
Wait how if x is nabils current age and y is shuvos current age
Wait imma come back after 10 minutes ig
Let me think about it for a while during that time.
I didn't fully understand the question.
why we using ai bro ๐ฅ
<@&268886789983436800> using ai to help
I don't understand the question.
then js let some1 else take over
dont use ai
Please do not trust ChatGPT or similar AI tools for mathematical tasks, as they often generate output which "sounds correct" but has numerous factual or logical errors. Use of these AI tools to answer other people's help questions is strictly against server rules (see #rules).
Is using AI prohibited?
Yup
yeah
Yes and is usually a bannable offence
if users want to see an LLM's output they can open chatGPT themselves
I'm new to this server, so I didn't know what I was doing, and I apologize.
ARROW
Dw, just don't do it again or else you might get a less nice mod responding 
lance goat
๐
@cinder vapor you there?
I m back
let me see
Yes
ight
yea i saw that
let N be nabil's current age and S be shuvo's current age
Shuvo's present = Nabil's then
Nabil's present = 2(Shuvo's then)
(Nabil's present) + (Nabil's future) = 63
so @cinder vapor what were their ages (N-S) years ago
so basically this is the info
is that what im understanding correctly?
not fully correct
like what the hell are the timestamps ๐ญ
shuvo's age in the future + nabil's in the future = 63
yeah
Okh
but since shuvo's age in the future = nabil's present
ngl this q hella confusing
yea ngl
@cinder vapor
Fr trig seems less confusing
this thing algebra
Wha?
