#help-36
1 messages Β· Page 224 of 1
5
mmm not quite
Rememebr our quadratic is in the form
y = ax^2 + bx + c
And what we have right now is y = 5 - x^2
What is the number attached to just x? (Is there a number attached to x?)
Btw I have to go now unfortunately
0
no
The reason why I am always stressing for you to graph it is because I strongly believe that being able to graph a function allows you to better understand what is going on.
This is especially important when you get to evaluating double and triple integrals, because it is almost impossible to evaluate integrals without actually seeing the region you are integrating.
Once you draw all four equations together on the same axis, you want to find the region enclosed by all of them to get the region A.
Based on the image, that also tells you where the pairwise intersections are.
yes
is it?
Idk how you can evaluate multiple integrals without knowing what the regions are
Well I mean the actual evaluation is probably simple but
Setting up the integrals (arguably the most important part of evaluating an integral) definitely requires that you know what you are looking at
Anyway I'll leave this here as a crosscheck: But, once you figure out the points of intersections, you can substitute them into the original function to get three test values.
can you come later
or are you going to leave me alone and helpless
Sure! If you still need help, I should be on later today
OK. because everyone insists on parametrization and I an going insane dude
I have a feeling your help channel will still be on by the time Im next free, so ill show up then
π
oki
I'll be waiting for u mate

We're not saying this because we want to, we are saying this because it makes the problem significantly easier π
Anyways GL!
@gentle zephyr Has your question been resolved?
@gentle zephyr Has your question been resolved?
@gentle zephyr Has your question been resolved?
@gentle zephyr did you manage to make some progress :D
im hardstuck
Oof
Give me a moment to prepare. Show me what you've got so far
i got stuck at the pairwise intersections step
Hmmmm okay
So, back to what I said earlier,
We have the four constraints: x = 0, x = sqrt(5), y = 0 and y = 5 - x^2
Using these four constraints, we can graph the region that these constraints represent - that's pretty much what we were doing awhile ago.
This is what you had awhile ago, and now I asked you to graph the parabola:
y = 5 - x^2
You told me that the vertex occurs at x = 0, so the vertex of this parabola is (0, 5)
How would you draw this parabola then, given this piece of information?
damn we still on this one, ill still insist on the method i explained twice
@gentle zephyr
@gentle zephyr Has your question been resolved?
yeah we stopped here
yep
igts just an upside down parabola (sad face parabola) where we are moved by 5 upwards the y axis
what is your method
that at the boundaries we parametrize?
yea, and using the gradient
why not lagrange multipliers
cause i dont know how to use them 
well its hears more complicated than what it really is, but we can do it with parametrization and change the multivariable problem to a single variable problem
Have you already found A?
Yes, i know, but like, can you figure out how it looks just based on the bounds
aka, can you find the corresponding curves for boundaries
the boundaries of the region are 0 = x
x = sqrt(5)
0 = y
5-x^2 = y
@glossy zephyr
yeah, and what about parametrization
dunno
also just for myself
parametrizations are of the form c(t) = (x(t) , y(t)) here
We have 3 distinct bounds
so we will have 3 curves
Youll prob want to draw the figure so we cant work it out.
4
nope, just 3
I dont mean the bounds for the xy coordinates
i mean the bounds of the area (frontier)
care to elaborate
Again, have you found how the area A looks?
no, not really, but it seems it will help
we just want max f inside this region and min f inside this region
it is hard to draw the region by hand
tbh its pretty easy, just for the sake of reference
0<x<sqrt5 forms a stripe that stretches infinitely up and down
from 0 to sqrt5
and 0<y<5-x^2 is the region defined from the inside of a parabola up to y = 0.
for them both to be satisfied, you have to take the intersection of both
no idea
A is all the points x,y in R^2 where x is inbetween 0 and root 5, and y is between 0 and 5-x^2
now you should be able why we can define the frontier as three curves
two of them are "curves" which simply satisfy a straight line following the x and y axis
the other follows y = 5-x^2
For the inside, you just use the gradient of the scalar function
for the boundaries you define:
c1, c2, c3 as functions of t and plug it in in your original function
all of them will have polynomial order, once you do that, derive with respect to t, and find the values of f'(t) = 0 for all of them
- the corners
- you can apply the following principle
@gentle zephyr Has your question been resolved?
Renato I thought you understood Lagrange multipliers yesterday
You could at least try trusting your knowledge from yesterday and make some progress
hm maybe renato doesn't have a good conceptual understanding of them yet?
dose any body do physics here ???
I assume so, but trying is always worth a shot, especially when the steps of a solution of a completely analogous problem are easy to find on this very server
Afterall, how does one learn without trying their current abilities?
There should be a feedback loop
the idea was that there is multiple restrictions now, not just 2
but the idea we discussed should still hold?
like should be still the same procedure with the exception we take the pairwise intersections and add those points as potential candidates
yep
absolutely
the issue is. we have 4 restrictions now
Well, anyways
Judging from this image the 4th restriction does nothing, so basically 3 restrictions
And only 3 corners
how?
why cant I use the 4 restrictions even though one is redundant
Sure, use all 4 of them
0 = x
x = β5
0 = y
y = 5 - x^2
I get weird stuff when I intersect first with second
That's because they do not intersect
like, 0 = β5
ok
candidates = {(0,0), (0,5), (β5,0)}
this is all the points I got from the intersections
and of course all this points are inside the region
so do I need to apply lagrange multipliers 4 times?
I already found the candidates from the intersections
then I pressume would need to find the critical points unrestricted and see which ones fall inside the region
and then apply lagrange multipliers 4 times with each of these
g1: 0 = x
g2: 0 = β5 - x
g3: 0 = y
g4: 0 = 5 - x^2 - y
correct
L1 = (x-1)(x-y) + Ξ»x
L1 = x^2 -xy -x + y + Ξ»x
L1x = 2x -y - 1 + Ξ»
L1y = -x + 1
L1Ξ» = x
2x -y - 1 + Ξ» = 0
-x + 1 = 0
x = 0
@lament vale are you seeing this? I get 1 = 0
Okay, so this system has no solutions
Proceed with the next lagrangian
wtf is going onnn
and you guys want me to do this by myself without any help whatsoever
like if I were Albert Einstein
Bro is it your first time seeing a system with no solutions?
no, but is off putting seeing something like this in my second exercise with lagrange
L2 = x^2 -xy -x + y + Ξ»(β5-x)
L2 = x^2 -xy -x + y + Ξ»β5-Ξ»x
L2x = 2x - y - 1 - Ξ»
L2y = -x + 1
L2Ξ» = β5 - x
0 = 2x - y - 1 - Ξ»
0 = -x + 1
0 = β5 - x
I get β5 = 1
L3 = x^2 -xy -x + y + Ξ»y
L3x = 2x - y - 1
L3y = -x + 1 + Ξ»
L3Ξ» = y
0= 2x - y - 1
0 = -x + 1 + Ξ»
0 = y
x = 1/2
one possible candidate is (1/2, 0)
candidates = {(0,0), (0,5), (β5,0), (1/2,0)}
L4 = x^2 -xy -x + y + Ξ»(5-x^2-y)
L4 = x^2 -xy -x + y + 5Ξ» - Ξ»x^2 - Ξ»y
L4x = 2x - y - 1 - 2xΞ»
L4y = -x + 1 - Ξ»
L4Ξ» = 5 - x^2 - y
0= 2x - y - 1 - 2xΞ»
0 = -x + 1 - Ξ»
0 = 5 - x^2 - y
Ξ» = 1 - x
2xΞ» = 2x - y - 1
Ξ» = (2x-y-1)/(2x)
1- x = (2x-y-1)/(2x)
2x - 2x^2 = 2x - y - 1
0=2x^2 - y - 1
y = 2x^2 - 1
y = 5 - x^2
5 - x^2 = 2x^2 - 1
6 = 3x^2
2 = x^2
x = Β± β2
y = 3
so two possible candidates is (β2, 3) ,(-β2, 3)
f(x,y) = x^2 -xy -x + y
fx = 2x - y - 1
fy = - x + 1
(x,y) = (1,1) is another candidate
.close
Closed by @gentle zephyr
Use .reopen if this was a mistake.
at the end my TA said parametrization is easier and preferred
I am a stupid ass
trying to use lagrange when we could always use parametrization
You should prob practice parametrizing the boundaries areas on its own totally beyond the fact of looking for maxima and minima
wdym?
you mean like the borders of the region
being able to find the curves (pametrized curves that is) that make up the border
yeah fair enough
well I still dunno if I like it
like, we needed to use a lot of trigonometry for this exercise he was showing me
and find the angle of some points in the xy plane
I will share it here when I get home
like we were parametrizing this exercise he was showing me and he was struggling in the middle of it
some prof came and show him how to get unstuck
then we did it with lagrange and it was way shorter and simpler
no geometry whatsoever
he still prefers parametrization because it turns into a single variable problem
but when we had to parametrize an ellipse the parametrization becomes trigonometric functions
and in some point or another we had to find some angles
so that was nasty and difficult in my opinion
in the case of lagrange for the ellipse we had a three unknowns three equations system
we solved it in a couple of steps and we found the same points that we found when parameteizing the ellipse but without all that trigonometric jazz
Yeah this is a big reason why Lagrange multipliers are helpful
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
What have you tried and what are you stuck on?
Im stuck on whether when you times the whole equation by 5
do you still use the same denominator
or also times by 5
You should start by subtracting both sides by 7/6
How come you want to Γ both sides by 5?
because i was solving a question similar to this and the equations times the equation by 5
like this
,rotate
In problems like these, you should start by removing any constants in the left hand side
$9m+\frac76=4$
πΈπππππππΒ³
u could times by 6 tho to remove the fraction
Sure, but youβd also have to Γ 6 in 9m too
and that just makes things longer than necessary
Anyway, @onyx canyon, subtract 7/6 from both sides
okay\
Which gets you?
YYeah but iif she really wants to multiply the eqn lol
$9m+\frac76-\frac76=4-\frac76$
πΈπππππππΒ³
You should belooking at the constant 7/6 in the left hand side right now

correct.
and then letβs turn 4 - 7/6 into one fraction.
@onyx canyon know how to do that?
uhh
4/1 - 7/6
and then find common denominator
and then times 4/1 by 6 to get the same denominator
β
24/6 - 7/6
Which would get you?
17/6
πΈπππππππΒ³
what can we do here to get π all alone?
divided by 9
πΈπππππππΒ³
notice the 9/9 in the left hand side. What can we do to it to get rid of it?
correct.
alone
$m=\frac{\frac{17}6}{9}$
πΈπππππππΒ³
you can simplify this further. Do you know how?
well we cant really simplify 17/6
But you can simplify the entire fraction
maybe find lcd between 6 and 9?
$\frac{\frac{17}{6}}{9}=\frac{17}{9\times6}$
πΈπππππππΒ³
you can bring the six down

correct!
oh thank youu
if you want to plug it back into check thatβs always a good idea.
okay!
if your question has been answered you may close the channel with .close
.close
Closed by @onyx canyon
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
for this equation, how do you calculate the uncertainty of r?
given that you have delta v, delta I
Use chain rule to find dr
@pearl leaf Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
hi can someone look at what went wrong? Idk why they got 3-e
@dreamy moon Has your question been resolved?
how is it e-0?
What is 0 times 1
0
Civil Service Pigeon
rip
If you are done with this channel, please mark your problem as solved by typing .close
@dreamy moon Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Wouldnβt the x centroid of the second rectangle with dimensions 270 and 30 be, 240+15=255
Yes
And the Y centroid would be half of 270
+30 to it
assuming the first rectangle contains the base of the second, yes.
I cut the first rectangle into 240 and 30
So Iβm taking the 30 base of the second rectangle
So would it be half of 270, or do I still add 30
Yes you add 30 to get the coordinate
the centroid is a positional value, you still need to add 30
Same thing we did with x
Closed by @fathom imp
Use .reopen if this was a mistake.
β Original question: #help-36 message
So I tried this problem
I made a big rectangle minus 2 right triangles
Rectangle having dimensions of 120 and 150
you should subtract three triangles
Oh I didnβt see that triangle
Is there a diff method or should I continue with this
Btw
For my triangle on the top left corner
I have dimensions 60 for base and 75 for height
My x centroid being b/3=20
And my y centroid being 75+H/3= 100
Is that correct
why do you need the centroid?
The question asks to find the centroid of the entire shape
oh
So Iβm using the method where you find area, centroids, centroid times area, then use the formula to find x and y centroids
So would these forms be correct
I would do three shapes, one rectangle from x = 0 to 60, y = 0 to 75. then a large triangle across the top, and finally one smaller one on the right
Yeah I just changed it to that
I made this
Now my question is, for the triangle 1 thatβs on the top, left face, would the x centroid be 20 and y be 75 + H/3= 100
I feel like the x centroid should be 2/3 of base
the x centroid for triangle 1 should be 40
if the triangle was this orientation x would be b/3, since it is flipped, x is b-b/3 which is 60-60/3 = 40
your intuition is right
Hmmmm
If that triangle was flipped
Upside down
Then the height would be 2/3 h right
Also
For triangle 2
Would it be 60+ b/3
I mean if the triangle was flipped along the y, then it would be in the orientation of triangle 1 in the picture earlier
@fathom imp Has your question been resolved?
@fathom imp Has your question been resolved?
@fathom imp Has your question been resolved?
.close
Closed by @fathom imp
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
u_4 = 13
s_10 = 55
u_1 + u_2 + u_3 .... u_10 = 55
9(u_1) + 37d = 55
thats as far as i got
dβ¬N?
?
yes
K
If both were real there will be an infinite number of solutions but I supose there is only one
Cuz it's THE
Well idk what a common difference is
u_2 - u_1 = d
Oh
the common difference is the pattern of the sequence
ex: 3, 7, 11, 15
d would be 4
yep nvm ur right
So like u_1 +4d=5.5
And u_1+3d is 13
yes
Yea
Closed by @languid cobalt
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
may smn help me learn for my next math argument cus i got really lost plsπ
from wht i undestood the arguments sholud be "differential equations, homogeneous" "Beurnoulli"
here an example ig
Do you have the original problem statement
Translate it to english if you want responses sooner
im scared i might am not understanding wha u jus said
tho i think the thing on top is the start ya
id need smn to explain me the argument thats just an exampleπ
<@&286206848099549185> ?π
oh sorry i jus saw i need to wait 15 mins well 10 mins okπ
What is there to explain exactly
You need to ask a specific question of what you want to know
id like to know if smn would like to get in a call w me or overall make me understand differential n homogenous equations
Well getting someone to hop on a call with you is unlikely
Why not ? It's ridiculous, why isn't there voice channels in this server π
idk i jus hope to uderstand how to make the passages for me to understand
u sure u wouldn call pls?
kinda right nglπ
<@&286206848099549185> ?ππππππππ
@spark pilot Has your question been resolved?
Let $y=tx\implies\frac{dy}{dx}=\frac{d}{dx}\left[tx\right]=t'x+t$ given these re-write the original ode in terms of $t$ and $t'$
fred172
here t is a function of x
yup
oh thx
wait would u be willing to get in a call n explain all to me would be easier for both i think pls?
I'm afraid I can only help you with in chat
oh why are u busy?
do you have any doubts about the method shown above?
hummm ya i don really understand it
i don get how it works
but i don think that thing is tooo needed
watch
I think i need to understand these first
I kinda do but not all n not all the way n i lack of examples
(The pics need to load)π
@sharp parrot
yup
Closed due to timeout
Use .reopen if this was a mistake.
.reopen
β Original question: #help-36 message
\begin{itemize}
\end{itemize}
fred172
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
i ll wait
- Rember how $\frac{d}{dx}\left[A\right]=0$ where A is a constant, when you perform integration we need to write +C when the integral is indefinite
fred172
yes
ok
This page is just a list of rules for integrals
ya ik
mh ya i should be knowing all abt that one page
r you sure u cant call cause this could be so long like thisπ
sorry I must go
omgπ its ok fred thx
<@&286206848099549185> sorry smn else who can help me thxπ
smn who can call would be FANTASTIC
@spark pilot Has your question been resolved?
@spark pilot Has your question been resolved?
Which textbook are you using on your ODEs course?
may u tell me why u ask that cause idk the answer n what ODEs is so if its really needed maybe i get informed abt it
@untold grove
ordinary differential equations
you said you're strugling to understand non homogeneous differential equations
@spark pilot
ahhhhh well i don use the textbook because our teacher doesn use it and its hard to understand what it says seeing what he says
tho i might tell u
oh its italian tho
Well, if you need help with your exercises, you need to clarify it
its italian tho
which topics are you strugling the most?
do you already know integration?
name of my textbook: Matematica.verde 5
a bit ig
id need to restudy this
it should be easy i didn understand sum stuff last time but i understood the most i should learn it fast
would u be avaible to call (that would be fantastic istgπ)
u can even tell me ya in 2 hours or so
maybe, the problem is that it's almost 10 P.M. in here
2 am at my place ahah (im so doneπ ) humm so cant u rn?
just a minute
ready?
YAP
oh i send u a friend req
@spark pilot Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Share your work here lil blud
not necessary at all, it's pretty simple and I just need someone to check if I'm fumbling anything dumb
yeah, the sequence is correct.
Closed by @craggy plank
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
$-25\sin(2\theta) -100\sin(2\theta) -120\cos(\theta) = 0$
I would start by simplifying $\sin(2\theta)$
@icy current
@gentle zephyr Has your question been resolved?
Closed by @gentle zephyr
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
what does it mean with resting on the inside and outside? i dont get the definition of r_i and r_o
something like this
uh whar
the torus is inside the sphere for r_i
but the sphere is contained within the torus for r_o
like
- donut inside and at the bottom of a spherical shell
- donut on the top of a spherical shell
ohh wait hold on im silly the torus is smaller than the sphere
yes
ok ok i think i get it now
so like, if we take the vertical cross section it would look like this?
yeah
Closed by @jagged flare
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
(i + <20>) + H
third isomorphism theorm?
yes
Closed by @warm python
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Channel closed due to the original message being deleted.
If you did not intend to do this, please open a new help channel,
as this action is irreversible, and this channel may abruptly lock.

Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
,rotate
Which one is right?
the first
The top one i presume
Is it the same with logarithmims?
yes
Okay thanks ann
when you apply a function to both sides of an equation it goes on the very outside
Are there any other functions id be applying instead of these 2
As a high school student
Closed by @indigo swan
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
is it 9th grade circles?
Yup
Do yo how to solve?
yes
my internet's acting up sorry if i disappear suddenly
why're they making you solve this then? π
wdym
you'll have to use the theorems, try going over them
Closed by @compact ocean
Use .reopen if this was a mistake.
hold on i'll guide you through this one
β Original question: #help-36 message
im not sure how to motivate this
what properties of isosceles trapeziums do you know?
oh π
well for this one, the one you need is the fact that their diagonals are equal
Well
then you can show that it is either an isosceles trap, rectangle or square
you'll need this
pulled it from https://ncert.nic.in/textbook/pdf/iemh109.pdf
In my country
alright
Yo
I know this
I know inscribed angle and central angle standing on the same arc are equal
And inscribed angles standing on same arc are equal
But idk how to relate it with this question
dw you only need the fact that equal arcs means equal chords
yep
Okay
Then I can easily solve it
Iβll dm you in the morning
Iβll sleep for now
Bye!
Thanks
.close
Closed by @compact ocean
Use .reopen if this was a mistake.
good night
π
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
using this proof from the lecture notes, does that mean the eigenvalues of T* are conj(the eigenvalues of T)?
ya
.close thanks
Closed by @whole halo
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
isnt it clearly positive definite?
like
if we have an eigenvalue of 0 then isnt det A = 0?
what is Delta_k(A)
is it the determinant of the k by k top left submatrix
ah hold up. ah...
and product of eigenvlaues are equal to determinant

isnt lambdan >= 1/lambda_1 * ... * lambda_{n-1}?
okay hm i think i am too tired to answer this confidently
@manic leaf Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
what are some good eample of isomorphic rings ?
Zero divisors ?
huh why did it get deleted
idk man the bot is dumb
i think you already said this, but Z_rs is isomorphic to Z_r x Z_s when gcd(r,s)=1
if you have two isomorphic rings R and S then M_n(R) is isomorphic to M_n(S)
Great thanks
more ?
R x {0} is isomorphic to R
there are trivial examples with renamed variables, e.g. R[x] is isomorphic to R[y]
you think in a trivial course like intro to discrete math they'll count this as an example ?
i dont think discrete math would cover rings at all?
wait what have you gone over then?
cause that would tell you what examples they might use
yeah you will probably just need to know integers mod n and CRT
yea
maybe something super trivial like R isomorphic to R x {0}, but nothing beyond that
would it be possible to define some ring of functions ?
Maybe a ring of idk continous functions frmo [0,1] --> R
oh wait not closed under composition
ring of continous functions from R --> R
?
yeah
wait i don't think she'll accept this but ig i can just be a prick and say
R x R x {0} is isomorphic R x R

C x {0} is isomorophic to C
C x C x {0} is isomorphic to C
if a question is open ended and asks for isomorphic rings use integers mod n
thats a pretty crazy discrete math class tho
fr ? it's the most trivial class i've taken
I studied hard for 10 hours and I went from being 2 weeks behind to 2 weeks ahead
are you in europe?
yea
"discrete math" might mean smth different to you because here discrete math is a very introductory class for 1st year students
just begins to cover proofs, sets, etc.
well that might be true for you as well looking at it
it's 2nd year here
its just rings and fields that is unique now that i look at it
everything else is standard
yea fields and rings is 1.5 lectures, is not much
in a US institution you would only be introduced to rings and fields in an abstract algebra class
discrete math is more for computer science
yea that's why i wish i took this course before abstract algebra lol
would've made my life quite a lot easier
i think it's a problem if you allow functions with zeros
then forget it
the multiplicative identity is f(x) = 1, right?
and if you have a function with a zero like g(x) = x, then g doesn't have a multiplicative inverse
hmm
its not a field
but it is a ring
C(R,R) is a ring
set of continous functions from R to R
@vital kelp actually this gives you another good example of isomorphic rings
if R isomorphic to S, then the ring of functions from R -> R is isomorphic to the ring of functions from S -> S
That jives
continuity is not necessary, by the way
yea i just realized since ring is pretty weak in terms of conditions
plus to define continuity you would need a topological ring

huh?
but they define continuous functions in calculus
for an arbitary ring R, not R as in the reals
right becaouse you need some sort of norm
and topology is all about continuous maps 
generalized
@vital kelp Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
With S(x) = xΒ²-5x+25/2
can you translate
Okk
Wait 2 sec
A) Deduce the factorization of S(x) - 75/8 and its sign.
B) Find the values ββof x such that S(x) β€ 75/8.
.
xΒ²-5x+50/16
Pls do this
B)?
you can do
S(x) <= 75/8
->
S(x) - 75/8 <= 0
and you already know what S(x) - 75/8 is
@dusky idol ?
so you have
x^2 - 5x + 25/8 <= 0
.
same thing
Yes
c2b7
Tes
Yes
@dusky idol Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Yes
Tu connais la règle pour le signe d'un polynome du second degré avec deux racines ?
.close
Closed by @worldly spruce
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
a. In a group of 2000 people must at least 5 have the same birthday?
b. What is the number that must share a birthday?
c. What is the minimum number for 5 people to share a birthday?
I'm not sure how you would exactly get the answer for part b? Nor am I sure if I'm doing part a and c correctly? Am I correct in using 365 for my k (group) to get my b? Because if they share a same birthday, that means they have to share 1/365 days of the year? Thank you.
do you know pigeonhol principl
Very roughly, that's what I was trying to apply but don't know how. Basically if you have n + 1 items, but it has to fit into n groups, then at least 1 of them will always have 2, right?
right apply that to needing 5 people to share a birthday
oh which part is b) you didn't label it in your question
What is the number that must share a birthday?
Sorry, my bad.
yea instead of 5 people sharing a birthday, it's 2000 balls sharing the same 365 boxes
I see, give me a minute, I'm just trying to understand this. So could we say instead of 2000 'balls', we basically are trying to fit in 365 + 1 items into 365 boxes?
something like that. from pigeonhole you get that 366 people, two must share one birthday
Ah I see.
repeat for 365 * 2 + 1, 365 * 3 + 1, etc.
I'm sorry, I'm a but confused as to why we're repeating?
We're repeating until all the items run out?
The pigeonhole principle states that if you have n places to put stuff, and you have more than n items, at least one has to share places with another.
Example. If you have 4 boxes, and you have 5 items, you'd put the first 4 items in a different box each, but now all boxes are filled. So the fifth item needs to go into an occupied box
in your example, you have 365 "boxes", which are each of the days. So if you have more than 365 people, at least two are forced to have the same birthday. You'd repeat this after having each "box" with one person, to have each "box" with two people, and so on
does that help?
Again, sorry if I'm slow, I do get this part I think, and I see what you're saying with the second part, the books shows it too that way. But I guess would that mean it's 365 * number of boxes + 1 = 2000? Am I correct?
it's not an equality, it's an inequality
Ah I see, that's why you'd do ceiling.
if you have 365, they each fit in one day. So they are not forced to share.
if you have from 366 to 365*2, they fit with only pairs sharing. There's no forcing of 3 ppl to share.
Ah ok. And same with 365*3.
so every 365, or fraction, you need another "slot" in each "box"
and that's why the ceiling
so they are basically asking, is 2000 smaller, or bigger than 365*5?
Oh I see, sorry, give me a minute. I'm gonna write this down as a note.
if 2000 is larger, they wont fit, so they need to share
if 2000 is smaller, you have enough "boxes", so they dont need to share
Yes, 2000 is bigger than 365*5.
So you would at least need 6 boxes?
But wouldn't that be the answer to part a, not necessarily part b?
a. In a group of 2000 people must at least 5 have the same birthday?
b. What is the number that must share a birthday?
c. What is the minimum number for 5 people to share a birthday?
Wait wait, I think I see.
If there has to at least be 6 'boxes', that means at 5 must share a birthday.
Right? Again, sorry if I'm still not getting it.
Wait, no, in this case it would be 4?
c is slightly unclear tbh. Is it asking what's the minimum size of the group for 5 people to always share a birthday or what's the minimum size of the group for 5 people to possibly share a birthday
Looks like they mean the first
I don't know, that's just what the question says. π
Okay idk what has been done so far but
But unless 'm wrong, wouldn't it be that there has to be at least 6 people to share the same birthday?
See each day as a box and each person as a ball
If there's more than 365 people, at least one of the boxes must have one more than one ball
That's two people sharing a birthday
Here, I'll just show you what I've done, not sure this is right or not either, I'm stuck on b mainly
Yes.
Ok, nevermind, I'm a dumbass.
And 2 is what you've done
No, you were gonna need to do it anyway for 2
Wait, I'm sorry, I'm confused, how is it 5 and not 6? Won't you divide 2000/365 and find the ceiling?
Do 5 people share a birthday? Yes
How many people share a birthday? At least 6
You would yes
OH MY GOD I'M DUMB
I don't know how I got the arithmetic wrong
Wait, it's 2000/365, right?
No, sorry, nevermind.
I tried checking it again and used 2000/5 instead of 2000/365. But this is what I got for 2000/365 and got 5.47..., if you take the ceiling, it would be 6? So shouldn't it at least be 6?
...slow down you're panicking
Yes
The answer to a is yes
Ah ok.
Result:
5.4794520547945
Ok, sorry.
Cool
I thought a would be 6, not 5.
A isn't asking for a number mate
It's a yes no question
If 6 people share a birthday, 5 people also share a birthday
Ah, admittedly my reading comprehension sucks.
Just ignore one of those people
Lmao issok
Yea no, the sentence makes sense now.
Cool what about the others
Just to make sure, for the third one, I was reading in the book, and you're finding the converse to answer c, right? Just to make sure I'm applying this correctly.
Not sure what you mean by converse
But what you've done is correct
If you have n boxes and you want to ensure at least one of them has more than k balls
You need at least n(k-1) + 1 balls
This is what it says. So yea, from what you're saying I am doing the right thing.
Alright, thanks a lot. I think I get it, so I'm actually doing the right thing, but my reading comprehension sucked so I misunderstood the first part of the question. Have a good day/night. + 1 is the extra pidgeon, n is the amount of pidgeons, and k - 1 (from your version) is maximum pidgeons per hole.
.close
Closed by @fervent eagle
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
i need to find supremum and infimum of Z, how do i do that? i see that on the bottom it's (n-20)^2+something but i dont know what to do next
well no
have you tried anything really?
other than vertex form
i mean i could just guess as in find such n that (n-20)^2 ~ 30 and just check since it's just natural numbers
ok so for the first one you have (n - 20)^2 - 30 so clearly this will have a negative inf and positive sup yea?
but yes that is the idea
right, 1/6 sup and -1/5 inf
i guess i'm tired
thanks you
.close
Closed by @novel nexus
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
How do I continue this proof, I work with the LHS and that results in using the ih to replace lhs with (k+1)^2
$\sum_{i=0}^{k+1}(2i+1)=((k+1)+1)^2$
Axe
did you get this?
you said you were working with the LHS, so maybe you did something like this?
$\sum_{i=0}^{k+1}(2i+1)=\sum_{i=0}^{k}(2i+1) + (2(k+1)+1)$
Axe
wait honestly I'm just not sure hopw to get that last part
I know it'sm the last term, I'm unsure how I can know that myself?
oh you substitute $i=k+1$ into $2i+1$
Axe
you use $i=k+1$ because that's the upper limit of the sum
Axe
OHH
thank you you're a life saver I see what it means now
I'll continue solving it knowing this
thank you!
you're welcome
Closed by @severe robin
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
yo can anyone show me how to solve this question
i js want the answer my teacher taught me i forgot
Draw a right triangle
ok
@peak rivet Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.