#help-4
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Do u have a take?
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This example lost me after defining the possible isomorphisms, is there a typo when they are explaining a_3?
Branshi
I wouldn't be suprised, there are so many typos in this book
I wonder if i got a bad edition or something
is that because
mmm I see
what do you mean by
alpha_3 is well defined
since x mod 10 = y mode 10 implies 3x mod 10 = 3y mode 10
Im not seeing why this part is here
generally when you define a function you have to check that the "formula" actually always gives the same result, no matter in which way you write the input
for example, say I define a "function" f on fractions as f(p/q)=p
then this wouldnt be well-defined
cause 1/2=2/4 but f(1/2)=1 and f(2/4)=2
similarly I could define a function f:Z_10 -> Z by f(x) = x
but then this is also not well defined
cause f(1)=1 and f(11)=11 but 1=11 in Z_10
so the question here is, if x=y in Z_10, is then also 3x=3y in Z_10
to which the answer is yes
ok that makes sense thank you
I'd just like to drop in to make this comment slightly more concrete
Whenever you have a function on a domain that is defined using equivalence classes, you want the function to take the entire equivalence class to the same output. ie., you don't want it to depend on which representative you choose
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I am trying to find the voltage across each voltmeter in the circuit shown. I have currently come up with the answer 3V in the top and 9V in the bottom,, since as current leaves the 9v battery, it can lose 9v and return with 0v, and as it leaves the 12v battery, it can lose 9v then 3v and return with 0v, however, I am not sure what would happen when current from the 9v battery loses 9v and then goes towards the 12v battery, surely it would then have -3v as it reaches the battery, and this doesn't make sense. Can someone help please
there's nothing wrong with a negative voltage
negative potential energy is fine
if we define there to be 0J potential energy on the ground, there would be positive potential energy above the ground and negative potential energy in a hole in the ground
so would there be some charge/electrons with 9v and some with 12v going aroudn the circuit,
and after going through the resistor, some of them would have 0v and some would have -3?
we should think of potential as a function of position. every electron in a given position has a potential energy according to the electric potential there
Yo twin whats sinus bruh😭
also if that is the case that voltage can be negative, how do we konw what the voltages are
we can arbitrarily set one point to be 0V and then calculate the electric potential at every point in the circuit from there
I could now set them to be arbitrarily large and it would be fine since it can be negative
but how do you decide which position that is
it doesn't matter really
for example here where would you start from
like if you had to approach this problem with no extra info
because what the voltmeter measures is voltage difference which will be the same no matter what
which point would you pic
so pick somewhere that seems convenient
so just to clarify I pick somewhere where the potential difference should be 0?
i would probably pick the right side just because most voltages would be positive
where the electric potential itself is 0
what does that mean
we can define the electric potential as the potential difference with an arbitrary reference point, which we decide to have 0V. the electric potential difference between two points is then the difference in electric potential
it's like gravitational potential energy, where we decide on some reference height to have 0J potential energy
oh ok
but wouldn't that mean that it can't be zero for all paths
like if i picked the right side before the resistor to be zero
some of the charge would reach it with 0v, but some would reach it with 3v
so how do i pick a reference point which will always have 0
the voltage of an electron will be the same regardless of the path taken
but won't the different batteries provide different electrons with different voltages
yes but the resistor will make up the difference
that's how you can solve for the voltage across the resistor in the first place
so then how can I answer this question, since the voltage would be different depending on which battery the electtrons have come from
it doesn't
that's what you need to use, the fact that the voltage doesn't depend on path is how you can solve for the voltage at each point
so would it be ok for the current to reach the 9v battery with 3v
if they came from the 12v battery originally and didn't go through the second resistor
can you draw the path you're imagining here?
maybe it would help if we labeled all of the nodes on this circuit
if we set Va = 0V (just as an arbitrary choice), can you figure out what Vb and Vc are?
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hi, can someone help me with this integral? i don't see any undefined integral formulas for 1/ctgx or ctg x^-1
the first half of it i understand but i dunno what to do about the 1/ctgx
can you rewrite 1/ctg x into a more familiar form?
ctg = cot ?
yeah
? bring it to -1 power
like maybe expand it out in terms of its definition with sin and cos
and simplify that
$\cot(x) = 1/\tan(x)$
Médicis
so it would be cot x^-1 = 1/tan x^-1 ?
yes, so tan x
=x/tan x?
Médicis
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Discrete maths question
Above is the question and below is the solution
I dont understand what the solution is saying
its disproving by giving a coutner example
it shows no z can satisfy this
37.5 isnt in N
because such a z would have to be not an integer
the exercise is claiming "for any two natural numbers x and y, we can find another natural number z such that x + y = 2z" but for x = 38 amd y = 39, the only real number satisfying that equation is 37.5 which is not natural, so z can't exist
Ah true
But I still don't see how we can just disprove with just 1 counter example
A proof must hold for any possible x and y
Ahh yeye you're right
the exercise was claiming it's true for all possible x and y, so it would be false if it's false for even one x and y
"All cows are brown" is my statement
You can disprove this by showing me a white cow
You don't need to show me multiple white cows
it's like if i say "it will rain every day next week", if it doesn't rain on Wednesday then i must be incorrect, regardless of whether it rained or not any other day
OK I think I get it now 🙂
Thank you, you all explained it really well!
❤️
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Help in evaluating the Efficient Frontier Equation for a portfolio
ki are random variable?
i'm not sure
ik that w is the the percentage of the stock in the portfolio tho
and the omega_i is the standard deviation of the stock
<@&286206848099549185>
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how to solve the koinsberg bridge theory
@fathom narwhal Has your question been resolved?
no
discrete maths
?
There will be a route that crosses every bridge exactly once if and only if the multigraph of the koinsberg bridge has an Euler trail.
so is it solveable
yep
can u draw me a pic
sure
i have been pondering on this question for 3 years
let’s get it down today
do we have to use fancy math?
Nope you just need to know the definition of Euler trail
ok
It’s proved by Euler
ok
Yeah
i searched it up
,rccw
all good?
but i dont know if it is still solvable or not
Wdym?
you just said if there is an euler trail
Then it’s possible
but is there
But there doesn’t exists any Euler trail
<@&286206848099549185>
Thus it’s impossible to across exactly 1 time
He's already helping you
It’s solved by demonstrating the impossibility
but from point d to point b there is an euler trail
It’s not a theory it’s a problem
Eulerian trail exists in a connected graph if there are exactly two vertices with an odd degree (number of edges connected to them), or if all vertices have an even degree
There are 5 vertices with odd degrees
Thus it’s not an Euler trail
cant you chop it up
That’s clear enough, @marble arch
Go help him
You got to know the conditions for Euler trail man
I think you explained it well enough already
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!test
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Hi what do you need help with
Life
Living
Hi, welcome to the server
Sorry that’s above my pay grade
Enjoy your stay!!
That's unfortunate
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hey so I'm really bad with graphs and I just wanted to double check, is this answer correct?
careful: x = 1 is not the turning point
if you fix x = 1 and replace it with the correct value, you'll get the answer
its not 1
its prolly half (by observation)
so like the fn decreases from x belonging to half to infinity
yeah, x = 1/2 is what I'd also expect
Zoom in :))
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can you give brief explanation that why tan5x can be written tan5x = tan(pi/2 - 2x)
it can't be tan 5x
How am i supposed to go about these type of questions
The example no.27
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in my textbook to solve the equation tan(5 theta) = cot (2 theta)
it is written that this given equation maybe written as
tan(5 theta ) = tan (pi/2 - 2 theta)
but why
so that's entirely different, they are saying cot(2 theta) = tan(pi/2 - 2theta)
and this is true because sin(x) = cos(pi/2 - x) and also cos(x) = sin(pi/2 - x)
since cot2x = tan(pi/2 - 2x) and tan5x = cot2x that is why tan5x = tan(pi/2 - 2x) right?
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to solve sin(9 theta )= sin( theta)
i can write sin (9 theta)= cos(pi/2 - theta) but due to this i am unable to compare angles
what other way i should do
$\sin^9(\theta) = \sin(\theta)$
Alexis_Fx
this?
$\sin(9\theta) = \sin(\theta)$
Alexis_Fx
yes
huh
.
add $
oops mb, thanks
i don't get it
sin(9x) = sinx
sin(x) = cos(pi/2 - x)
sin(9x) = cos(pi/2 - x)
sin A = sin B →
- A = B ± 2nπ ,or
- A = π-B ± 2nπ ,or
did you know that?
no
I should tell you an easy way to derive relation between A and B if sin A = sin B, cos A = cos B, tan A = tan B
go ahead
For sin A = sin B
- Imagine an angle A in 1st quadrant.
- sin is +ve in 1st quadrant so what is the other quadrant in which sin is +ve? It's 2nd quadrant.
- In the second quadrant, make angle A from the x-axis(which in this case will be from negative x-axis) and then measure that angle from +ve x axis and you get that that angle is π-A and that's B.
- Sin of any angle is equal to sin of ±2nπ that angle so our relation is "sinA=sinB" implies either
- A=B → A=B±2nπ
- A=π-B → A=π-B±2nπ
try to draw unit circle and visualise it. It's really simple way
yes doing
can you tell me a way to write values for angle for different trigonometric equations when required?
because i have to look every single time to unit circle again and again
isn't there a way to do it wihtout looking at it again-n-again
there are different formulas for each and they look ugly, I can write them for you but for real, if you do some practice with this, you can derive them from unit circle in your mind
i do this but sometimes i get wrong
sinA=sinB → A = nπ + (-1)^n B
cosA=cosB → A = -B + 2nπ or A=B
tanA=tanB → A = B + nπ
for that question the answer is theta = npi/9 +(-1)^n theta/9
that is what you get from here
i applied that 1st relation
you need to derive it for sin, cos, tan and I think it's pretty ez once you get it
yes that's correct
answer in book is npi/4 or (2n+1)pi/10
9x = nπ+(-1)^n x
9x - (-1)^n x = nπ
x (9-(-1)^n) = nπ
x = nπ/(9-(-1)^n)
oh
so it basically broke the solution for even and odd n
this gives a single solution
the book gave 2 solutions
if i get anyone of from the book then thats also fine
for even n,
x = nπ/(9-1) = nπ/8
for odd n,
x = nπ/(9+1) = nπ/10
notice you can write even n as n=2k and odd as n=2k+1
x = 2kπ/8 = kπ/4
x = (2k+1)π/10
so yes both are correct
what are you assuming x to be?
again if you did it this way you would have gotten
9x = x±2nπ
8x = ±2nπ
x = ±2nπ/8
x = ±nπ/4
well if you consider n as any integer instead of natural number, you can just write it as
x = nπ/4
or
9x = π-x±2nπ
10x = π±2nπ
x = (1±2n)π/10
again notice if you have n as integer you can write it as
x = (2n+1)π/10
x is theta
you see that (-1)^n formula doesn't give intuition to what angles we are referring to that's why everyone uses this unit circle way. And you are supposed to simplify your answer like this so the reader and you can visualise what angles are being referred
i agreed this article with reason till point 3. but when i read point 4 i am just agreeing it without understanding reason
reason isn't clear to me for 4th point
so i can't understand
for 4th, imagine an angle in unit circle, now image that angle + 2π, what do you get? what does adding 2π mean? it means rotating the ray by 360 degrees
and you come back at the initial position
after adding 2π
now what's sin of the that? it's same as sin of theta
you see?
that's why adding or subtracting 2π to the angle doesn't change it's sin, cos, tan
yes as it comes to initial position on adding 2pi
you can add or subtract 2π any number of times so you write it in general as ±2nπ for n any positive integer but you can write it even better as +2nπ where n is any integer
😄
try to find relation btw A and B for
- cos A = cos B
- tan A = tan B and see if you can do it or not
interesting property
that's why you must know to visualise unit circle for trigonometry, it's very useful
btw it is true that if you add or subtract any say (2npi or npi or pi/2) it get's back to its initial position
no
only 2nπ
π means half rotation
pi/4 means one fourth rotation
why say for any anlge A if i add npi and subtract npi what is the difference
like this
are you taking 2npi for sin because x axis has values of 2npi
±2nπ is true for any trig function
for cos A = cosB
it is positive in both 1st and 4th quadrant by convention
A = B +- 2npi
for cos A = cos B
- A = B or better A = B + 2nπ
- A = 2π-B or better A=2π-B + 2nπ = 2π(n+1)-B = 2nπ-B
because you measure angles counter clockwise from positive x axis
for tan A = tan B
- A = B or A = B +2npi
- A = B + 2pi or B - 2pi
A = B +- 2npi
yes that thing was correct that since theta is positive in 4th quadrant that's why we make this diagram and get sin theta = sin 2nπ-theta
no 2nd one is same as 1st
- should be A = B ± π
beacause it reamins positive if jumping the angle from 1st to 3rd quad?
and that is difference of pi angle
right?
yes
3x = npi +(-1)^n 2x
3x-(-1)^n 2x = npi
x (3-(-1)^n 2) = npi
when n = odd
x(5) = npi
x = npi/5
when = even
x(1) = npi
x = npi
when even looks wrong,
3-(-1)^n 2 = 3-2 = 1
i am gonna do with inutitive method
now you got
x = nπ/5 (for odd n)
x = nπ (for even n)
But in your answersheet ALWAYS the answer is given assuming n is any integer. So you should write your answers in such a way that you don't need to specify n is even or odd instead just that n is an integer for which for even n write let n=2k since n is even and for odd n, n=2k+1
and get x = (2k+1)π/5 or 2kπ
where k is any integer
you understand this?
yes
in this method, you don't need to make cases for even, odd n as it's assumed from start that n is any integer so you get ez solution
that's why i prefer that way
then for this method i will do 3x = 2x +-2npi
x = +- 2npi
x = +- 2kpi
x = +- (2k+1)pi
this is not even rocket science why i am not understanding it
aah you just did that wrong
sin3x = sin2x
3x = 2x ±2nπ
i said you don't need to make even, odd cases in this method
wait let me
x = ±2nπ where n is an integer
you are almost there. Notice that if n is integer that means n itself can be positive or negative so there's no meaning in putting ± in front so you can write x = 2nπ where n is an integer
x = 2nπ where n is an integer
I know I made that mistake earlier, I should have written it as +2nπ Instead of ±2nπ
good
and the other one?
x = 4nπ?
show steps
x = 2nπ + 2nπ
yes
beacuse 3x and 2x are supplementry angles on unit circle and adding 2npi doen't effect
you need to write like this in exam
sin 3x = sin 2x → 3x=2x+2nπ or 3x=(π-2x)+2nπ for some integer n.
3x=2x+2nπ → x=2nπ
3x=(π-2x)+2nπ → 5x=(2n+1)π → x=(2n+1)π/5
No
bruh Not because they are supplementary because sin of theta and sin of π-theta are same because sin is positive in 2nd quadrant and by drawing A angle from positive x axis and A angle from negative x axis in 1st and 2nd quadrant and writing the angle between the ray in 2nd quadrant and positive x axis as B we get A = π-B and adding +2nπ doesn't change angle
Because if you remember it as supplementary angles, you might apply this to cos, tan and mess up. Though not entirely wrong but remembering it from unit circle drawing is better than as supplementary angles so you don't mess up in cos, tan
Is your doubt cleared?
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I need a help with this sequence problem.
a_n + a_{n+1} = 2x3^n, a_1 =1
I need to find the general term...
you mean, find an expression for a_n that doesn't involve previous terms?
What level are you? There are explicit formulas for this stuff
It's pretty similar to a 1rst degree differential equation
Have you learned this method?
you can try writing out a few terms (don't simplify).
a_2=2x3-1
a_3=2x3^2-a_2=2x3^2-2x3+1
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hi
!da2a
No need to ask “Can I ask…?” or “Does anyone know about…?”—it’s faster for everyone if you just ask your question! See https://dontasktoask.com/
Also, don't greet someone in help channel
Again, just post the problem. Don't do chit-chat
okay
xD
!status
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
Yes
i have more questions
Note that
$(\sqrt{a} + \sqrt{b})(\sqrt{a} - \sqrt{b}) = a-b$
this is part one
Xwtek
The important property for this problem. I don't know the name, though.
and i will see if I udnerstand
1/root 1 + root 2 x roo1 + root 2/ roo1 + root 2
Thats what the teacher said
I think
idk
@eternal osprey
actually wait
I opened a forum
but it glitched
I will go there
u can close this one
Okay, then.
I close it according to Aden's request, the owner of this help channel,
.close
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xD
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what did I do wrong here
you didn't evaluate y' at the specified point
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how to solve this
Re = real part; Im = Imaginary part?
yep
are you being helped
is this how undergrad math looks like ?
ive done this and im stuck
wdym
im in first semester
nvm
good that's. a great start
one moment...
yeah ok
$\Im(x+jy) = y$ and not $jy$ btw.
Ann
oh
also z^2 = a^2 - b^2 + 2abj; z^2 means z * z and not z times its own conj
i see the issue noe thanks ann\
so you should've had:
a^2 - b^2 + j(2a-b) + 3 = 0
yup
and then match real and imag parts separately on this. get two equations in a and b
this is assuming i didnt miss anything else.
i wanna ask smtn
yup as ann said
^^^
in the notation you wrote it'll take me a minute to tex the eqn
but you wont need it
^
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so is it like this?
perfecrto
regarding this only
regarding this question?
yes
ok then ask
.
i dont think we should be splitting hairs about the exact number of steps that this takes.
give us the equations after separting the im an re parts
yea nvm
who cares if it takes 5, 6 or 27.4493 steps.
nope
o
let OP work thru it and show us what she gets.
they're be conjugate sols
nvrmind
conjugate means you flip only the imaginary part
i used conjugate wrongly
im getting -1-2j
idek half of the words so its fine ig lol
okay so b = 2a
now if you sub that to - b^2 + a^2 +3 =0
you get a eqn ya can solve
you have the perfectly right idea
and you're doing amazing btw

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thanks :)
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Im trying to solve for stationary point of
does this even have a stationary point
can u show the full context
think about that
well there u go
well we certainly did part a right
your derivative is correct and your equation is correct
what about part b
now that you're staring at the equation e^x = -1
tell us: can this ever happen at all and if so for which x
my prof said e^x does not have a stationary point but I didnt understand why
what is a stationary point?
when the curve isnt increasing or decreasing
what does that mean mathematically
okay
when is the derivative of e^x equal to 0?
-# first question is what is the derivative of e^x
derivative of e^x is e^x
e^x is basically an exponential
x could be 2,5, 8, etc
e^8 is an exponential
okay
now when is e^x = 0
-# if you dont know what to do, draw y = e^x and draw y = 0 and look at where they intersect
y is an asymptode
y=0
as x aproches - infinity, it approaches 0 but never equal to 0
and now you said it
e^x is never equal to 0.
in fact e^x is always positive. its graph is always above the y-axis. (these are two ways of saying the same thing)
capisce?
ya unforunately you cant plug -infinity into e^x
the domain of e^x doesn't include -infinity
Actually e^x=-1 is a condition for being a stationery point. So not even asymptotically
and then etc etc look at what ann wrote
if u put a really small number or a big number, its good enough to be equivalent
no its not
if you put in a very negative number
e^very negative number = something bigger than 0
we need it exactly equal to 0 for it to be stationary
$-\infty$ is not in $\bb{R}$
-∞ is not in ℝ
Ann
do u meant above x axis?
yes sorry. typo on my part.
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Can the solution to a complex problem be a line like z = x + i (4x-5)/3? (4 + 3i)z + (4 − 3i)z (with a line above it) = 10. This was the original question
z(x) = x + i (4x-5)/3
this is a valid complex function
so, if x is unknown, then yes this is reported as a solution
Can the solution to a complex problem be a line like $z = x + \frac{i(4x-5)}{3}?$\
$(4 + 3i)z + (4-3i)\bar z = 10$\
This was the original question
This is sad 😢
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,rccw
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
do you know any trig identities that could help us here
Identity or value?
identify
identity.
No no I can't use value
In my syllabus I only have 3
What is sin(2A)?
show these 3
What does 🇹 emoji mean?
knight said identify instead of identity
knight _f3 misspelled the word
oops
oh
Sin²+cos²=1
Sec²-tan²=1
Cosec²-cot²=1
that's it?
Those aren't it
then you don't have the right tools.
it is unavoidable to work with either the identity for sin(A+B) or for sin(2A).
it is impossible to proceed otherwise.
Unless you derive them yourself 
BTW it is from mcq
I can put the value
show the options?
From all options
0, 30, 45, 60
Ik the answer is 0
But still I wanna solve it
then your only option is to check every single one of these lol
you dont have the tools to solve it properly
(yet)
That motherfucker textbook is telling me to justify
show full photo of page.
where do you see that it says to justify
Wait I have to click again
(iii) has "justify" nowhere...
btw learn to rotate pictures on your phone before uploading
Justify by testing each value
it is infuriatingly vague what the fuck it wants as "justification".
sin(2*0) = 0
Ais it NCERT?
Yeah!
Yup! I know I already putted it
Test the others and you're done
You've justified them
then you have the identity which was used in it..
Testing case by case is perfectly fine, you don't have to solve it generally
That's a point
Thanks
<@&268886789983436800> eye cue moratorium bypass
What
The testbook isn't mf, you are unable to do it
it's.... it's fine
Bruh
What? Are you complaining?
-# yay hayley is handling stuff for me 
technically I'll delete it since that word isn't allowed on this server but yeah it's fine
that's why i pinged, thank you
Why is it not allowed
Can I ask why it was offensive?
I just read #rules
Apperently you can't discuss intelligence or eugenics under any circumstances
So yeah
Oh! Jeez she is so strict
.close
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yooo
yoooo
How can we help you today?
Alright
Yes
Well the answer is certainly wrong cuz it's in terms of x and not z
it should be
the ans to 1 has many typos yes
quite confusing honestly
log5 x^2 + y^1/2?
is that log_5(x^2+y^1/2)?
yes
If so, that's wrong, as in general (\log_b(a)+\log_b(c)\neq\log_b(a+c))
PajamaMamaLlama
we cannot give answers, but instead us the log property (\log_b(a)+\log_b(c)=\log_b(ac))
PajamaMamaLlama
oke thanks
@terse adder Has your question been resolved?
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Ok so assume O is the center of the circle
Problem 12 (5 marks). 23 people are selected at random. Find the probability that at least 2 of them
share a birthday (day and month).
OA needs to be orthogonal to the left vertex
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Same for OB
Please stick to your own channel
Do you see where this is going ?
so like this?
Yeah give the edges names to make it easy
the sides of the triangle?
hmmm
is it ok to assume that the chord bisects the 90 deg tangent angle equally?
wait
this is an isoceles trapezoid so angle D and C are equal right? @wintry oxide
does that change anything from here?
Hmmm
(im not very familiar with all geometric theorems soo) ToT
I’ll keep thinking about it. I’m sure there’s a way I just don’t want to brute force it. Let’s keep this open for a while ok ?
alright alright
ill try to think
@wintry oxide I think my professor messed up
i found the exact same problem online, but it has 1 more thing given
yeah ill just clarify this to my prof 😭
Hmm ok ok
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Hello,
I would like help
!da2a
No need to ask “Can I ask…?” or “Does anyone know about…?”—it’s faster for everyone if you just ask your question! See https://dontasktoask.com/
ask away
@uncut sorrel Has your question been resolved?
💀
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Hiiii
anyone knows something about LightGCN ?
My goal is to build a recomendation system using LightGCN
but my question is how the model "learns"
i think i know how to make the predictions, i am currently working with 2 layers
But from my understanding hi^(0) , which is a vector of the user/book i, in the layer 0 should be the feature vector
my english is not that great so i hope you can understand me
You feed data?
and from then the model is completly deterministic
If it's deterministic, then you do have labels. Use them with datas.
is this an ai model or what
I dont really know, this is my first project working with ML ( Graph neural networks in this case )
if it is i suggest you go to computer science server
Are you familiar with ML knowledge, or did you just dive into Pytorch?
not much i would say
from ML i only know basic things
like Logistic Regresssion , One vs Rest ( i am having a course on that ( i am on the beginning ) )
SVM
also i learned in other courses LDA, linear regression etc
You know the part where models are trained using data, right?
but this is one course in which i have to make a research in this case it is this topic GNN aplied to system of recomendation
Loss function ?
No. How models are trained is that they are fed data.
You need data to train model.
That's how they learn.
Ahhh ok yes! i see yes! But when i give the model the data the process is completly deterministic, shouldnt be a part where my model updates coeficients ( like logreg for example ) and tris to minimize some function ?
Are you familiar with the pipeline?
Then you should probably take a step back and grasp the basic first. A model learns by data and the pipeline are probably the things you're introduced at the beginning.
So do you.
@exotic token Has your question been resolved?
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For this proof is there anything wrong with just saying through additive and scalar multiplicative closure?
u will indeed use closure but do u understand what u r being asked here?
this is precisely the equivalence of span defined through linear combinations and span defined through the intersection of all subspaces of V that contain the subset
u would wanna use a double inclusion to show that intersection of all subspaces containing the subset of V = all linear combinations of that subset
@merry crystal why is it not seficient to show something like this:
Through scaler multiplicative closure, each $\lambda _jv_j$ is in each subspace containing $v_j$. With additive closure, the sum of all such $\lambda _jv_j$ must also be in each subspace containing $v_i,...,v_n$. thus, this must be in the intersection as scaler multiplicative and additive closure says the linear combination of $v_i,...,v_n$ is in every subspace containing $v_i,...,v_n$.
BOSS
that's just half of the story if anything
ok you've shown the set of all lin combos is inside the intersection
that doesn't show equality
@gilded summit
wdym
we just have to show the linear combinations are in every vector containing v_1,...,v_n right
as dj said
you need the inclusion the other way also
intersection is inside the set of all lin combos
that's the other half
Im lost, why is that needed?
cause the question asks you to show set/vector space equality
the "is" in the question specifies equality
oh
show that [some set] is [another set]
yeah i get what you mean
its not asking if its in the interection its saying it is the intersection
yea
@gilded summit Has your question been resolved?
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I need help we just started learning force and motion so I need to know everything to solve this problem
watch this:https://www.youtube.com/watch?v=6dG5ScVtllQ or this:https://www.youtube.com/watch?v=_DD3zh0_L0M or both
In this video, the classic experiment with a cart, pulley, and hanging mass are being analyzed. This is a 2-part video. The first part focuses on how to analyze the forces, develop equations, and then solve for the acceleration and force of tension. The second part is where someone would find the acceleration (or have it given) experimentally...
Visit http://ilectureonline.com for more math and science lectures!
This lecture will cover Newton's Second Law: F = ma.
Problem Text:
A 5kg mass is placed on a frictionless incline making an angle of 30 degrees with the horizontal. A rope is attached and positioned over a pulley at the top of the incline. A 6kg mass is suspended from the ...
or wait indefinetly for someone to come
okay ill be watching
@nimble python Has your question been resolved?
basically just draw the free body diagrams for each of the objects, the only important thing to solve this is realizing that tension is the same for both objects
calculating x and y components of the net forces of each object + using F =ma solves rest of it
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Well what does Newton's law of cooling tell you
rate of loss of heat is directly proportional to temperature difference bw surrounding and body
@flat locust Has your question been resolved?
@flat locust Has your question been resolved?
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i need help with this question
i have
construct the radii
you have like a diamond shape or like two triangles
Good
Now what's the property of tangents
the radius is perpendicular to it
youll need to know value of tan 27 for this
Well it asks for the value up to decimal places
So I'm guessing calculators are allowed
can i assume that its 27 27?
Cuz if not I don't think there is a way to solve this
The angles are 27 each yes
how would you know that
It's a property of the line joining the center to the point the tangents are drawn from
But also you can prove it using congruent triangles
^
Anyway are you allowed to use calculators
yeah probably
In that case yeah find the sides of your right triangle
You know one of them is 17
And the angle is 27
i did tan 27 x 17 i got 8.7
but i thought the height was 7.7
oh shi nvm
no way i did that forget that😭
Good that's the radius
wait how
o/a
but are you sure the angle is 27 because when i did inverse sin(7.7/17) i got 26.93
and not 27
did you take the exact value of tan 27 to get the answer
yeah i used my calculator
here you can round it off
because the more decimal places you take the closer you get
alright so can you help me get p please im stuck icl
what step you on
like what all youve obtained
i got the height of the triangle is 7.7
could i use cosine rule 1 to get the radius
nope
...yes you got that from the tan formula
tan 27 is OA/AB
This is OA
Actually I got class, gonna leave this to you euh
use distance formula to find OA
alright
^
center of the circle is the origin O
its coordinates are (0,0)
so equate the value of OA you got with the distance formula
to find p
coooll
yo thank you
got it?
yeah
kind of bad calculations tho
you will need a calculator
or log table if yk what that is
bro idk why i didnt realize it was a right angle triangle from the perpendicular lines
i thought i was working with a non right angle triangle😭
lol
and then i realize when you were talking about it
radius is perpendicular to a tangent
yeah i knew that idk why when i drew my triangles i never put the right angle
so what ans did you get?
sorry for wasting your time😭
4
nah np lol
you rounded it off?
it was 3.96 it asked to one dp
you gotta round up tho
np
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${\alpha, \propto}$
k
also apparently c vs. C??
yeah i know i was so confused
no idea if those are meant as the same or different...
same
i dont understand how i connect these two
Alberto Z.
@haughty copper Has your question been resolved?
,tex You have $C = \alpha_1 B^{1/3}$ and $A = \alpha_2 C^{-1/2}$ for constants $\alpha_1$, $\alpha_2$ so what is the obvious thing to do
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Hello , I am currently taking Logic in college and we are dealing with syntactic and semantic consequences and so on which includes inferences rules , i want to understand whether those inference rules can be proven from a set of axioms (for example hilbert style axioms) + a single inference rule (for example modus ponens) or they are given by definition to just work in a logical proof system ? in case they all can be proven to hold true (which is something i didn't manage to do) please refer to any resource that deals with such topic , thank you
rules of inference and axioms are pretty much the same
the only real difference is that axioms don't work on antecedents
but that's just a function of how you choose to write them, for example
you can write
a, b |- a and b
or you can write
|- a=>(b=>(a and b))
it doesnt really matter that much
let me look up if these terms mean something specific in model theory so I can make sure im giving you a correct answer, one moment
okay so
here's what I found
rules of inference are defined as true, not proven true
