#help-28
1 messages · Page 124 of 1
hayley
in particular the power rule and the change of base rule will be very helpful here
get everything into base 2 or 3
yeah
yes
yes the divisor is 2
i need help about the uhh
use the power rule up top
dividend
wait
idk next step
does that makes ²log 4
and where do the superscripts goes
or exponent idk what its called
i don't think that 3/2 makes sense there
usually they're subscripts so I'm having a hard time following
at any rate, remember that √x = x^1/2
Ohh i see
and 4 is 2²
NOO its so weird
idk how to ask it
letme write it again then
log2 (root (3))^2 + log(root (3) (2)^2
or
log2 (3) + log(3^(1/2)) (2)^2
sorry idk how to use texlit
those are equal
yeah but which one is better
um the bottom one seems better
kk
uhh
it does not matter which one
idk how to do that
hayley
let me try
once everything is in the same base you can stop writing the base it's really useful
wdym
$\log_{(3³)} 3²$ will be $\f{\log 3²}{\log 3³}$ yes
hayley
what abt the base
kk
ohh a sec
the logarithm multiplication rule
i still dont understand this part sry
can i use this for something idkk
i guess you could
but literally just convert everything into log3
and then a lot of stuff cancels
it's unclear to me where you're starting from on that first equation
im turning them into log 3
oh. then no, that's entirely wrong.
draw a big ass fraction bar and put 2 below it
and nothing else
then focus on the nimerator
you'll have subfractions
it'll look like this...
the more you do this the faster you get, but you must do it correctly
should i just make it 2log3 (3) or just 2
if you're comfortable doing that in one step you can do that
do what
again, √3 is 3^½
log3 (2)
yeah
sure seems fine
and i dont know if its actually correct or no
and i havent even study exponent equation
it took me a dam hour
tysm
and the next one will take you significantly less time
uhh its currently 1am and i have exam at 7
i have some more subss to study
and next one is geometric and arithmetic sequence ugh which i need a lot of formula to remember
is this correct or wrong and or i can simplify it?
well
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looks right, idk if it can be meaningfully simplified
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,rotatw
,rotate
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What kind of function would generate a curve like this? I would've tried an exponential but it's almost like a reverse exponential, I'm confused
I'm not sure if I'm in the right place to ask so please point it out if I'm not, thanks <33
looks like a power law
if its something with like word counts or ranking, it would be expected
oh it does
amount of identifiers in relation to the character count
like x^(a) to be clear, with a clearly being some negative
Okayy I see
this is in the context of coding I assume? Are there other ways you can phrase this? what dataset are you looking at?
yeah it is in the context of coding
well idenfitiers and characters are like words of a language
because identifiers are just...variable names right?
and words of a language and their usage follow zipf's law/power law
it's just
y: unique identifier count divided by character count
x: character count
yeah, word lengths
Right i see
Zipf's law (, German: [ts͡ɪpf]) is an empirical law that often holds, approximately, when a list of measured values is sorted in decreasing order. It states that the value of the nth entry is inversely proportional to n.
The best known instance of Zipf's law applies to the frequency table of words in a text or corpus of natural language: It is ...
In linguistics, the brevity law (also called Zipf's law of abbreviation) is a linguistic law that qualitatively states that the more frequently a word is used, the shorter that word tends to be, and vice versa; the less frequently a word is used, the longer it tends to be. This is a statistical regularity that can be found in natural languages a...
this one
Not quite
yeah
it's the amount of unique words in relation to the size of the entire thing
OH
oh damn right on the money I think
maybe? or maybe I'm misunderstanding how you're ranking/assigning
Rank–size distribution is the distribution of size by rank, in decreasing order of size. For example, if a data set consists of items of sizes 5, 100, 5, and 8, the rank-size distribution is 100, 8, 5, 5 (ranks 1 through 4). This is also known as the rank–frequency distribution, when the source data are from a frequency distribution. These are p...
there's a lot of these, but they all tend to follow power laws
I think this is exactly it
thank youuu
i'm gonna go check it against the data
Yep
those two look pretty similar
Thanks a lott!!!
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would this be correct
based off of my notes it looks correct but it marked it as incorrect for some reason
nvm it was some stupid error I fixed it
thx
there was like a space in the answer box
Bruh webassign garbo
tru
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Find the number of times the digit $9$ appears in the list of all integers from $1$ to $500$. (The number $ 99 $, for example, is counted twice, because $9$ appears two times in it.)
龖
in 1-89 the digit ‘9’ appears 9 times
in 90-99 the digit ‘9’ appears 10 times
this can be extended for each multiple of 100 (up to 800)
so 19*5?
i would say so
what?
?
what would you say so?
the number 9 appears 19*5 times in all integers between 1-500
this is both answer giving and wrong
whats th ansewr then
I'm not giving you the answer
you can see what aysob did, the idea is right, then check it and apply the idea to get the right answer
bruh i dont see what he did wrong though
did you count both groups?
it's possible I'm the one making a mistake as well, in which case you should do what you know is right
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yeah i got 9 values for first
and 10 valjues for second
so dont you jst plus the two
so 19 values for 100 digits
and 19x5
u wrote 99 twice
doesnt the question say distinct though
OH
nvm
i loked at th wrong question
oh
so its 100
thanks
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"Sketch the solid by the given definition"
I can't think of a way I can math this out to make it make sense
I have half a cylinder right now
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Hi, im just learning sine/cosine graphing and my question is how can I get the starting point (reference point) from simply the equation. I know you can use (-h,k) but i was told at school by a friend that you cant always use h,k
This is the equation im trying to figure out right now, would the starting point be (-pi/6,-2) or am i wrong?
yeah that's right
if I understand what you mean by reference point
like the point on the graph that would normally be at the origin?
Yeah
yeah
is there any difference with cosine?
No, but the cosine graph wouldn't go through the reference point, right?
just to make sure I understand you
uhhhh cuz cosine is like min or max only right
yeah the normal cosine graph doesn't go through the origin, it starts at a maximum
does the question actually use the term reference point?
I just want to make sure we're talking about the same thing, becasue I don't think that's a standard term
,rotate
ok yeah it does seem to mean what I thought
so yes you have the right idea
I think what your friend was referring to, is if you have a coefficient in front of the variable, then you need to factor it out to find h
for example if you had cos(2x-pi/2)+1, you would factor out the 2 and make it cos(2(x-pi/4))+1
he was addressing this problem
ahhhh
nah we aint that far yet 😭
i got confused because i thought its always h,k when its in that form
these questions are from a team quiz we did a day ago and i dont remember exactly what we put since i just copied
wait, do you mean (h,k) as opposed to (-h,k)?
sorry -h,k
it is always the opposite of what appears in the function for h
Yeah
the only caveat is what I mentioned here
you tell me
😭 😭
no, you had the exact right idea from the beginning
just tell me what you think
exactly like the sine one
1sec let me graph it
wait im so confused
the "reference point" for the cosine graph doesnt exist unless i didnt graph right
,rotate
,rotate
lol
😂
graph looks good 👍
If I'm understanding what you mean by reference point, it's (pi/2, 1)
and yes, that's not actually on the curve for cosine
everything there is definitely right
but (pi/2, 1) doesnt exist
hm
you might need to ask your teacher to clarify what "reference point" means. I've never seen that term used like that and I can't find it online
yeah thats why i came here 😭
starting point is exchanged with reference point
previous page asked "What is the starting point (reference point)"
I'll ask around but I don't think it's common terminology
i just found some notes "reference point (h,k) - the new origin"
ah
okay, that's basically what I thought
then we shouldn't expect the graph of a cosine function to go through the reference point
the normal cosine graph doesn't pass through the origin, after all
Ah
and yes, it's (h,k), not (-h,k), but that's only because the - sign is in the general form of the equation: cos(x-h)+k
wait would it be that since sin graphs start at this "new origin" since they start at mid prehaps this reference point thing is just an artifical 0,0 or something
yes
artificial (0,0) is a good way to think of it
sin passes through the origin
cos does not
yeah cuz like u do x-h=0 and u move the h over which is x=h so u inverted the sign in other words
okay welp idk what that applies towards but thanks for ur help
🙏
sure thing 👍 no problem
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Alina wants to make keepsake boxes for her two best friends. She doesn't have a lot of money, so she wants to make each box described so that it holds as much as possible with a limited amount of material.
For Jen, Alina wants to make a box with a square base whose sides and base are made of wood and whose top is made of metal. The wood she wants to use costs 5 cents per square inch, while the material for the metal top costs 12 cents per square inch. What is the largest possible box (in terms of volume measured in cubic inches) that Alina can make for Jen if she only has $30.00 to spend on materials? (Round your answer to three decimal places.)
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#1(27)->#2(35)=29.6%
#2(35)->#3(48)=37.1% +7.5%
#2(7.5%)>#3(6.15%) -18% Delta
#3(48)->#4(63)=31.25% +6.15%
Scaling increases #4(6.15%)>#5(22.75%) +269.9% Delta
#4(63)->#5(97)=54% +22.75%
#5(97)->#6(~?)=
#6(~?)->#7(219)=
#5(97)->#7(219)=125.8%
I'm trying to find what #6 equals while factoring in the % scaling from the other numbers
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I am confused about how to compute low rank approximation
compute svd and then just ignore a few of the singular values
im going to leave this open i have more questions
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guys i need help with a geometry task it says: Imagine your math book is a rectangle. This rectangle stands on a corner and is held by the opposite corner. Your book rotates around the imaginary line (s. Fig.), which encloses a right angle with the table.
A) Draw an exact oblique image on white paper on a scale of 1:2. Enter all values and guidelines that have been measured or calculated (with a solution).
B) Calculate the volume and surface content of the resulting body.
For A I kind of know what to do but i’m stuck on B. The Book is 20x26,5cm and the rotation axis is 33.2cm. Now i don’t know how i’m supposed to calculate the volume and surface content 🥹
@languid lion Has your question been resolved?
nope
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is this a test?
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<@&268886789983436800> (not sure if this is actionable, but user deleted second screenshot that indicated this was a test)
i'll just time out for a few hours to make sure the test deadline passes
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Hello, I'm a chemistry student and i haven't officially taken MVC yet but i understand the basics. a variation of this statement with different variables is used for my lecture notes, and i am not understanding how this statement holds true. would it be possible for anyone to explain this verbally or write a step by step process to prove this? even a link to a page describing whatever law or rule this follows would be fine, i just don't know how to start.
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hiii
@lethal temple Has your question been resolved?
pls help
Do you see (5-9/2)²=(4-9/2)²?
yes
What do the numbers within each bracket evaluate to?
like, when you solve it what do you get?
Yes
it's 25-45+(81/4)=16-36+(81/4)
No no
Just tell me what the numbers inside the brackets evaluate to
Let the square remain
so (1/2)^2=(-1/2)^2?
it's 1/2=-1/2
Do u see the problem?
not actually
Ok can u gimme 5 mins
k
so technically i can't demonstrate them they're wrong?
No, they're wrong because when we take a square root, we have to account for both solutions
Sqrt(4), algebraically, gives 2 and -2
thx, really appreciate it
yes yes
thx
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"We can label the height and the slant height of the small triangle as H and L respectively. On the diagram below, h is divided in the ratio 2 : 1 (because "the strut is one third of the way up the ladder");"
similarity i suppose
but how
it tells that it is similar
but we don't know the length of the base of the other triangle
do u mind giving the full question
lol its given
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Can someone explain why this is true by the Markov Property: $P(X_3 = 3 | X_1 = 1) = P( X_2 = 3 | X_0 = 1)$.
I dont really see how the Markov property : future depends only on present works here
LeGM
Not enough context
given a transistion probability matrix for example and I am asked to find P(X_3 = 3 | X_1 = 1)
I want to know why this is true $P(X_3 = 3 | X_1 = 1) = P( X_2 = 3 | X_0 = 1)$
LeGM
is this just a time homogeneity property?
Yea that matrix is very important to the question
Notice the lack of indices less than t on the right side
Only the difference between t and t+n matters
Apply that to your problem
@stiff swan Has your question been resolved?
ok I got the answer 1/15 but what's the point of this $P(X_3 = 3 | X_1 = 1) = P( X_2 = 3 | X_0 = 1)$ equation
LeGM
is it just to clearly show how many n-steps are required?
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what's the question?
it wants x lenght
are you supposed to use trigonometry btw?
No u shouldnt for now
Maybe you should draw a diagram yourself, this one seems inaccurate
not sure how to continue without trig though
No, this question is correct, it's just very difficult to see, at least for you and me. And you shouldn't do it with trigonometry, because according to the topic order in the book, I haven't seen that topic yet.
Please anyone?
<@&286206848099549185>
Yep its 90 degree
Btw if anyone wonders this is a geometry question for YKS (Turkiye university exam)
I tried for a bit but the only way I can think of is finding the value of sin(15) with geometric arguments
You can look up how the exact value of sin(15) is derived
Here's a more accurate version of the drawing by the way:
Thank u for ur attention but i wonder is there no way to solve this question other than trigo?
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@olive horizon u here?
ig i solved it
forgot to write it, u get BH by doing pythagoras in BDH triangle
ig it's like this
we need to find x
from what i understand, you have proved that dbc=dcb=15degrees
but that could be proved by taking the angle sum property for triangle adb and dbc=dcb because they are base angle of isosceles
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i have no clue as to how to do this question
all i was able to find so far is that AEC=84
clearer version
<@&286206848099549185>
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Gordon Freeman, you can use pythagoras in the end for your answer. the value of tan 15 is 2- root 3
in terms of x?
IMz
not much info cuz of the question
aint being full
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so i find r'(t) = <2t,5,3t^2>
ah wait i need to find the unit tangent vector right?
the unit tangent vector looking realllll weird here
@outer dust Has your question been resolved?
hi keaton!!
hi
you don't need to actually
converting to parametric form, the line has direction vector (-2, 5, 3)
so you just need to dot r'(t) with (-2, 5, 3) and set it equal to 0
the value of t you get will give you the point
i tried that but i just got 9t^2-4t+25=0?
yeah
that cant be factored, oh do i need to use the quadratic formula?
huh
oh wait the normal plane of the curve
ahhhh so when (t^2, 5t, t^3) is some multiple of (-2, 5, 3)
cause the normal plane of the curve is perpendicular to the direction vector of the curve
so the curve and the direction vector are parallel
yea im not sure though how to proceed, its looking for a point but i cant stop thinking about cross product
which i know is wrong
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for this problem you are trying to determine if the shapes are congruent. If they are what transformations are needed. My friends told me how the figures are not congruent as point N is odd whille all the other points are even. Can somewone explain this further please
i think what they mean by even and odd is that triangle ZXY's vertices are all on coordinate points, while triangle LMN has the point N that lands somewhere in between coordinates.
Meaning the y value of point N is odd right?
i wouldn't call it odd, we could say its y value is not an integer.
The cordinates of P N are (8,-5)
ah i wasn't reading the whole graph mb, yeah then what they said about even/odd is true.
the triangles are not congruent and thus cannot be mapped onto eachother.
What do the odds and evens represent
just points on the coordinate plane
you could also just find an angle or side that is not similar to the other triangle and prove they are not congruent that way
True
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I thought i was right
yea u are right.
hmm it didn't work tho
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thank you
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how do i approach this problem
i tried to simplify it
which gives me [abc + a + c]/[bc + 1] = 3.14
no idea how to go from that (or if its even right)
consider that since b,c are positive integers
b + 1/c > 1,
what will be the range of 1/(b+1/c)?
it would still be greater than 1 right
ℝαμΩℕωⅤ
OHHH
okay so
sry i thought since a>0 then 1/a>0 it also applied to a>1 😅 im dum
since 1/(b+1/c) is less than 1 and a is a positive integer
a = 3
and 1/(b+1/c) = 0.14 ?
b + 1/c = 7 and 1/7
so b = 7 and c = 7 ?
so a + b + c = 17
yeh
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Im trying to solve this problem and keep getting lost, here is my work:
A valid basis, but not unique - different ways to do it, luckily you know that each option is linearly independent by not being scalar multiples of each other, so you could test whether each vector is a valid element of the plane
so if the answer was a, i should be able to plug in x_1 = 1, x_2 = 2, x_3 = -1 and get 0?
hypothetically lol
Yep, that's the idea - do you get zero when you do that? similar for the other one (they're also nice to repeat the options a bit!)
ah
well tysm that makes it so much easier
was there anything wrong with my approach?
Not really - as mentioned, your basis is valid, so if they asked you for one, and you gave that, it would be fine
Another way you could do it is to see if you can get any of the other vectors from your basis ones
For example, $\pmqty{1 \ 0 \ 3} + \pmqty{0 \ 1 \ -2}$ is a pretty nice choice \catthink
@devout valley
just to make sure I understand, d would be the answer because you can reverse plug them back in?
Yep it's d 
Ok bet thank you 😄 ive been at this for so long lmao that explanation really helped
I kept thinking i did something wrong and not finding my mistake, didnt know there were multiple answes
answers*
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Also note that this gets you the $\pmqty{1 \ 1 \1}$, you can get that $\pmqty{1 \ 2 \ -1} = \pmqty{1 \ 0 \ 3} + 2 \pmqty{0 \ 1 \ -2}$, so from your basis you can create theirs
@devout valley
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✅
sorry was just trying to add that in 
wait so if I just factored mine a little I could get that too?
ah
well thats good to know lol
But yep, (uncountably) infinitely many in fact(!)
to build on that they have a couple more equations with the same style of questions
can I do the same thing here? like reverse plug them back in?
Basically for those ones, you want to figure out if the sets are linearly independent (for a set of two vectors, that's if they're not scalar multiples of each other) and they satisfy the equation 
Note the importance of the linear independence comment!
(one you should immediately be able to rule out as a basis from just looking at it...)
so both the vectors cant be a multiple of other ones? Like for ii they arnt liniarly independednt?
sorry I came from diff eq lol this is my first lesson on linalg
Yep, (ii) is linearly dependent, in fact any set with the zero vector in it is linearly dependent!
hmm ok thats neat
so for these, as long as they are not linearly independent and they satisfy the equation they work, no more rules?
and I can do what i was doing before to find it if ans choices are not given?
For this one, pretty much (might change a bit for other questions though!)
Yep, you can!
ah ok perfect, so for this one the last two work
second one isnt liniarly independent
and first one jsut doesnt satisfy the equation
nice nice!
ok bet
again tysm lol you just explained something to me which 30 minutes in the book did not
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How do I simplify $\frac{1}{\frac{x+2}{3x-6}}$
Matt
kcf
?
keep change flip
when u take the reciprocal of any fraction
it just makes the denominator the numerator
1/(x+2/3x-6)
ohh
is the same thing as 1 * (3x-6/x+2)
then factor the numerator
and u will see it simplifies nicely
ur final answer is
just
so $\frac{3x-6}{x+2}*1 = \frac{1}{\frac{x+2}{3x-6}}$
Matt
$\frac{3(x-2)}{x+2}$
Matt
👍🏻
i see
yup
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no problem
factorisation not needed
why
doesn't make it objectively simpler
its situational
here there's no significant difference
true
so not much point
🤷🏼♂️
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I need some help understanding this conclusion.
jan Niku
We have some function $\rho(t) = \phi(t) + i \psi (t)$ is analytic. Assume we are moving along some contour $C$ where $\psi$ is constant, and that $\phi$ has a maximum at some $t_0$ on the interior of $C$.
Now, what Strogatz says is that let $\hat T$ be the unit tangent vector at $t_0$. Then the directional derivative $\dv{\psi}{s} = 0$ at $t_0$ since $\psi$ is constant on $C$ (here $s$ parameterizes $C$). But, $\phi$ satisfies $\dv{\phi}{s}$ at $t=t_0$ because $\phi$ has an interior maximum there. so $\dv s (\phi + i \psi) = 0$ at $t=t_0$, and $\dv s \rho$ in direction $\hat T$. But $\rho$ is analytic, so its derivative is the same in all directions. Then $\rho ' (t_0) = 0$, and $t_0$ is a saddle point.
I'm not sure that i understand why t_0 is a saddle point
the fact that both the directional derivatives are 0 along C at some point would mean that both phi and psi should increase if we moved orthogonally off of it there, right?
I get that this means that the level curves have crossed, I just dont understand what that means for the global curvature there
why cant we just have a maximum or a minimum?
@plush egret Has your question been resolved?
@plush egret Has your question been resolved?
@plush egret Has your question been resolved?
@plush egret by interior of C, do you mean a point not on the endpoint? or do you mean that C is a closed loop and you're talking about the area bounded by C
i think you were talking about the former. let me see if i can explain
C is just some counter along which we have $\psi$ is constant
jan Niku
I just dont think i undestand some kind of critical relationship between the directional derivative, the level curves, the gradients, the function, and the CR equations 
my thinking is that by CR you immediately have that p'(t) = 0 implies a saddle point
phi_x = psi_y, and phi_y = -psi_x
if you were to have a maximum, you would need phi_y = psi_x as well
i guess i dont believe p'=0
i mean, i dont really get why we have that
strogatz just constructs it
out of p=phi + ipsi
but i am not convinced thats uhh
i am not convinced
like its a dot product ... does that give us that we can just assemble it this way?
p'(t_0) = 0 by construction
phi' = 0 on C, and psi' = 0 by virtue of being a maximum
or
i have it backwards
but yeah
i guess okay maybe by stretch of me saying i understand and believe
direction derivative along C of p is 0
but why does that give p'(t_0) = 0?
i guess critically at t_0 in the direction of C
what does p'(t_0) mean to you
im not really sure 
i have in my head either a minimum or a maximum of the function locally
and there it makes sense
i mean rigorously
i dont know
i understand it as p' = phi' + i*psi'
where (-)' = d-/dt
or ds
whatever the parametrization variable is
i guess we get interactions between phi and psi maybe cancel some of that dependence out
(\dv{\rho}{t} = \pdv{\rho}{x}\cdot\dv{x}{t} + \pdv{\rho}{y}\cdot\dv{y}{t})
maximo
where dx/dt and dy/dt are coming from the countour C
bleh i might not know enough multivar to understand this
well like
i think strogatz is trying to lean into multivar calculus
to be handwavey about complex stuff
the countour C can be parametrized via (r(t) = \langle x(t), y(t)\rangle)
maximo
sure
we then have the tangent vector (\langle x'(t), y'(t)\rangle)
maximo
oh
only makes sense while you're on C
then this almost looks like grad r dot tangent
yeah
but each component function has its own gradient
should i not be putting too much neccesity on understanding his like
construction of dp/ds?
youre talking about it like i can just jump to dp/ds at t_0 along C directly from just understanding how its constructed there
the point, i mean, not dp/ds
does that make sense 
what i am saying is that dp/ds only makes sense along C
if you forget about C
and forget it's parametrization wrt s
then dp/ds loses meaning
what is ds?
i understand that, i mean, then you don't have a tangent vector so what are you even dotting it with
yeah exactly
but strogatz moves right from dp/ds to p'
so idk if understanding how he builds up from the other directional derivatives is critical here
should it be clear why mechanically we can do that
idk anymore
i used to think of it as a linearization
but i dont think thats right either
i mean, i can give the definition
but i dont understand what it means on an intuitive level
maybe im jumping ahead of myself
have you shown that analytic implies smooth?
i heard ryc say this the other day
i dont really get what it means
doesnt analytic just mean its once differentiable?
in whatever blah domain
so this is saying if you can differentiate once, you get infinitely many as a result?
but i hadnt heard it until ryc said it
differentiable -> smooth on C is another result yeah. im actually not sure about the relationship
what i was going to say is that you know p is analytic
and so smooth
okay
so what you should expect is that the derivative at a point behaves well, regardless of where you approach the point from
this is just because you can break it apart right
i mean or maybe uhh
you arent restrained in your choice of what distance means in the limit defn of the derivative
wrt direction
or i guess you mean more intuitively otherwise itd indicate some kind of not niceness
a jump or something somewhere
but that wouldnt make sense
because its smooth
yeah what i think of is that our complex derivative exists, and so the limit converges "regardless of path"
so this contour is not particularly special when it comes to the derivative, that is, p' is going to be 0 regardless of which contour we approach x(t_0) + iy(t_0) by.
C just has some outstanding properties that let us compute the derivative
namely that psi is constant and phi has a maximum at t_0
so its like
if we find some path through the complex plane
and some tangent unit vector along that path gives dp/ds
then if p is analytic, it must be that p'(that point) = 0, too
i guess it didnt make sense to translate from like
derivative is notion of as you approach a point
and to me directional derivative is like
if dp/ds = 0 here, then yes i think we are saying the same thing
as you move away from it
so i think it doesnt seem like they should connect in that way
okay so
so why does p'(t_0) = 0 mean t_0 is a saddle point
should that be clear
you said something before, sorry
CR
this
phi_x = psi_y, and phi_y = -psi_x
i don't really get why this would mean saddle 😳
is it intepretable through gradients/level curves
let me see
maybe it's not as obvious as i thought
i was thinking that if phi_x = psi_y and phi_y = psi_x, that would amount to a max/min
so changing the sign in one of the directions would result in a saddle instead
i guess i dont even get why that would mean max 😅
let me see if i can justify it somehow
i was more wondering like
i just imagine, two level curves
each one is at level 0 or however you would say that
and theyre orthogonal
and the gradients are pointing some direction orthogonal to the level curves
so really, at t_0, you have gradients pointing along each level curve, like an overlayed capital L ontop of an X
yea i guess i dont know 
@simple totem I appreciate your help, my sleeping pills are kicking in
maybe itd be better if i slept on it then toyed with this and see what happens
i can come back with something better than idk

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yeah i was trying to think of something but nothing comes to mind
maybe i should look at the definition of a saddle point in C 😂
good night jan
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can someone explain what formula theyre using
@verbal adder Has your question been resolved?
<@&286206848099549185>
@verbal adder its the exponetial decay model f(t)=A*e^kt
Prove that (abc)^2>4∆/√3, where a, b and c are the sides of a triangle and ∆ is its area. Give me a hint
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tiny question about cauchy sequences and the right intuition
so the way i understand it cauchy sequences are those where the elements get arbitrarily close together
however, in my lecture notes it says that it is not sufficient to require that the distance between successive elements converges towards 0 and i have a hard time understanding why
Because cauchy says something stronger
not just about the difference between consecutive elements
But about the differences between every element
if that makes sense
I remember a question on a quiz or something from my analysis class that provided some intuition as to why exactly this is different
but its been a while so i cant remember
but if i think about it visually, the elements of a sequence whose consecutive elements get closer and closer, wouldn't that mean that if i go along infinitely long in the sequence all elements will converge towards 1 point
in the lecture script we got it just says that these notions are not equivalent but not why 😕
cauchy says for any value n and m greater than some N, we have |a_n - a_m| is less than a given epsilon.
What you have is that after some N, |a_n - a_(n+1)| is less than a given epsilon
take something like a_n = log(n)
as n increases log(n) and log(n+1) get closer. So at some point |log(n) - log(n+1)| will be less than a given epsilon.
however, log(n) and log(1000n) will always be far apart, so log(n) is not a cauchy sequence.
okay thank you both, i don't totally get the intuition but i see how the statements differ
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Hello guys, could someone help me with this?
I guess i'd have to use simon's favorite factoring trick here
Not sure how though maybe i'm dumb
x + y = 1/4 xy
yeah
notice that x+y is an integer
thus 1/4 xy is also an integer
so xy must have a multiple of 4
hmm okay i see
4x + 4y = xy
4x + 4y - xy = 0
x(4-y) + 4y = 0
x(4-y) -4(4-y) = 0
(4-y)(x-4) = 16
then list out all the combinations?
not sure what you did here
i rewrote it so that i can factor?
i subtracted by 16
so i added by 16 on the other side to compensate for it
oh whoops typo
yes since i'm subtracting 16 from both sides i add it back to both sides so rhs should've been 16 not 0
||dont want to disturb you guys,
i just have one idea to solve it,
according to the question we need to consider a line y=x and all the points above this line and on this line would be the points where x<y
so you might try sketching the graph or taking intersections maybe
might help ya||
i'm not sure what you mean 😭
it should be -16 right
or am i dumb 😭
(x-4)(4-y) = -16
(x-4)(y-4) = 16
not trying to be pedantic, just making sure 
never mind me
although i dont think it would work
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derivatives
$e^{5tanx} + 5^{2x}$
odokawa
why I can't to use the sum formula
are you trying to compute [
\m[\bigg]{\dv x}{e^{5\m\tan x} + 5^{2x}}
]
odokawa
yes that is valid (not the way you wrote it)
Use chain rule
chain rule for this?
5sec^2
What 💀
or am I wrong
i have mental issues and skill issues if you could help me to understand better it would be great
That is the chain rule
$e^x = e^x (x')$
odokawa
You are smart my dude, just missing out on a stupid theorem
Yes
That
$e^{5tanx} (5sec^2e^{5tanx})$
odokawa
this for the left side
Why would e^x appear again
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This has to be in cos
I don’t understand the period
so far I have this 5 cos ( x + pi/3 ) -2
<@&286206848099549185>
<@&286206848099549185>
Do you have problem finding period ??
yes
There's a property stating thar
If fundamental period of f(x) is T then fundamental period of f(ax ± b) is T/abs(a)
Just use that
can u simplify what u said cause i did not understand a single word
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Hello