#help-23
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I just don’t understand how it relates to the other problem cus this is how we did it in class but when I try to do it that way it did not work
Yes that's the easy way you can solve this.
You have $20e^{-0.0001216t}$ and you want to know when you'll have half of what you started with (20)$
Azyrashacorki
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So you can write $10 = 20e^{-0.0001216t}$ and solve for t.
Azyrashacorki
I try to solve it but I get stuck here
Then you can divide both sides by -0.0001216
570.02?
On the answer key it is 5700 years so idk what I did wrong
I double checked and I wrote down the original problem correctly
I’m just really confused I don’t know what I did wrong even with the answer key
Ohhh
That should give you the right answer now
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Hello , I need help with this problem please
Okay, so this is a standard optimization question in Calculus.
Yeah
What is your understanding of optimization. What do you think the first thing we should do here?
What are we trying to solve for?
We need to find our objective function and our constraint function
Right, so we our trying to find the largest Volume we can obtain, so quantity is volume and we are maximizing it.
Volume = LengthWidthh
Wdym
So what relations do we know to rewrite it in terms of one variable?
Shouldn’t it be f(w,h,l) = whl
We need to rewrite the volume in terms of one variable, so we can solve it and differentiate it.
it is, but we need to know rewrite this in one variable.
You can do that utilizing the other information you are given.
Why tho?
In similar problems I didn’t have to rewrite anything
Ohhh btw
Because what would you do if we didn’t rewrite it in terms of one variavle
I’m doing Lagrange multipliers
I can help you with question 6
lol
Optimization.
Yea
Okay so to rewrite it in terms of one variable.
The problem is I have a test ina few hours and I didn’t learn it this way and I’m tryna build off of my previous knowledge so I don’t get too confused also because I’m lowkey running out of time
So
Well then you need to know this as this is essential
Do you want me to give you the answer
you may learn better that way
I’m trying to do Lagrange multipliers
You already have the volume of the box as your objective function
Now you have to write down your constraint equation
Cost = 4sides + 1 top + 1 bottom
-> 4(lh)2 + (lw)2 + (lw)*3
15 = 8(lh) + 2lw + 3lw
Hmmm lagrange multipliers, I see its slightly different than optimization but same idea at end of day.
The dollars are confusing
It’s really a constraint on the surface area you’re given
So you need to find the cost of the box in terms of l, w and h and then your constraint says this cost is fixed at 15$
2(lw) + 3(lw) = 5?
Idek 😂
I mens
Mean*
Sketch out the box. You need the surface area of the top and sides along with the surface area of the bottom
I need to bike home I’ll be back in 20min
For sure take your time man
@honest idol Has your question been resolved?
Okay have you got a sketch?
Okay I feel it's hard to see what's going on with this. I was expecting more a 3d sketch
Now you need the surface area of the bottom, and the surface area of everything else
so when it comes to contraint formula, we want a formula that the volume cant exceed right?
so how are we doing that here
Don't overthink
Do you need to maximise the volume? Then, well, you have to write the volume formula, using some suitable variables
So with these names for the main dimensions, can you write down the volume formula?
V(h,l,w) = wlh
i have no idea tbh,
i didnt really give anything besides the volume formula
Say we disregard the fact that the cost must be 15$ for a second.
Can you write down what the area of the bottom side would be in terms of those variables ? What does this part cost then?
Can you write down what the surface area of the rest of the box is (without its bottom)? What does this part cost?
Can you write down what the area of the bottom side would be in terms of those variables ? What does this part cost then?
l*w
Can you write down what the surface area of the rest of the box is (without its bottom)? What does this part cost?
2(w x h) + 2(l x h) + l x w
idk about the cost part tbh
Oh there fixed
Okay.
They're telling you the bottom costs 3$ per unit area to make.
How much does the bottom cost?
3 dollars?
So the bottom has area 1?
You can assume w, h, l are given in cms, it doesn't matter.
Oh alright
2(wh) + 2(lh) + lw = 3
If I tell you the area of the bottom is 4 cm^2, how much does the bottom cost to make if it costs 3$ per cm^2?
12?
Right, so you multiply the area by the cost per unit area to get the cost.
wait so its 2(wh) + 2(lh) + lw = 12
The whole point of the setup is to express the total cost of the box in terms of w,h and l. You have no equation yet since the constraint is specifically a constraint on the total cost of the box.
true
So I'll ask again. If the bottom of the box has area w*l and you're given that the bottom costs 3$ per unit area to make, what is the cost of the bottom of the box?
w*l = 3
No equations.
It's the same thing as here but with w*l instead of 12.
i know youre probably asking a trivial question but its not clicking for me rn idek why
The thing is you answered it with a fixed number.
For a bottom with area 4 cm^2, you said that the cost was 4 * 3 = 12$
For a bottom with area w*l cm^2, it's not a different process.
Good. So the bottom costs 3wl to make.
Now you need to compute the cost of the rest of the box.
You computed its area earlier
And you know it costs 2$ per cm^2.
so 2( 2(wh) + 2(lh) + lw )
Good. So the rest of the box costs 2(2wh + 2hl + wl) to make
What is the total cost of the box, then?
Yes, so you have your constraint given by 4wh + 4hl + 5wl = 15.
ohhhhhhh
the constraint equation is kinda confusing
is it not supposed to be expressed in the way im expressing it?
Why? 😅
because of the = 15
How's it troubling you?
You can (and should) bring the 15 to the left hand side
So that you have g = 0, where g is your constraint equation
ohhh
your constraint equation is always in the form g = c?
Note that I also what I wrote here... @honest idol
thats after differentiating it or what
No? I haven't even mentioned differentiation
i mean
yeah i think im confusing the = 0 part but thats just f(x,y) = z
such that z = 0
so its not really different from any funciton in space
Wait wait
well that was a bold claim
Whatever you get as your constraint, (expression)(x,y,z) = c, you can always rewrite it as g(x,y,z) = (expression)(x,y,z) - c = 0.
It's standard to do this.
Try (equation 1) - (equation 2).
bruh what am i doing
oh its a linear system 💀
i just realized
It's not
yeah youre right
the thing is every time we solve these its like we do something random every time
It's not random. You have to spot things that you can cancel.
were always allowed to combine functions right
You can rearrange and substitute. You can eliminate, like this
You can do whatever you would do to solve equations in general, there just isn't a cookie cutter way to do it like for linear equations.
From here you could've multiplied through by lambda l - 4
This would give you a nice relation between w and l
oh shoot
all this is cuz of the overthinking
test is in like 30 minutes so ill just lock on off of what i know
@quiet plume thank you very much for your help
i really appreciate it
@quiet plume one last thing tho you said we dont care about lamda in these problems right
We don't care about the particular value of lambda, no
It does have a meaning, but for the purposes of optimization it's not relevant.
so you wanna avoid making lamda substitutions? or is it just what lamda is that we dont care abt
No, you can still use it.
All I mean is you don't have to find its value
Like you do for x,y,z.
would you say using lamda over other varibales matters or does it just depend on the problem itself
It doesn't change anything.
You could solve for x,y and lambda and then get z from one of the equations
i see
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Hey there, I'm trying to prove that if a topological space X is compact and Hausdorff, then X is normal (T4). The professors hint was to recall the proof for compact subspaces of Hausdorff spaces being closed and applying twice (once for each closed set), which i included below, but I really don't see how to do it. I'd really appreciate a further hint or something to guide me in the right direction :)
(I know this is a fairly standard result in general topology and that proofs exist out there but I feel like I miss out on a big part of the learning process by just finding the proof online)
Let $K\subseteq X$ be compact, $X$ Hausdorff. Let $x \in X\setminus K$. $\forall y\in K$, by Hausdorffness, $\exists$ open $V_y \ni y, U_y \ni x$ s.t. $V_y \cap U_y = \emptyset$. Then ${V_y}{y\in K}$ is an open cover of $K$, hence $\exists$ finite subcover ${V{y_1}, ..., V_{y_k}}$. Then $U \coloneq \bigcap_{i=1}^k U_{y_i}$ is disjoint from $\bigcup_{i=1}^k V_{y_i} \supseteq K$, so $U\cap K =\emptyset$, i.e. $U \subseteq X\setminus K$, so $X\setminus K$ is open QED.
dan
@lone shuttle Has your question been resolved?
Take any two disjoint closed subsets A,B of X.
They're both compact as closed subsets of compact spaces are compact.
Iirc the idea is you can parameterize open covers of B in terms of each point of A using Hausdorfness (like in the proof you sent kinda) which also gives you an associated open cover of A. You should be able to get something nice if you tinker with those a bit.
thanks for your reply! I'm finding it pretty tricky to construct the necessary open cover but I think I get the general idea of how you need to do it now (by basically simultaneously constructing an open A and B cover from what I understand)
maybe I just need to approach the problem with a better rested brain, ive always found point space topology to be a difficult subject
Essentially, you should find a way to construct, for each element of A, an open neighbourhood of it and an open cover of B which doesn't intersect this open neighbourhood of A. Then you could string those along A and do more stuff to make sure everything is nice and disjoint.
But yes, rest helps a lot!
tysm! in which field of math are you studying if i may ask?
just curious
Hmm I’m doing masters atm but mostly differential geometry / algebraic topology type stuff
is there any diff geo textbooks you'd recommend? I'm taking a class on it this semester and my prof is so disorganized
I think the standard one is Do Carmo’s diff geometry of curves and surfaces
I think he explains relatively well and the first 3 or 4 chapters cover pretty much what one would see in a first course in differential geometry I reckon
There’s Ted Shifrin’s notes online as well which may provide outside perspective
I think I understand now, is the general idea to basically fix an element $x \in A$, and then for each $y\in B$, you get (similar to the proof above) some $U_y \ni x, V_y \ni y$ disjoint. You then get an open cover of B by ${V_y}{y\in B}$, you use compactness for a finite subcover ${V{y_1}, ..., V_{y_k}}$, then you set $\mathcal C\coloneq {U_{y_i} : 1\le i\le k_y}$, and repeat this $\forall x\in A$ to get a cover $\mathcal C \coloneq {U \in \mathcal{C}_X : x\in A}$, and you can then play around with it pretty easily to show its disjoint from B?
dan
Yes, that’s pretty much the main point of the proof.
alright perfect I think I can do that now! thank u so much I really appreciate your help :)
Of course
I'll make sure to take a look at them, we use Do Carmo in our class but I find that I often find myself wondering why things are defined the way they are or why any of the results matter which I find that Do Carmo misses a bit off
thanks again for the advice!!
Yes that is true I found that as well reading it. Again Shifrin is pretty good and I think videos from, say, the bright side of mathematics, explain more obscure stuff nicely
Happy learning!
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do you have an actual question?
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I need help with Excel, if anybody is familiar with the Goal Seek tool
B16 is my formula cell, F9 is my variable cell (y)
I don't know why it isn't solving for y, so if anyone has some insight, I'd appreciate it.
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Hi guys could someone help me please, I think this is a binomial question but i dont use the formula i use a table
is this the correct layout, as in did i split it correctly
@crude light Has your question been resolved?
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https://claude.ai/share/62f8dac0-2d52-4470-8bc4-99bf3f9a3e02 Can someone explain me this Errichto iterative method for Chinese remainder thoerem? I haven't dropped the link of the video as some people may not like to watch a video just to explain a concept therefore they can read the claude explanation using this given link.
Whole
Actually i am on starting, I am not able to understand the starting part
so i don't have any idea if i will be able to understand the rest or not
https://youtu.be/EHDEvFuYPRQ?si=BYPmHCVfJ-jkAtVY here is the video i am refering to
A simple method for Chinese Remainder Theorem (solving system of congruences), without any modular inverse. Here's my code for Advent of Code day 13 https://github.com/Errichto/youtube/blob/master/AOC-2020/13-search/shuttle2.cpp
0:00 Example 1
2:02 In General
2:56 LCM
4:05 Big Example
7:31 Extra Understanding
Subscribe for more educational vid...
o this not working
ye
ask 1 at a time
ok
type .close pls
done
Had linked wrong video, now corrected.
it's like you're at the bus stop, and you just look at buses, and there's 3 lines, one arrives every 4 minutes, then there's another that arrives every 6 minutes, and there's a 5 minute bus
and there's not enough space for all three to fit, so you really want to stay and see what they will do
3,5, 2 is when the next bus arrives
you jut trial and error to find how long to wait
until they all arrive at the same moment
Lemme read
it's not chinese remainder theorem, it's too different, but people don't have different names for these problems for some reasion
But that is finding us a value that will serve all equations of modular arithmetic, and that's what the purpose of Chinese remainder theorem is also
So it doesn't matter to me. If I am getting the answer
🙂
Ok
Alright
But how will I find that?
According to what i understand after watching some part of video
One by one you mean?
yeah
if there's 7 buses you do 7 sub steps, where you increase the step
it's bruteforce that gets faster and faster
wikipedia says you could optimize it if you change the order from big mod to small, that sounds right
Let,
x = a1 (mod m1)
x = a2 (mod m2)
x = a3 (mod m3)
Then,
x = m1 × k + a1
And also,
x = a2 × q + a2
Putting equation 1 into eq 2 -
m1 × k + a1 = a2 × q + a2
Hey wait, what am I doing? 💀
I think it is not what he is doing
In the video
Did I mixed up two idea? Maybe 🤔
Because I was studying diphontine equation as well
<@&268886789983436800>
Was gonna do it too
it would be clearer as python lol
from math import lcm
buses = (4,3),(6,5),(5,2)
time = 0
step = 1
for m, r in buses:
while time % m != r:
time += step
step = lcm(step, m)
that's all
I know C/C++ but not able to understand this code 🤔
By the way phone is about to die
Will be coming back in half an hour.
mod = [4,6,5]
remainder = [3,5,2]
time = 0
step = 1
for(i=0, i < 3, i++) {
while (time % mod[i] != remainder[i])
time += step
step = lcm(step, m)
}
more c less hiss
What is time and step variable?
integers?
Is buses a list?
What do u mean
What is this also 
it's python things, sorry for spamming the channel
I think we shouldn't jump into coding before I understand general maths
😅
The method in that video is not that complex
I just need someone who can explain me what he is doing
Basically
I can explain the part I understand
To see if I am right or wrong
@dapper grail Has your question been resolved?
that's not the correct ping, just for your information. you pinged a user.
Oh I am dumb 🥀
<@&286206848099549185>
I hope it's right now
that's the right ping.
@dapper grail Has your question been resolved?
Why is there no single helper to help me 
@dapper grail Has your question been resolved?
What do you want help with?
The question is above. Hidden in the Convo
Lemme tag
This
And this is the resources I am referring to
Okay do you understand how the modulo works at all
@dapper grail are you atleast familiar with Euclid's division lemma
No this
Modulo yes
Both are basically the same
So in the video the focus is to find the set of numbers that give certain reminders under the given modulos
So you should be familiar with the idea that if a = b (mod c) a can be b + nc where n is any whole number
Ah basically this is the algebraical form of the equation of modular arithmetic
So for say two modular equations a = b (mod c) and a = p (mod q) we just need to find the first nc+b for which we get p under mod q
Then to get the full set we need to keep on adding the least number that is 0 under mod c and mod q
Which is the LCM
Now if more equations are there repeat the steps where we need to find the least n(LCM) + the first nc+b (that is p under mod q)
The guy in the video just focuses on how the remainders appear to get the needed value then to find the number corresponding to it he multiplies the LCM with the number of remainders till the needed one (since you have to add the LCM that many times to get the wanted number)
Or you could just write down a bunch of linear equations and solve for them how ever you want
Lemme read
It's like -
Let,
x = a1 (mod m1)
x = a2 (mod m2)
x = a3 (mod m3)
Then,
x = m1 × k + a1
And also,
x = a2 × q + a2
Putting equation 1 into eq 2 -
m1 × k + a1 = a2 × q + a2
Then what do we do further?
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Question 59
I figured out sin and cos, and i tried to use sin/cos to find tan but I can’t figure out where I went wrong
(Sqrt(6)-sqrt(2))/(sqrt(6)+sqrt(2))
which exercise is this for
59
why do you think you're going wrong 
Well the equation i got after solving for tan is wrong
After solving this
ah
Multiplied the equation by the inverse of the denominator
yeah you're making a mistake while rationalizing
I got (6-sqrt(12)-sqrt(12)+2)/4
lmao
Does that simplify to 8-2sqrt(12)/4
yes
Then 4-sqrt(12)/2
yes
The answer in the key is 2-sqrt(3)
you can simplify this further
Oh you can?
yep
happens with the best of us 🙏
Thanks
np!
this one you can do in a lot of ways
what is this??
what's your first instinct seeing the big expression in cosx
Expand it
no!
Oh
your first instinct should be to take the terms common outside
ah
either way works
Yeah ig
after this do u see anything?
you're left with cos^2x(1-2cos^2x+cos^4x)sinx
the term in the bracket
any algebraic identity u remember?
you're not wrong here, its -cos2x btw, but that's not helping us in getting closer to something that looks like the RHS
2cos^2x-1=cos2x
hint: (a-b)^2
Its not coming back
wdym
I dont remember the identity
a^2-2ab+b^2
Wait hold on
I think you'll be able to see the next step
I dont see how its applied
Sorry its just not clicking
1-2*1*cos^2x+(cos^2x)^2
Now?
Oh alr that makes sense
But I dont think I could have seen that without this
you need to learn your algebraic identities fr
Yeah
there's another way
you begin with sin^5xcos^2x
and then you notice how the RHS has a lone sinx
so you take that out of sin^5xcos^2x
sinx(sin^4x*cos^2x)
now you see that
sin^4x=(sin^2x)^2
and from here you could do it
it's basically the opposite of what we did
yep
when u see sin^2x what identity come to mind
or u can see that in RHS
all the other terms are in cos
so how do u convert sin^2x in terms of cosx
I genuinely can’t think of how
Yeah
If there was like a 1-sin^2x i would get it
hmmmmmm
don't u think u can manipulate sin^2x+cos^2x=1 to get it that way?
this identity is true always
Well you subtract sin^2x to get it that way
yeah
What do i do with that
well you can also notice that you can subtract cos^2x instead
correct
Idk why that took me so long
it's okay
So then you got sinx((1-cos^2x)^2 * cos^2x)
1-2cos^2x+cos^4x
Times cos^2x is sinx(cos^2x-2cos^4x+cos^6x)
Yay
Thanks
np!!
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Guys can someone confirm if this is correct
<@&286206848099549185>
,w 300102 * pi /360
everythings correct!
Dont forget the units!!
@void locust Has your question been resolved?
Ty
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Your wlcm!
Have a nice day!!
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how do i find the range
If x=0 then the expression gives 3
Beyond that, the function is strictly decreasing
however it will never equal 0 or be a negative number
but it will be arbitrarily close to 0
You can show that in more mathematical detail if you're interested
but that's the intuition
but like why do we include 0 in the function to get 3 cuz like the x values RE GREATER than 0 so should we not plug in 1
That's an excellent question
The trouble is that 1 is already overshooting by a lot
because it would be better to start from 0.1, or 0.01, or 0.001, or 0.0001, or something like that
but if we play that game we'll always miss out on possible values
So it's a better idea to start from 0, then just exclude 3 from the range because x=0 is not actually allowed, and reason that anything slightly smaller than 3 must be doable
oh
As an exercise you can try showing that there is an x for which f(x)=2.99 even though there is no x for which f(x) = 3
In that case you can plug in x=1 to get 1
and this time you don't have to exclude it from the range
oh
then you can again reason that the function is strictly decreasing etc.
no worries ^^
sure
that works
alr bet
well done
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i am back with the work
,calc 1/sqrt(17)
Result:
0.24253562503633
il try and put all that in and see
you can try using more digits, it could be that
thx ive never had that issue before where it wanted more than 3 past dcml
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,calc 1/sqrt(5)
Result:
0.44721359549996
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yo guys,
if i wanna get the inflection points of an function and the 3rd derivate is equal to 0, that doesnt necessarily means its no inflection point but what do i do then
or what does it even means when its 0
If the third derivative is zero at a point where $f''(x)=0$, then the test is inconclusive. You'd have to keep checking higher order derivatives until you find the first one that is not zero.
\begin{itemize}
\item If the first non-zero derivative is of odd order, then you have an inflection point.
\item If the first non-zero derivative is of even order, then you do not have an inflection point.
\end{itemize}
(Note that this only works under the usual smoothness assumptions.) \
Honestly, you're better off just doing sign analysis on $f''$.
Civil Service Pigeon

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hello, i need help setting up the objection function and the constraint function
!show
Show your work, and if possible, explain where you are stuck.
@honest idol Has your question been resolved?
none
i dont know where to start
thats the issue
<@&286206848099549185>
yes i do
i understand how it works but not here
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✅ Original question: #help-23 message
Anytime you're given a fixed number for Lagrange multiplier problems, that's probably your constraint. Write down two equations for volume and surface area first
Waaaaarmaaaaaaan
i dont know how to set up the volume due to the fact that it doesnt have a lid
idk whats gonna be different here
yo
have we talked before
dude why am i lowkey known all over discord
Do you think if you take any face of a box the volume changes
no?
i wouldnt say so
Whatever assumptions you made in 4.7 apply here too
if then so whats the point of it having no lid i dont get it
Yes so what's the volume of a box
The surface area changes
how are you tracking my sections 😭
Second equation you should find
I read the question
"same problem from 4.7"
Do you need help doing this?
volume remains the same
like
uhh
imagine a cup
there is a certain volume of water that goes in it, will it matter how much water it can hold if it has a lid or not?
what matter are the dimensions
yes please
right
good point
now so the volume will be length x breadth x height = 4ft^2 like usual
whats confusing to me is the idea of how this can show us the gradient of the level curve and that of the objective curve
like
?
That has nothing to do with volume and surface area
just focus on your functions first
Maybe you should learn to focus on basics first
but isnt that the whole intuition behind lagrange multipliers
yes but our main goal is to find the functions to apply lagrange multipliers onto
No
Read the first two formulas and make sure you understand them before learning Lagrange multipliers
Only one part changes in the surface area for a box without a lid. Identify how it changes from the formula for TSA from the picture
yes
so
?
i have no idea dude
like im actually confused
theyre saying they want the least amount of cardboard possible
Have you never learned these formulas before
such that the entire volume = 4
yes i understand the fomrulas in and of themselves
but not in terms of
what we need to optimize
and what the constraint is
So write the formula for the surface area then
That's not enough
Volume formula is given here
Look at the picture again and figure out what l, w, and h stand for
length width and height
wlh = 4
Right. Do the same for surface area

I told you here that there was one change from the given formula which you wrote down. Did you read that message
No
You're ignoring the "without a lid" part of the question
i thought it didnt matter
.
Only the volume remains unchanged.
ohhh yeah
so are we subtracting an area of one side?
which is the top
Right
This should be easy now
I mean you should simplify but yes that's right
Yea now and only now can you start thinking about calculus
okay
If you don't know your basic volumes, surface areas, etc. you should not be thinking about calculus
i do know
?????
Yea that had nothing to do with volume or surface area of a box
Do you know what those words mean
such that the gradient vector of the level curve at some constant is a scalar multiple of the gradient of the objective function at that same point
What's the level curve in this question then
i have no idea
thats the thing
but i know we need one
im gonna assume its the contraint fomrula since all our level curves are considered the constraint
but i dont understand why thats the case
Your choice of f and g are fine here. Do you know what equation you need next from the words you just said
i dont know tbh
because to begin with i dont even know how the concept of critical points on g = c applies here
Maybe since you can't come up with an equation, you should just memorize the equation
$\grad f(x, y, z) = \lambda \grad g(x, y, z)$
pi_day
i mean as much as i hate memorizing and not understanding, how do i "memorize" what my constraint is here
which one is the level curve
Do more problems and see what works
but theres gotta be properties that renders one a constraint formula that we should be able to identify right
In reality, it doesn't matter which one is f and g. Solving
grad f = lambda * grad g
is the same as solving
grad g = (1/lambda) grad f
Since lambda doesn't matter, and only x, y, z, your answer should be the same
You should just memorize the blue box here
https://tutorial.math.lamar.edu/classes/calciii/lagrangemultipliers.aspx
And do the calculations in example 1 since you need to read a lot of examples. They will be nearly identical to your problem.
In this section we’ll see discuss how to use the method of Lagrange Multipliers to find the absolute minimums and maximums of functions of two or three variables in which the independent variables are subject to one or more constraints. We also give a brief justification for how/why the method works.
@honest idol Has your question been resolved?
Wait you kinda got a point
So I can scale whichever vector right
Like either one can be the scalar multiple
Did you calculate this yet
Or read example 1 yet
I’ll continue tmrw in the morning or something
Thanks for your help tho
Btw is this right
Like the vectors are parallel
So you can scale either one to get the other
Right
You keep focusing on the wrong things
Do one problem completely before moving on
.
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any insight on how to solve since i don't find any option related to the outcome of the equation i worked
what did you try?
!show
Show your work, and if possible, explain where you are stuck.
do you know that conventionally
(sin(x))² = sin²(x)
yo biscuitt 👋
yes, then?
and
1/sin^2(x)(1+tan(x))
ah, sorry I didn't read well, lemme check
i see now, so can you continue from the last line
no, that's why i'm asking
hm.. i would say it should have been $\sqrt{1- a^2} = |\cos x|$ but they do not seem to consider that
professor paradox
like $\frac1{\sin x}+\frac1{\cos x}=\frac{?+?}{\sin x \cos x}$
Biscuity
do you know what will be in the ?'s
sinx+cosx
yea
now we have sin(x) + cos(x) as the numerator
we tryna divide the numerator by sin(x)
we can get 1 + cot(x)
all good till here?
yeah
after that we just plug back in to get the answer
usually for me, i will just first break all stuff into sines and cosines, and then compact the factors so that it can be in one term
finally check to see if which choice is good to transform into
e..g. i look at E, and see there's (sin x cos x) in the denominator
then I'll aim for that option E
Hope that helps!
it's .close
.close
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hello i had this question and i just wanted to know how it should be approached first and what the idea is here?
do you know how to do polynomial long division?
Guys what is 1 plus 1 equal
um idk 2?
Don't troll
sure
Good boy correct
thank you
What is sin
Dude don't troll
its when you do a bad thing
thats the first step im guessing?
Rebelling against God???
yes
i mean
after long division its preety simple
Try to do polynomial division
let me give it a try
because long division allows you to identify the asymptote
yeah well the green ones have dominion over the help channels
my problem is the a
hm
instead of a
imagine that its a 2
or a 67
anything
and then just carry that 67 over
explanation
ill let googoo explain then since hes already doing well
goodluck
cheers
Want mod ping again?
Didn't help and send random stuffs
i was just talking and you came in and starting calling me a clown
@upbeat swan did i not just offer to help?
🤣
right now the asymptote i got is 2x+(a+2) so im guessing i should equalize the (a+2) and the -4?
@vague phoenix lets just stop the beef alright
yes
correct
and its equal to -6
just set 2x+(a+2) = 2x-4
Yoo
yeah
the 2x cancels
yeah thanks mate
no worries
sup
how do i unoccupy the channel?
.close
Am new here
.close
cool
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ofc
do you have a question?
@vague phoenix do you forgive me bro
check #❓how-to-get-help
I want you guys to asses me I like math but am bad at it
how old are you
how did you end up getting a beef w him lol
hes chill
Am junior at highschool
i mean usually how it goes here is you ask a question and we guide you through it
I don't have any question right now
pretty much i asked a question about which maths to focus on in relation to quantitative finance, he told me i was asking "off topic questions" i tried explaining that it wasnt and it was directly related to maths, he had a go at me and called me a clown, then 3 other dudes actually came in and answered my questions
fun times
oh
lol
i dont want beef with people in the server tho
so hopefully everything will be well and good
16/17
U can tell how old I'm if I told you my grade
no because the grade structure is different where i live
you would just be called yr 11 here
Oh am 18 yr old
No I started 1 yr later
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Can u convince me
am open
hm
this channel is for specific questions
if you wanna talk about it
we can go to the discussion channels
Ok
.close
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interesting
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Hi. This might sound silly. I’m a secondary school maths teacher and I’m marking an assessment I gave to one of my classes. This was one of the questions. I attempted the question in two different ways and got two different answers. Method one is the correct way, but I don’t know where I have gone wrong in method 2.
hmmm
Strange, they looks both valid.
<@&286206848099549185>
interesting
I don't find an error for the second method.
Ah I see why!
For the second way you found, if a = 14.8, then R = 54.8
This contradicts with the given information of the question, where PQ=20*sin(R)
Even though your second step is in fact correct, but if plug back into the original question information, it did not satisfy the given conditions.
I'm finding inconsistencies in the triangle
You can test for R such that $PQ=20sin(PRQ)$ such that $PQ=15.9$
Minλ
Does this make senses @terse burrow ?
I don't think it's a possible triangle, which is why the answer for a cannot be consistent regardless (but I could be wrong)
If we take the answer for a = 12.655 deg, the sine law is not working
When a = 12.655 deg, then <QSR = 180-90-a = 77.345
Hence, <PSR should = 180 - <QSR = 102.655
Using sine law on the upper (non right) triangle, sin(102.655) / 20 should equal sin(40) / 12.7 I believe?
But I'm getting 0.0488 ≠ 0.0506
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No problem, good luck in teaching!
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can anyone help me understand logarithms ?
do you have a problem you were stuck on?
Any particular question?
nope
i just came into 11th and wanted to discover it as my first chapter
Have you taken a look at your textbook?

yes yes
i have applied mathematics
i dont quite understand what logs are for ? are they for finding a power ?
Well, just to start, you should know that the main purpose for logarithms to exist (as they were first created in ~1615) is that they have the main property of transforming multiplication into addition.
Since addition is a far easier operation, they created tables so you can find the logarithm of the numbers you want to multiply, and the number you get from it
This is because the logs satisfy the property
like that a^m * a ^n = a^m+n ??
log(a) + log(b) = log(ab)
So, for example
uh huh
Say we work in logarithm base 10 (we will see later what that means)
and you want to compute (easily)
134 * 211
Well, by property of logarithms we have that
oh is that so, without multiplying ?
log(134 * 211) = log(134) + log(211)
damnnn
you can then compute the sum of logs.
ohhhhh so i would require to look into the table ?
niceee
log(134) + log(211)
2.1271... + 2.3243... = ~4.45138
mb, you can see above what those numbers are
its the numerical value for log 134 and log 211
ow, so i would again need to look into the table to find the answer and then know what it is ??
Then you look up what number corresponds to ~4.45138
yeah, i get it now!
and you would know that the multiplication = 28274
just by looking at 3 values on a table
sweet!!
here’s some intuition you should build
$\log_{x} y = z$
just means
$x^z = y$
so when you are given something like
solve $\log_{2} (4) = x$
that just means
“what number $x$ can i raise 2 to in order to get 4?
thank you for your help man !! really appreciate it