#help-36
1 messages · Page 282 of 1
minus plus
sub in our values for a and b, you get 4 complex solutions
simplify the radicals into x+yi form
and we get our answer
is this still for Q:iii?
Yh
take our answer and we now write: $\sqrt{16 \pm 30i} = x+yi$
KB
square both sides and equate Re(z) and Im(z) components
I did that for the - root is my working wrong
Aren’t my signs wrong ?
KB
I got -5+3i so the signs are opposite in my working but they’re the same here
Sorry I’m just a bit confused
you get part of your solution by solving one combination of sings, you get all solution by solving for all cases of the signs
you should get 4
only way that can happen is if we have ^ ^
that is one of the solutions
$5 + 3i \
-5 + 3i \
5 - 3i \
-5 - 3i$
KB
Hmmm
looks messy but thats all 4 solutions
Ohhh I see I thought this was only two solutions is it really 4?
yea
we started with y^4 + ... =0
right?
by the fundamental theorem of algebra, there is at most deg(f(x)) solutions real or complex
Yes
we simplified it down to a quadratic thus making it 2 solutions
however, when we subbed back y^2 we found all 4
think of it as $(x^2)^2 = k, x^2 = \pm \sqrt{k} \implies x = \pm \sqrt{\pm k}$
KB
I see
of course this is only for when our degree is even
since taking third root doesnt really help (for solving degree(2n+1) polynomials)
hopefully that all makes sense and hopefully i answered your original question
Yeah u have tysm for ur time
np
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Suppose that the demand and supply for electricity are represented by the given equations. Demand: 𝑄d = 25 – 1/2 𝑃𝑃 Supply: 𝑄s= -5 + 1/3 𝑃𝑃 where P stands for price, Qd stands for quantity demanded, and Qs stands for quantity supplied.
b. Despite the increasing deployment of renewable energy, fossil fuels still dominate electricity generation. As of 2026, around 60% of Australia's electricity was produced using coal and natural gas, while renewables accounted for approximately 40% of the total energy mix. This reliance on fossil fuels continues to contribute to carbon emissions and environmental challenges. Suppose that generating each kilowatt of electricity results in an external cost of $5 due to CO2 emissions. Analyse if the equilibrium quantity in part (a) reflect the socially optimal level of quantity? Support your answer by examining the presence of deadweight loss (DWL) on your graph.
so to clarify, your equations are:\
- $QD = 25 - \frac12 P$\
- $QS = -5 + \frac13 P$\
Annie Maqionde
yes
what’s 1+1
when will we use that in real life
<@&268886789983436800> troll
2 i believe🧐
Please dont engage in trolling.
thank you
my bad
not troll bih
don't troll in the help channels
sorry
@night fjord Has your question been resolved?
<@&286206848099549185>
@night fjord Has your question been resolved?
@night fjord Has your question been resolved?
@night fjord Has your question been resolved?
@night fjord Has your question been resolved?
GET OUT
What is part a?
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I feel stuck and I dont know what to do. Please help me math gods
I am confused how to solve 61-66
I'd recommend finding the traces
It's vibes, really.
You should know how similar functions work in 2D, can you recognize these in 3D?
That's why I'm telling him to find the traces. lol
Like, B doesn't have trig in it. See why?
i mean B looks like a plane with some transformation to it
why is there no method to do this omg
i know how to find traces for quadric surfaces but not
Sorry bro, my messages are lagging in here
@chilly rover Has your question been resolved?
can u explain how to solve
<@&286206848099549185>
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<@&286206848099549185>
@night fjord Has your question been resolved?
@night fjord Has your question been resolved?
The diagram appears to be correct
@night fjord Has your question been resolved?
Well, as I can see, you noted the formulas for demand and private supplies are correct.
That addition the external cost of $5 to the private supply curve looks fine too, everything seems fine so far.
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Need help
Right matrix is the adjugate of the left one
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hello can someone help righthere im frustrated
also the picture translated poorly
so i can just do +(7x-14) right
hold up but
how do i know where the tangent is
or how do i explain that they have 1 more point together
you have a point
I mean you literally have a point
P(3, f(3))
you have a function
can i just plugin 3
place x in that function
both
also you might wanna algebraicly prove that the value you get from f(3) has only one x solution for 1/3(x-3)^2(x+6)+(7x-14) by expansion
wdym expansion
hell na
i dont have to do that no way
okay so how do i know they have 1 more common point
WAIT
nah nvm
yeah how do i show they have 1 more common point
hmm
then there'd be 2 solutions to f(x)=1/3(x-3)^2(x+6)+(7x-14)?
I think
or just draw the line on the graph
shit
graph the line y=7x-14 here- hey wait a minute
yeahh ill try in a bit
nah wait u can just sub twin
I am sorry, I don't really understand what the objective is
Do you just have to show that $f(x) - (7x - 14) = \frac{1}{3} \cdot (x-3)^2 \cdot (x+6)$
it seems to be proving y=7x-14 is tangent to f(x) at 2 points
or something
I don't understand german enough for this
@copper roost I will be eating dinner direct questions to someone else in the meantime
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Hi guys, I'm stuck on question 3, will you have a small clue on your side that could be useful to me?
It's my job for the moment, it's written in French if you don't understand don't hesitate, question 2 is badly written I'm rewriting it
havent taken a look at the question itself but i really just want to say
your handwriting is gorgeous
Haha, thank you so much! I must admit that the year of medical school I did helped me quite a bit with that.
@rugged spade Has your question been resolved?
Looks like Tanguy Rivoal is one of your professors 🙂 Just a guess
you know the goat
respect
I don't know if it helps but you may find this proof in a work of Nesterenko himself. It is in Russian, but nowadays with AI it's not a big problem. Here it is.
I'll take a look, but I have to admit the question is really, really difficult for someone my age. He went a bit overboard on the subject, even though he told us he modified it to make the first questions more manageable.
Beukers' proof is the easiest.
Yes, but here we're dealing with Apery's theorem; otherwise, there's no point.
both prove irrationality of zeta(3) which is a proclaimed goal of your tasks
Apery mentionned
but i'm agree with you
But I'm a bit too lazy to get lynched by my teacher.
xD
Apery was the first to prove irrationality of zeta(3). There are many variations of that proof. The easiest one imo is Beukers' proof.
Okay, I'll look into that, even though the last questions are really about Apery, and ultimately what this theorem proves.
The questions are actually there to guide us and put us on Apery's trail, even though from what I understand it starts roughly the same way with other proof
you are french ?
If you need to answer exactly those questions then just do them. If you want to prove only the final result about irrationality I think the easiest is this paper. All these proofs on the whole give the same approximation sequence for zeta(3). Though there are many different ways to get it.
no
Idk if it's for me and if i have the level
i'm 18 xd
the final result was to hard
You just need to know integration. And it is a way lower level than those complex variable G functions in your questions.
Okay, I'll go check that out.
ok its very easy tf
I don't understand why I'm being made to suffer so much, and why I hadn't thought of this before.
Because the irrationality of zeta(5) is still unproven, and no one knows for sure which approach might succeed in that case. So, you should know all of them to be prepared.
who knows 🙂
I'm an idiot, man. The more I improve, the more I realize I could never actually be good.
that's a normal way of thinking. This is motivation to get better
All things should be assessed in comparison
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im struggling with C, I can't understand the question
what does the term "donation rate" mean to you?
(in fact you've been using this value all along in parts a and b I presume.)
1/30 people
well I was asking for its meaning. also what does 1/30 people mean in this context?
1/30 people making blood donations in australia in a week but also its probably not relvant as it was for a prior question
how did you get the figure of 1/30 people when the population of Australia is not given?
also, a week?
the figures in the question are per year, unless this is a continued question from somewhere else.
(in which case your figures do not apply, and you should look at your answer for part a) instead.)
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can someone help me find the third derivative
i dont understand why they've done this
Do you know the rule for the second derivative?
The third derivative is merely the second derivative, of the first derivative.
$\odv[order=3]{y}{x} = \odv[order=2]{}{x} \left( \odv{y}{x} \right)$
Cark Marney 🐢
Or t in your case
@rain sentinel Has your question been resolved?
yh ik that rule
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howmdo we rearrange to get Ys
Factor y
factory
hello guys i need your help. I have a mathmatics exam about limits , integration and other concepts related so I want some videos to solve with calcluater
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??!
Please read the message below it.
ok
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I have to simplify these vectors, how do i do it? for example on a) im stuck on OB + AD and i dont know what to do next since they are different letters
I think that is the simplest form.
it's just those unless they have values
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$y=xy'+y'-y' \ln{(y')}$
DeC∆rbonizeD
looks like clairaut
ln(dy)-ln(dx) 
never heard of it
cookin
its equations of the form y = xy' + f(y')
standard way is usually to differentiate wrt x and then you should see something pop out
yes
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The AM of two positive integral nos exceeds their positive GM by 2 and their sum is 20 find the numbers
! 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
1
Start by giving a name to the two numbers
Let a and b be two positive real nos
Yes
Nope
Do you know what AM and GM mean?b😅
Oh ye
I mean i dont understand the q
Thats why i came here
How am and gm are related here
The question simply asks you to find the two numbers
Do you know the meaning of the word "exceed", like the English meaning, not math related?
Crossing it
Like going forward
By 2
Am plus 2 = Gm
That's a possible interpretation yeah
The other way round
How
If A exceeds B by some quantity, it means that A is larger than B
Yes
Then that's it 😅
Am plus 2 greater than gm
Bro but airthmetic mean is exceeding gm
Yeah
Like am is 2 steps away from gm
If A exceeds B by some quantity, it means that A is larger than B
Alr so to make it equal i get it
U subtracted 2
?
From am
I don't get you
Nvm man
I was confusing myself
I got it now
Really sry too much sequences got me
.close
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I need help with 61-66
please for the love of god
I have my exam and i feel suicidal
looking at these graphs
Look at the function on the axes like I suggested last time.
And avoid pinging helpers right away please
You can rule out graphs based on "easy" places to evaluate your function.
Say for 61, if you plug in y=0, you get z=0. That means that for any point (x,0), the output is 0.
Similarly if you plug in x=0, you get z=0, so any point (0,y) has output 0.
This means you should expect the graph of 61 to be 0 everywhere along the x and y axes.
Well z is a function of x and y
So along the axes, z should be 0.
A doesn't have that for instance. If you follow along the axes, it doesn't look like z=0.
Orange is following the output z along the x axis.
Green is following the output z along the y axis
oh mai gah
Well if you follow the x and y axes for C., it's not very clear but the function is 0 along the axes.
Usually, setting x=0, y=0 and x=y should give you a lot of information.
If you set x=y, then you get sin(x^2), so that means that following the line y=x in the xy-plane it should oscillate.
So here green is the output on the y axis, orange is the output on the x axis and pink is the output along the line y=x.
You can try the other graphs to see if they work too, but they all fail one of those requirements, so 61 would be associated to C.
Wow as someone who is in high school seeing this im shocked what is that
-# When you learn about functions in highschool they're usually functions of one variable. Their graph is like a curve in the plane, like a string in a certain shape.
-# If you add a variable, what you get is a surface in space, like a bedsheet.
I feel like it’s also vibe game
I regret taking calculus 3
and i regret signing up for engineering
Yes it's not an exact science you just have to rule out some of the choices
y=0 gives x/(1+x^2)
x=0 gives -y/(1+y^2)
x=y gives 0
Those graphs mean that along the x and y axes the function needs to have one bump above the xy-plane and one bump below the xy-plane.
Like this
Those are lines you expect to be on the graph.
They're what you get when you set x=0, y=0 or y=x in the function
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Guys what the flip am I supposed to do
I AM DESPERATE
<@&268886789983436800>
Simplify the bracket.
Okay wait can I show you what I did so far and you tell me if its good?
You can cancel the second fraction.
shared factor in second fraction
notice (x+4) is in the top and bottom...
Notice they both have (x+4) on the numerator and denominator.
Yes.
English please
Like that
Because they share same term in multiplication.
So many bots today.
Correct, they do the same method.
Right, both can be simplified in the same manner of canceling out common terms.
(3x-2)^2 is just (3x-2)(3x-2)
Which I saw you already did with the 3x-2
Like that?
Yes.
Okayy omg THANK YOU GUYS
Now, let's clear up the right hand side.
Yess
now you wanna divide that trinomial by 2x-1, right?
Yup
have you learned synthetic division?
Hm i dont think so
Long division?
Long division is more familiar by the students, but depends.
Ya no I need to do it the long way or my teacher will think I used ai or something
lmao
sounds like a teacher
Don't think that will be the case.
As long as you understand it and can redo similar problems.
synthetic division is just the same thing as long division it's just less complex looking 😭
if you wanna do long division, you can set it up the same way say you woul do 500/12
stop the long division hate
tbf u need long division when its not a linear factor
so igs long division still good
Fair point, or when you got a solution.
real people use factor and remainder theorem
Can you solve a polynomial that can't be used by neither of them?
-7 -(-1)=-6
it looks right
The second subtracting part.
OMG YOU ARE A GENIUS
No worries, you are doing fine so far!
oh yeah didn't see that
yeah should be -6x+3
OMG TY GUYS I DID IT
I also didnt understand an other problem but its in french so-
Ask away!
we can try
Aww ty I couldn't have done it without you guys 🫶
Just tell us what the questions mean in the scope of your understanding.
i mean i dont know french but um as long as its not a word problem or u can translate or we can use google translate
Perimeter
Ah okay.
You use Pythagorean formula?
To find x.
Then you can substitute back into the result P=10x+30 you just got.
Do you know the pythagorean theorem?
The triangle rectangle PQR has these characteristics
Put your answer in numerical form what is the perimeter of the triangle
I think she is still translating 
Yup
So can you apply them to the 3 sides?
ah... i lwk just used gemini to translate-
Since it is a right-triangle.
Wow. I can read a bit French so I got it straight away.
Ayee period queen
i know no french ... i knew the quetoin asked something about ... a triangle. i only speak english and chinese.
Anyways, the Pythagorean formula can solve this by setting RQ^2+PQ^2=PR^2
.pin
Haha!
well... same result anyway xd so how would you apply pythag theorem to this?
Just use google translate....
i didn't wanan type allat...
Holy molly my translation is kinda good yall
It does!
(I believe after pythag theorem, you would end up with a quadratic that you'd solve for)
^
place the x on one side and solve for (usually) positive x values
You realise you can just react, not to type "^" right. 
-# I'm stupid and my default is reply and ^
lwk real i do that too
Just set "^" as your default emote.
Ah, I think that emote to be set by default, you need Nitro.
^ @mystic lotus how are you doing on this so far?
looks right
Okay but like what do I do now
Bring it back to 0?
Make one side 0 by moving the stuff on that side to the other side by performing the appropriate addition/subtraction
id recommend moving the left side to the right side
Yes.
mmhm.. look for anything to make factoring easier (any gcfs youre noticing?)
Like that?
did they tell you where the right angle is?
you may need to go through all 3 cases
It did.
Here for your information.
where
^
that doesn't say where the right angle is
Le triangle rectangle means right triangle in French.
Ah, I get what you said, you do not know where the right angle is.
igs since q is in the middle its supposed to be more implied
In this case we need to implies 3 cases.
No, that's too random and intuitive.
one case flat out fails,
one has ugly values
one has nice values
Did the question specify where is the right angle?
er.... probably
Hm no
did ur teacher mention anything bout this problem?
Nope
Hmm, I think in this case, solve for the assumption you are doing then ask your teacher a clarification.
Yes, let's cancel out 4.
I do not think this will give us a nice solution.
After this case, let's try if 26 is hypotenuse, that one should provide a nicer answer.
@mystic lotus Has your question been resolved?
I think i will leave it like that bc I learned that my teacher wont even correct jt
Alright, all the best!
Thank you so much tho 🫶
No worries!
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(this might be a better question for the physics server, but) at what angle is the wind relative to you?
and also, for future helpers, what have you tried and what do you not get?
we need more info i think
do you intend to take over this channel again? if yes, I'll leave this one as well.
no, it's fine. carry on please.
-# The profile picture is quite dodgy.
The nickname is not bad, but the pfp does.
i think the nickname refers to epstein's email
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Basic question perhaps. The author says gamma is a curve in R^3. Why is the 1-form using the coordinates x and y, when the curve could have non-zero z-coordinates?
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the line of intersection is given by cross product of their normal vectors
Ohhhh
And then I have to find any point at which they intersect ?
Yes
Any point works
@raw patrol Has your question been resolved?
For the first question (27a), just set a cross product.
Then find a point on l by setting z.
Hope this helps.
Can you elaborate on setting z
Well, suppose we let z=1
Then we can continue from there.
Ok
Please ask straight away!
Have you finished the previous question by any chance?
Yes I have
It makes sense now tysm
No worries.
I kinda gave up and looked at the MARKSCHEME and I’m just a bit confused where they got the second line from
Ah I see.
Let's resolve it together.
The problem states that for any normal to plane A, then components of x and y are normal, right?
Yeah
Yep
Now, what is a general equation for a plane?
Correct, we will do with the first definition.
Oki
Now, for plane A, it contains point A (3,-2,-1).
Can you substitute it into the equation?
3x-2y-z=d
Substitute in here.
Then it would be something like 3a-2a-b=d_A.
Ohh ok
13a+10a +9b =d_B
Now, do you know the distance formula?
Not for Planes
No worries!
If I didn’t know that is there another way to get there
I just googled the formula up, haha.
Cuz I only know these + the angle ones which are in my formula
Booklet
Ah ok
Ah..
Yeah that’s why I was so confused
They should have added that formula into your formula sheet in my opinion.
Is there any way to do it without knowing the formula ?
Maybe you could try using distance between point and plane?
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how do i do for b?
@faint monolith Has your question been resolved?
@faint monolith Has your question been resolved?
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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
can u offer a translation in english?
1
thx
r'
How do you compute the velocity of a parametrized curve?
Yes I get that it's denoted r' (well here σ'), but can you compute it?
component wise computation
Okay which gives?
r'
Can you write down what σ' is?
,w differentiate r(t) = (t - sin(t), t - cos(t)
Sure well that's your velocity.
Do you know what speed is?
r
ohh
So now that you have σ'(t), what is the speed?
||r'||
Yes
,w magnitude (t - sin(t), t - cos(t)
This is neither your position function nor your velocity.
is sped
You need to take the magnitude of the velocity
(t- sin(t), t-cos(t)) is not your velocity.
Your position function is (t-sin(t), 1-cos(t))
@blissful meadow
Not (t-sin(t), t-cos(t)).
,w differentiate r(t) = (t-sin(t), 1-cos(t))
You're making this harder than it should be by not computing it yourself.
,w magnitude (1-cos(t), sin(t))
Okay you may want to simplify it.
Then you'll need the arclength.
Do you know how to compute the arclength?
yes
It's written in your book the arc legth formula
This is not the arclength of a parametrized curve.
It's the arclenght of a function y = f(x).
Then compute that. You've already gotten the speed.
what is ab
The endpoints for your parameter.
You're told to compute the arclength between the points r(0) and r(2pi), so the endpoints for your parameter are 0 and 2pi.
You've already computed the speed.
The integrand should be the magnitude of the velocity, i.e. the speed.
Renato
@blissful meadow
Sure, you've already computed that.
what
You'd already computed the speed there's nothing to check
the integral of this?
No
Now you can compute the integral.
You may want to expand things under the root.
is hard
It's not that hard if you expand things and simplify.
1-cos(t) is not sin(t).
how to conclude
Trig identities. $\sin^2(\frac{t}{2}) = \frac{1-\cos(t)}{2}$.
Azyrashacorki
yeah I'm not that advanced
This is not advanced.
It's a common trig identity. If you don't know it then you should get to know it.
name
this comes from rearranging the double angle identity
cos(2x) = 1-2sin^2 (x) where in this case x = t/2
is it possible without
Not really
trig is scary
You can't be afraid of trig if you're doing calculus!
Willing or not
trig is a crucial part of calculus and it is extremely important you know your way around it for calc
-# especially when you're at the point of doing multivariable calculus
Then you solve the integral
That's a single variable integral which you should know how to solve
,, \int_0^{2\pi} 2\cdot |\sin(t/2)| dt
Renato
how
How what?
abs is giving trouble
That shouldn't...
If it does, revise the definition of absolute value
As a piecewise function
what about it
Maybe.... use it???!!!
can I just ignore the abs
Look into the sign of sin(t/2) in the interval [0,2pi]
No, you can't.
- 1<= sin <= 1
Yes that's in general.
0 <= abs sin <= 1
trig scary
But for t in [0,2pi], what can you say about the sign of sin(t/2)?
Result:
1.2246467991474e-16
STOP SAYING THIS
Also sin(0) and sin(pi) are things you should not need a calculator to check
we would need to find the critical points and analyze the func
Also because this might deceive you and think that it some non zero number
No. If you remember the unit circle you should be able to tell instantly what the sign of sin(t/2) is for t in [0,2pi].
(x,y) = (cos, sin)
You may think of it as studying the sign of sin(x) for x in [0,pi].
What is the sign of the sine of an angle if that angle is between 0 and pi?
posi
So sin(t/2) is positive on [0,2pi].
how?
Wdym how
t ranges from 0 to 2pi, so t/2 ranges from 0 to pi.
You agreed that the sine of an angle between 0 and pi is positive.
this argument doesnt uses unit ci3cle
@blissful meadow
You literally drew the unit circle
also not necessarily if thta is in third or 4th qudrant we have negative teta
is just above 180
ohh
Yes, hence why sin(t/2) is positive between 0 and 2pi.
t ranges from 0 to 2pi.
t/2 ranges from 0 to pi.
So t/2 is below pi.
So sin(t/2) is positive.
how
how
sin(x) > 0 forall x in [0, pi]
between pi and 2pi what happens
@blissful meadow
Then it's negative but that's not in your interval
how is negativo
@blissful meadow
Wdym by how?
It's like that.
same argument as your unit circle
But the angle is between pi and 2pi
So it's below the x axis.
So the y-coordinate is negative.
In any case, sin(t/2) is positive between 0 and 2pi.
and y coordinate is sin
What can you say about |sin(t/2)| between 0 and 2pi?
= sin(t/2
Yes
so i can ignoee abs
So then you don't really need to deal with the absolute value
In this specific case.
,, 2\cdot \int_0^{2\pi} \sin(t/2) dt
Renato
,w cospi
you should know the value of cos(pi)...
trig is hard
if cos(pi) is hard you should definitely go relearn and fully understand the unit circle
2[-2 + 2] = 0
-# (Note that a good way to see something went wrong with the signs is that it makes no sense that your curve would have 0 length between 0 and 2pi.)
why
Because the only way your curve would have no length is if it's just a point, which it clearly isn't.
why
ragebait
why do you say that the arclength would be 0 iff its a point
is that very intuitive to everyone?
What's the dimension of a point
It's sloppy but P and Q are vectors
The arclength is the lenght of the curve. It's always nonnegative. The only way it can be 0 is if your curve is just a point, otherwise it would have a length
In other words you would need ||r'(t)||= 0 for all t. And this describes a parametrized curve which is constant, i.e. a point.
(1,1) is a parametrized curve which is the point (1,1) for all t.
ok this is better explanation
Well it shouldn't be unintuitive that a curve having no length means it's a point
and?
i thought i had something
And this describes a parametrized curve which is constant
wdym?
If r'(t) = 0 then that means r(t) = (a,b) where a and b are constant.
Simply by integrating.
But a and b don't depend on t
So r(t) is just the point (a,b)
isee
In this case (and whenever the velocity is 0 for that matter), you can't define a tangent line.
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eh the 11th question
i just didnt understand how that proves abcd is a square
if anyone can help and give me a tool to practice such problems would be much appreciated
oh and help with this problem too
tysm 🙏
question 11
Do you know the definition of a square?
yes
it is a quadrilateral with all sides equal and all angles equal (90 degrees), they shown these features hold and hence it's a square
What part\line is confusing you there?
rather that SP = PQ and that angle SPQ is a right angle (because it is equal to 180 - 2 * 45), but yes - these triangles are congruent
Okay, slowly, let's start from the very beginning
yes ty
Do you understand why AS = BQ?
Ok, do you understand how does that imply that AS = 1/2AD and BQ = 1/2BC?
Okay, so the first line is clear
yeah
same thing happened in the 2nd line, where AP = BP = 1/2AB (midpoint)
yeah
angle SAP = QBP = 90 deg because ABCD is a square, right
yeah so sas congruence?
Yeah, exactly
okay got that
so ASP and BQP are congruent
yeah
this means that SP = QP (because if SAS holds then also SSS holds)
you could repeat this pattern 3 times for each pair of adjacent triangles (corners) and you would get that all sides of the quadrilateral PQRS are equal
Do you see that?
yeah
Now notice that these corners are isosceles right triangles, so their acute angles are 45 degrees, right?
oh yeah
e.g. in SAP you have SAP = 90 deg, so ASP = APS = (180 - 90)/2 = 45
one last thing - angles SPA, SPQ and QPB are adjacent, so their sum is 180 (the same for the rest of the triangles)
and hence SPQ = 180 - 45 - 45 = 90
this proves that all sides and all angles of the quadrilateral PQRS are equal, so (by definition) it is a square
oh
this was really help ful
i rllly appreciate it
do you reccomend any place to get practice problems like this one
isn't there more of this in the book/textbook?
If you have the answers (as above), you can practice, understanding comes with time, do 10 such tasks and you'll get the hang of it
the first picture I found on the internet (the quality is terrible, I know, but it's readable)
just search "basic geometric proofs exercises" or smth like that
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How do we get that the supremum exists on this open set from the fact that g is continuous?
isn't that extreme value theorem
hello!
do you still need help?
it is
since $r < 1$, the closed ball $\bar{B}(0, r) = {z : |z| \le r}$ is a compact set contained within the domain where $g$ is continuous (assuming $g$ is defined on the unit disk)
W*
so by EVT, $|g|$ has to achieve a maximum on that compact set, so it's bounded
W*
the sup on the open ball is then just bounded by that max value lol
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(k) $|{f : \mathbb{R} \to \mathbb{R} : f$ is continuous}|
toast
Compile Error! Click the
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(You may edit your message to recompile.)
alright ill try this problem now
(k) ${f : \mathbb{R} \to \mathbb{R} : f$ is continuous}
toast
one thing that it implies is that if you specify f(x) for all x in Q, then that uniquely determines f
hmm wdym by that
