#help-23
1 messages · Page 369 of 1
I can give it a go but I think your intuition is much nicer
yea i don't like definitions that use nonexistence over ones with existence
Fairs
another instance of this sort of way of defining things comes up with connectedness if you get to it
I think I’m just having hard time just juggling real analysis mindset rn
not sure if this is for a real analysis course or if your course even dabbles in metric spaces/topology
It’s real analysis
my analysis course covered metric spaces in the second half
not all courses do though
I mean I’m up to continuity, have done ratio tests, sequences series etc
I’m just revising rn
And it seems to be more difficult
well i guess you're studying for finals
Yea end of term exam
so it wouldn't be in the course
Yea
good luck sir
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✅ Original question: #help-23 message
@severe pond sorry for taking ur time again, was this the overall logic we had?
Just rewriting it
Wrong way at the end
b>=M
Definition should also say s of E instead of s in E
It’s calm I see it
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@opaque fern hiii, im back
(need some help with part b with determining which parts/sections of each curve i need to subtract to find the shaded area)
@obtuse kettle Has your question been resolved?
then double it
you should be thinking of polar area as standing at the pole and shining a flashlight at the wall like i’ve drawn here
the wall for the first bit is the circle
then afterwards it changes to the whatever you call it
C_1
So for the yellow part, im integrating using C2 and for the red part, im integrating C1?
yes
thankss!
then you double it since it’s symmetrical
Yuppp
you’re welcome
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sum1/(x^(m - n) + x^(n - p) + 1)
@lean otter Has your question been resolved?
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I was looking at the gradient vector when studying for my multi calc final, and I still dont understand how it is defined as being perpendicular to the tangent plane, because i remember that the gradient vector is the normal vector for said plane, so the reasoning feels circular. Is there something im missing here?
the gradient vector is the normal vector for said plane, so the reasoning feels circular
is that the definition they gave for the gradient vector? if not then there is no circular reasoning
normals should be perpendicular to the tangent plane
so like, it's just saying the same thing
but like why is it the normal for the tangent plane
in this presentation, that's the definition of the tangent plane
which is motivated as being the plane containing the tangent vectors to any curve on the level surface
and as they showed, the gradient is perpendicular to all of those tangent vectors
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what are the components of v if v = 2t + 3p -s t = (20,49), p(21,12) and s(-13,18)?
hi opal
First find 2t, 3p and -s
whats up
nm jst OVERWHELMED because the exam got postponed again
actually i finished it but my answer gave none of the right answers i have 2t 3p and -s
more tim to study
Well 2t 3p and -3 aren't the solution
i put it in the equation wait ill do it again
What equation?
oh wait i think i put them in norm
to find v
i found the norm for the components
then i multiplied like norm for t is 2(t)
nvm
What are components of a vector
the sides
all i have to do is multiply t by 2 and p by 3
then add them?
after subtract by s
USS-Enterprise
And you get vector v with (2t + 3p - s)
And I assume you have learned how to add and subtract vectors & multiply vectors with scalars when they are given in component form
so add vector t and p?
yup
Then that's all you have to do here
2t + 3p - s
You need 2t, 3p, and -3
So just multiplication by scalars
Then add 2t and 3p - addition
And add -s or subtract s from that
why multiply t and p
oh alright
yeah
ill find it
👍
(40,98) + (63,36) - (-13,18)
Yes
gotcha
And how do we do that?
Sure
I am blind
no wories
alright thank you
no problem!
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Im studying for my midterm but got stuck on this question, how would you do it?
Dont know where to even start
f(x) = the value of f when x=something
when finding f(2), find where x=2 is and find the value of f(2)
Keep in mind that a white dot means the point is not included and a coloured dot means it is
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Why can we use [-π, π] as the bound of the integration here?
Since in the definition of fourier series its 0 -> T
you can use whatever you want as your period really. but it's almost always -T to T or 0 to T
@keen thicket Has your question been resolved?
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lf for someone to explain $\int{\cot{^{-1}(x^2+x+1)}dx$ nothing making sense in ts
Cera
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
so i converted to $\tan{^{-1}\frac{1}{1+x+x^2}}$
Cera
You can apply the arctan subtraction formula on $\arctan \left(\frac{1}{x^2+x+1} \right)$. You can also do integration by parts on the original integral directly.
Civil Service Pigeon
whats the subtraction formulae??
ive never heard
you can derive the subtraction version by replacing y with -y
ooh thanks ima try that
it's doable - never said it would be nice tbf lol
but if you don't wanna do fanc(-ier) trig stuff, it works
@fathom plume Has your question been resolved?
i might have fucked it since it looks a bit too nice but if it is how do i deal w $\sqrt{\tan{x+c}}$ term?
Cera
gonna be honest idk where this came from
,w integrate sqrt(tan x - 3/4)
also the antiderivative of the square root term is quite gnarly
you're better off being boring and doing ||partial fractions||
i am interested in this, i only know how to do this using the arctan identity
it's literally just pfd bash
at least I don't see a nicer way off the top of my head
oh fuck no ew
i have $\int{x} d\theta$ where $\tan{\theta}=x^2+x+1$
Cera
lol
oh god
I see where you're going with this now
I thought you were scribbling out all of that stuff lol
that's not gonna go very well though
ye i might back up and do the original tangent diff identity lmfao 😭😭
i thought by parts is gon be easier
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1)If we equate the given to K we get that LHS of what we have to prove is K (P+Q)
Now I have no idea how to ab+ac+ab
in the denominator
,rccw
Oh I think i got it
can someone verify that , it can be solved using multiply letters in denominator and numerator and adding
it
We could multiply the terms by a/a, b/b and c/c respectively
yaaaaaaaaa
Exactly I think so too
Iamma trya
Yea Done
THnek you guys
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In order to try and recover a car stuck in a muddy field, two tractors pull on it. The first acts at an angle of 20° left of the forwards direction with a force of 2250 N. The second acts 15° to the right of the forwards direction with a force of 2000 N. Draw a scale diagram of the situation and find the resultant force on the stuck car.
I don’t understand what I means by left and right of the forward direction
it doesn't actually matter what you set as "forwards", be it north, or east
the important part is only the angle of what you set forwards as
so, it is for you to choose what forwards is and then you take the angle from there
@steady yoke
Now?
it was 2250not 2500 though
ummm i think it's easier to just work out the forces in each direction and then make a triangle
okay so this is the first triangle?
yes
now what
can you find x and y
Yes
okay, can you do a similar thing for the other side?
Wdym other side
other "triangle"
Yes
this one, is the forces going to the left
now do the same thing for the forces going to the right
yes I can do that
I’m not sure
try to think, it's okay to take time
why would I want to work out x and y
okay, what is the question asking for
the resualtant force
right, and what is that
i know what it is myself, i am asking you to tell me
oh i see why you said this, okay
we can do it this way as well i guess
i was going to tell you how to just do it straight up without scale
Can I do it like this then
like how you mentioned originally? yes
Not been taught that yet
ah okay, my bad
Question also dsays
scale diagram
yeah i know, i just thought it would be nice conceptually to do it like this
Understood
well, i suppose you don't need more help then? or is there something you still want
@steady yoke Has your question been resolved?
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So I have been reading up on Tannaka duality and I understand that it allows us to reconstruct a group from its category of reps, but how does the fiber functor come into play here exactly? Since the group we recover is defined as the automorphisms of the functor, does this mean the dependence on the functor mean the group isnt actually intrinisic to the category?
@keen tulip
this isnt my only thign in my mind but i feel like its better to just post this first 
bruh
okay so the basic input for the Tannaka duality is like
[
(CCC, otimes, 1, omega).
]
is that right
yes
クーリー
Are you both doing forbidden maths?🧐
please only use the channel if you have something productive to add.
{}I see wait so the fiber functor
[
omega colon CCC to Vect_k
]
is what lets you forget the group action but remember the underlying vector space basically.
So, for $CCC = Rep(G)$, $w(V)$ is the vector space underlying the representation of $V$, adm morphisms are sent to linear maps. That provides a linear realisation of the abstract tensor category.
クーリー
silly preamble
So once you have $omega$, you can define
[
G coloneq Aut^{otimes}(omega)
]
which is the tensor-preserving natural automorphisms of $omega$.
wot does linear relisation mean
クーリー
also btw what happens if the functor doesnt exist
are u just
unable to recover the group
i get that
A linearisation of a tensor category C is a faithful, exact, tensor functor which realises every object of C as an honest vector space and every morphism as a linear map, compatibly with the tensor structure.
I think
bruh why is my wifi not working
I think a category is called neutral Tannakian precisely when such a fiber functor to Vect_k exists.
okay
okay
okay
this is awesome
I only mean like in contrastf to something that's abstractly behaving like a vector space inside a category
indeed. I shall be helpful in no time
I think that's the term they use honest.
bruh where are we now
all we have said so far is like
the functor is the tool that translates abstract category to vector spaces
I think the crucial part is like it fixes a base point
wdym
and it ensures every object is realised in the same linear universe, so a single automorphism can act coherently on all objects.
just that it's a choice of base point
ok i get that
oh yeah
is the group gonna be unique
like are any two fiber functors isomorphic
i think thats basically another way to restate my og question


okay okay wait
I think I do recall this
If C is neutral Tannakian over an algebraically closed field (or more generally if a fiber functor exists over the base field), then any two fiber functors are isomorphic. This is true because (I think) the collection of fibre functors is a torsor under the group you are trying to reconstruct. This means any two fiber functors are locally isomorphic, but there may be no canonical global isomorphism between them.
one second lemme look up something
wait so
if the fiber functors form a torsor
then effectively
wait
im confusing myself
one sec

like
the gerbe of the category is gonna be the stack of all the fiber functions correct?
so saying a category is "neutral" is just asserting that this stack is trivial or whateveer?
Yeah
what about if its not neutral
i.e. admits a section
does the group still exist locally
ok ofc it does

but then
the torsor has no global point ig?
So the group exists locally but doesn't glue to a global group over k
what is k
The base field
Blud udnerstands it now
pogchamp
u barely help bud
alright lil blud

No way
This is gonna be the end of me
who even decided this
I shall have a word
.close
blud can't even close
blud has no authroity
back when i switched accounts
they gaev me access to helpful lounge
manuaklly
without having helpful
bcuz my old account had helpful
bruh no one told me about this
Is it still possible though
idk try ur luck. show them ur olad account's id
Maybe I should modmail
okay
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Hello
Am I doing this correctly
your answer to 2. doesn't look like it's degree 3 from where i'm sitting
Well
(x - 2)(x + 3) has leading term x^2 if you expand it out
Judging by the first sentence
so that has degree 2
"now we reverse the process"
implies we don't see everything
may we see everything 🥺
I think that's just a transition
Finding roots
what is "degree of function"?
That is also my question
don't they mean degree of polynomial?
Ah yes, very possibly it seems
Guys, how can I make it degree 3
But then this isn't very specific
uss-enterprise, I only ask one question
You need to square one of the brackets
.close
I see they forgot to write a number
at "at, at"
So that's why it doesn't make sense
also should be "function with 3 roots"
(╯°□°)╯︵ ┻━┻
I’m glad I’m not stupid
Yeah
But this example formation is very lazy and disappointing
Not necessarily
Presumably they meant there's a double root
I doubt it
Since "at, at" is written
meaning very likely a number was meant to be placed in between
My guess is they just copied and pasted the first example
But couldn't care enough to change it
Also
Changing my opinion again
Judging by example number 3.
You need to make up requirements which aren't listed yourself
you add another root
so it has 3 roots
HOWEVER those roots can repeat
so you could have (x-2)(x-2)(x+3)
which has 3 roots
but one of them has multiplicity 2, because it repeats
yes that would be my takeaway
It doesn't matter what the third root is
You need to add it yourself
But I stand by my point that these are badly formulated examples
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so basically
higher mean or higher median
the definition i have here says that higher mean or higher median
i mean
try it for yourself
did the system say that it's the correct answer?
but i think that calculating the mean is typically the stronger option
i personally would use mean here
after getting 15mined for a lot of time, now (ask for pronouns) knows what to do
i'd say im mid in desmos
ah
Most appropriately it's C. Mean gives an overall gist.
Let's take a smaller example:
Team A : 66 67 69
Team B : 66 67 68.
Median is 67 in both. Mean differs. Team A, W
also don't ping helpers when it's not 15 minutes for the sake of god
@patent musk Has your question been resolved?
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The ratio of highlighter to felt tips is 1:6. The ratio of felt tips to pencils is 3:2. GIven that she has ten more felt tips than penicls, how many highlighters does she have?
I did H:F:P = 3:18:12
Then she has x pencils and 10x felt tips but i dont know what to do with it
nope, she does not have 10x felt-tips
oh nvm 10+x
great, so now 18 parts - 12 parts = (10 + x) - x
yep
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what did i do wrong here?
i mean i know its the 5th step but idk why its wrong
I'm not sure why you putted 1.75 at the left top. But when you log both sides in step 4, you get $\log(1.75^t) = \log(\frac{N}{20})$
MxRgD
wym put 1.75? all the way at the top is the question
ohh nvm
Okay i see what you mean, but you don't have to convert them into that form in this case
i tried to use this
do you know your log laws?
ah okay
these specfically
ah okay
yeah you need to apply log laws in this case
for example, we can apply the power rule to $\log(1.75^t)$
MxRgD
yeah thats what they did in the book
yeah, log laws are pretty useful for rearranging to make a specific variable the subject
so in this case, what would log(1.75^t) be equal to then?
txlog(1.75)
nice, it would be better to write it as tlog(1.75) as some people might confuse the x as a variable rather than a multiplication
i had already seen it in my book though
can you tell me what i did here that i can not do?
I can go through and explain the steps if you want me to?
sure
no thank you i understand the steps now👍🏼
for example, in step 5 you didn't log both sides
think of log as an operation itself
for example let's say 5 = 5. If you times both sides by 2, you get 10 = 10
but is it "illegal" to do my method this way around
yeah
because the other way around you can do it right?
it's the same as doing log(5) = log(5)
for both sides
yep, it wouldn't make sense if you did multipication on one side and end up with 10 = 5
okay
you have to do it to both sides and the same concept applies to logging both sides
only thing i dont understand
is why it is allowed here and not the other way around
but maybe i should just let that be idk
sorry if i was gone for a bit
had to do something
np
anyways from here that's because it's just using the definition of a logarithim in that being $\log_a(b) = c$ is equivalent to $a^c = b$
MxRgD
so they converted between the two
but why can i not do it here?
as in logging both sides?
oh okay i see what you mean, it's not that you can't do it. You can, but it would not help you rearrange the equation
for example
ah okay
i understand
i find it hard to notice when i can and can't do things like that
if you notice, we bring the exponetial down when we do the power rule
like how do i know which rule i should use
yeah it's practice
okay, i haven't done much of that yet so that is probably the answer then
main thing is when you see something in the form of a^b = c, log both sides to get log(a^b) = log(c), apply power rule to get blog(a) = log(c)
okay
i understand everything now
thank you very much
im going to study like until 3:00 probably hahah
hope your studies goes well!
i'd also like to point something out if you have some time?
ofc
there are cases where the power rule won't work take for example log(x^2) = 2log(x)
the problem is that it won't work for x < 0 for the domain of the logarithim
yeah this is like
but thank you for letting me know
no
they look like this |5|
you can think of it like returning the size/magnitude
so |5| = 5
but |-5| = 5
hm
so in the case, we can apply this to say that log(x^2) = 2log(|x|)
and then you can apply the rule?
yes
ah okay
notice how you always get a posistive number?
but yeah that's like a heads up, they can kinda do these weird tricky examples if they wanted to
yeah they wont tho
students would get very mad
we only get things that we practice (its high school)
alright, if you have no further questions. You can type .close, to close the channel :p
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I don't know where to begin
for starters, i'd look at the roots that's being shown
What are the roots?
when it crosses the x-axis basically, so y = 0
look at the x-coordinates
Oh okay, so that means the roots are x = -3, -2, 1, 2
that's right
you have to know the dominant coefficient'
no i dont know
oh i read the statement wrong i thought u were asking a question
whats the dominant coefficient
Essentially, you have the right equation, but you have to figure out what coefficient goes in front: $y = a(x+3)(x+2)(x-1)(x-2)$
Coolempire93
i think i remember this, we have to use f(0)
Exactly!
alright let me try to solve the whole problem, when i say the answer could u check it for me?
Sure 👍
sherman
i wrote it in latex just for practice
Looks a little large to me 🤔
Plugging in 0 I get $f(0) = 3 \cdot 3 \cdot 2 \cdot -1 \cdot-2 = 36$
Coolempire93
(I think you meant ||1/3||)
oh uh yes sory wrong calculations
oh wait I did $4a = 12$ instead of $12a = 4$
sherman
thank you for teaching me to check my mistakes
😆 Always important
could u help me with this one as well, i don't know where to begin
im guessing i have to open a new channel, alr see ya guys
.close
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Haha not that I didn't enjoy the last one, I just have no idea how to do this one 😂
oh ok. i see
But it's best to open a new one, new people will see it and help
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hey,
if we have a function f: R^n --> R^m
how can we determine if f is deffirentiable in R and in a certain point (x_0,y_0), and find the deffirentiability at this point.
I'd be very thankful if there are more than a way.
thanks
$f$ is differentiable in $(x_0) in \mathcal R^n$ if there exists a linear map L such as :
$\forall h \in \mathbb R^n$
$f(x_0+h) = f(x_0) + L(h) + o(| |h| |)$
as o tends to 0
robins
so ill have to find L(h) that satisfy small-o-notation of ||h|| ?
robins
wait is it the same as Jacobian matrix ??
yes kind of.. but i made an error
this is for functions $f : \mathbb R^n \rightarrow \mathbb R$
robins
yeah i got you
so for functions $f : \mathbb R^n \rightarrow \mathbb R^m$, you can write $f = (f_1, ..., f_m)$ with every $f_i$ mapping to $\mathbb R$
robins
actually, for $f : \mathbb R^n \rightarrow \mathbb R$, we have $J_f(x) = \nabla f(x)^T$
robins
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A motorboat must travel from point A(-1, 4) to point B(5, 7). The units on the plane are in km. There is a 30 km/h wind with an orientation of 25° and a 10 km/h ocean current with an orientation of 110°. The boat's captain wants to complete the journey in 30 minutes. What must be the speed and orientation of the boat's motor?
why do we not divide 30/2 and 25/2
Well why do you want to divide them?
it says in 30 minutes but they're in hour
Well yeah, so how many hours are there in 30 minutes?
there isn't
Well yeah, but we can write it as a decimal
0.5
Right, so just use that for your time.
Divide what by 0.5?
wait nvm
Well, you do have to divide something by 0.5, my question is what :)
hmm
im not sure
Okay well before we figure out these details, let's consider the question at hand - what was your initial plan for solving the question?
well from what i understood
to get to point AB
its influenced by 3 vectors
the motor the current and the wind
so m + c + w = AB
so i was gonna find the components of AB c and w
then i subtract c and w from AB
Good! I just wanted to interrupt you for a second,
There's a small issue with this approach.
what is it
m, c and w, what kind of vectors are they?
I mean,
If you think about the vectors, are they displacement vectors, velocity vectors or are they acceleration vectors?
acceleration
Close but nope :)
ah
Remember that acceleration is distance/time^2, so if you look at the units of these vectors, they aren't acceleration vectors.
wait dw about this cause i dont think i learned that
like those names
nope
That's not good, your teacher should be teaching you what those are
Let me quickly go over them
Because it is actually important you know the difference
my role is wrong im in highschool
alright
Yeah this is high school stuff
Motion is the study of how things move. There are three main concepts that you need to know. The first is distance.
Distance is how far you have 'travelled' so to speak.
which is AB
Now, you also may need to know how fast you are going when you travel this distance. We call this quantity speed. Speed tells you how far you travel per unit of time. In other words,
Speed = Distance/Time
Ehhh well yes, but also no!
the current motor and wind
is the speed
its the distance no?
Now, the last quantity you need to know is acceleration, and it's basically how fast the speed is changing. In other words, it's the speed of the speed.
So, there are three main concepts involved with motion: Distance, Speed and Acceleration.
i dont understand the acceleration
that can also be the wind cause the wind can be changed
The thing is, all of these concepts are missing something. In particular, they are missing a direction.
dw about acceleration for now :)
For example, we might want to ask for distance in a certain direction.
For example, we go 5 units to the right, or whatever.
I.e in principle, we want to link each of these three concepts to a vector.
Hence, there are three different concepts of motion that are related to vectors:
Displacement (the vector representing distance),
Velocity (the vector representing speed),
Acceleration Vector (the vector representing acceleration).
So, here's the thing.
The vector AB isn't actually distance, it's displacement.
I can prove it:
The 'distance' from A to B using distance formula is sqrt(36 + 9) = sqrt(45)
So in particular, the vector representing AB is the point from A to B with a distance of sqrt(45).
Furthermore, these aren't 'speed' quantities, but rather velocities.
alr listen we shouldnt do this
Because they are vectors that represent speed.
this is too smart for me
My guy this is just definitions 😭
All I'm saying is
If you have a vector
And it tells you the speed
We call that vector velocity.
That's it
So the point is that
alright but what does that name do
yup
But the left hand side are velocity vectors
And the right hand side is a displacement vector
So we have a problem, because velocities aren't displacements.
What you are saying here is that if you add a bunch of speed's up with a certain direction, that will give you a position.
But this is not how speed and distance work.
oh so we cant do m+ c + w = ab?
oh alright
well I mean
does it make sense to you if someone tells you that 20mph + 20mph = 40 miles in front of you?
nope
that's the problem with adding speeds/velocities and expecting the answers to be distances/displacements - the units are not correct
or rather they are not consistent
Indeed, we can't - but there is a pretty simple fix. How do we turn AB from a displacement vector into a velocity vector?
Hint: What's the formula for speed?
distance = time/speed
But there is something in the situation that allows us to find a corresponding velocity vector.
mmm this looks like a little strange
If you travel at a speed of 2km/hr for 5 hrs, how far do you travel?
speed = distance/time
10
Consider the situation
You know you have a displacement of AB,
How would you figure out the velocity of the boat going through AB?
i have to do speed(velocity vector) = (6,3)/0.5
Perfect.
(6,3) is the components of AB
And that's why you need all of this :D
everytime i got vectors that are speed and the AB is a trajectory
i have to turn AB into a velocity vector?
velocity* vector
Yes well, it is largely situationally dependent but yeah
The idea is
You want to look at your equation and see if it makes sense
I.e
but one time i didnt
ill show you
OP, are you interested in a way to check your answers thoroughly
Yeah I know
and perhaps catch this kind of stuff
They might give you the velocity vector already, so you don't need to do any conversions.
It's all about looking at what the question has given you
Well here you did convert something, you converted the 40km/h into the 360km displacement vector.
ohhh
alright so even here i did something
Yep
alright ty lets go back
Just as a side remark
There is a small caveat
Oh wait actually
Nvm
I was going to say something but I'll say it later
Anyway, so you have this now.
what if i replace by (12,6)
Sounds like you have a decent idea of how to continue.
yeah
Yep, that's fine.
\[
\frac{km}{\bcancel{h}} \cdot \bcancel{h} = km
\]
just in case
alright thank you for making me learn that
Hanako(x, y); ∂(fox)/∂x
As I said, this is a pretty fundamental concept, especially in high school :)
that was what you were doing earlier with the multiplication
yeah now i know what im doing more
yeah
If you learn vectord without learning what displacement, velocity and acceleration are, you are missing out.
Oh any one more thing, about acceleration:
Acceleration is how fast the speed is changing.
Imagine a car travelling at 10km/h, 20km/h then 30km/h, and so on so forth.
You can see the car's speed is increasing.
yeah
So we say that the acceleration is how fast the velocity vector is.
Anyway you won't be using acceleration a lot, it is mostly used in physics and mechanics, but it is still good to know.
I don't think I've ever seen much acceleration vector questions
alright but i dont think its gonna be accelerationin the exam
Yea, fair enough
Yep, velocity and displacement 👍
No problemo
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✅ Original question: #help-23 message
@noble mango i got a question
What's up
could you also just turn those velocity vectors into displacement or nah
Ah yes that's also wanted to say
So
Let me ask you this
If a car is travelling at a speed of 50km/h,
How far does it travel after x hours?
it dependso n the hours
100 km
How about 10 hrs?
500 km
Consider how you got these answers
50x = 500
Eh well
Drop the equal sign
So like,
After x hours, would you agree the car travels 50x km?
yeah
Good so
It is possible to turn velocitt vectors into displacement vectors, but there's a small caveat.
Actually there's two:
The first one is exemplified here
If you don't know the actual time, you will need to have a variable next to it
So in this case, the variable is x
This is pretty useful if you are given questions where the time is unknown.
The second one is that you will also need to factor in the starting position
This is not so much a problem with vector questions
But just to illustrate what I mean,
If you have that a plane starts at (0, 100) and is travelling with velocity (10, 0),
Then to write the vector of that plane, you'd need to write it as:
(0, 100) + (10, 0)x
But this I am guessing is a little too advanced
yeah
So don't worry about this for now
This one is the important one I would say to remember.
Just as an example,
what if i were to just multiply those velocity vectors into displacement
How would you turn the velocity vector of (1, 2) given that some particle is travelling for 3 hrs under this vector?
by 0.5
3x1 and 3x2
This works too! But there problem is a small conceptual note you have to take in mind
Just to clarify,
It is easier to turn displacement into velocity
Than it is to turn velocity into displacement.
why
This will be explained a little more once you go to calculus
alright
In displacement, you need a starting position, right?
yeah
oh so if i dont have a starting position i cant
(Constant) velocity vectors don't need a starting velocity
All of these problems assume constant velocity
Displacement vectors do need a starting position though.
yeah
In calculus, we call this an 'initial condition'.
nice name
wait
what if instead of the time
which is 0.5 we had the distance
i can do distance x speed
then it gives me displacement aswell?
Not so unfortunately
Because distance * speed is not displacement
oh alright
Displacement is distance with direction
If you want to be technical about it
Its actually
distance * (vector with distance)
For example,
If I travelled 10 units in the direction (1, 2), what is my displacement?
(10,20)
Actually did a bad example because the distance of this vector is not 10 😭
Its technically
(10, 20)/sqrt(1 + 4)
oh nah
Because you have to turn (1, 2) into a unit vector
Yeah dw about that if you havent seen it lol
yeah 😭
Oh forces
scalar product
You might learn it soon actually
like 210 N and one person pulls it
Sounds like an actual vectors course
and it tells me to find the vectical force
Yeaaah
like physics
Anyways if your teacher hasnt covered it, then you probably dont need to know it. But you should eventually stumble across it in your math study of vectors.
Vectors are pretty pretty important
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