#help-39
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omggg
Circular reasoning
Premium trying to help
Goodnight fellas šāāļø
Am a g not a b
Goodnight fellettes
Good night man
Did you figure out why itās Tā(t)/|T(t)|
Also I lowkey am confused on the difference between what direction a particle is going and how its turning š
They kinda seem like the same thing
This is so cooked bro
<@&286206848099549185> anyone please?
Thanks bro
You are stuck on the second oneās intuition I take it?
@sweet schooner
Just #1?
Thanks man
So for the first, the tangent. This is essentially a particle moving along the curve and you can see what the speed and direction is of that particle. So it gives the direction of the curve, and the slope of the point
The unit tangent, however is basically the same thing except we donāt really know what the speed is (we lose the slope) so we really only see the āorientationā or direction
So for the tangent unit vector , we are considering the direction of the velocity , correct ?
Pretty much
Okay but
Only the direction at a given point
Does the direction of the velocity always follow the path of the position function?
Yes it does. Because we parameterized it and itās a smooth vector curve š
So how come when you graph velocity it looks so different
?
It looks like a whole new curve
Or am I understanding it wrong
Well it should be. The position function and velocity function, while one is the derivative of the other, are two completely different functions
And may not look similar at all in most cases
So if they donāt look alike how can you say that the velocity has the same direction as the position function? Is that not related to the tracing of the curve ?
Well positionās direction really only tells you where you are from the origin
The velocity (tangent) shows you what direction you really are moving
What Iām saying is
for that should the trace from r(t_0) to r(t1) look the same as the velocity from rā(t_0) to r(t1)
Not at all
Arenāt the velocity vectors supposed to be tangent to the entire curve tho
Maybe the length would be different
So thatās why
Wait so here the graphs would look alike?
No not necessarily
The idea is that on a position curve, each point (probably will) have a different direction and magnitude
When you apply the tangent
But I thought the velocity would follow the same direction
Ah! No. Only at a given point do you get the velocity. The position curve doesnāt really give you any immediate information about the direction
Oh
So we canāt identify the direction at which the particle moves just by looking at the position curve r(t)?
Correct
Thatās why we need the tangent
I mean technically you can, but for all intents and purposes, you cannot
So whenever Iām looking at a velocity function, can I confidently say that the trace of that velocity function is the true direction the particle is traveling in
Not necessarily, the trace is how the velocity is moving over time
the velocity function will only tell you what the velocity is at a given point, and how THAT curve moves is the ādirectionā
I will draw a picture
Say this is your position curve. It just shows you where a particle is
T(s) measures your velocity at a point
Basically the velocity curve will encode the information of ALL T(s) at a point into a given graph
So neither graphs can give you an idea of the direction the particle is moving in?
The velocity graph pretty much does
But you said it doesnāt necessarily
Well think about a typical position vs time graph. if you graph the velocity vs time graph, do you really see exactly the direction? Maybe you do
I donāt personally. I just see how it changes
Look what I really do know is that the tangent vector to the position graph is the value of how instant the position is changing with respect to time
But only at a point like I could imagine a bunch of tangent vectors
Do parametric equations follow the same logic?
Because I was gonna say letās consider f(x) = x^2 and fā(x) = 2x
To make it easier to talk about
I was about to give that example
If I take the derivative at some time Iām gonna get a tangent line
Thatās the instantaneous rate of change at that point
Now what do we know here?
Correct. Itās analogous, and exactly the same idea, to the same principle but applied to a parameterized curve
Okay so
Looking at the parabola
Can you say that the U shape is the direction of the particle
No you canāt right, because if we graph 2x, we see that the direction is negative for x<0
Okay isnāt U how the particle is physically changing positions tho
Like the U shape
So why canāt I say that from the fist end of the U shape to the second end is the direction the particle moved
Like it went dow down down then bottom then up up up
You can, thats basically what youāre doing. However, when you say down, itās moving in a negative direction right?
Yes
When you work in higher dimensions, that isnāt enough to characterize the movement per say
You can extend the argument, but then the velocity graph will have that information in it
Okay so regarding that
For each time t, the instantaneous rate of change will yield a tangent line right
Yes
So that tangent line tells us what? Where the particle moves physically and its speed?
The direction it is moving in*
A bit of nuance in that, but it doesnāt tell you where it is going to be at, but where it is going
Think of the U shape again, the direction of the tangent at the bottom horizontal, however, it is goes up again
Same idea
Okay there are two things I wanted to ask
If the tangent lines are hugging the curve
Why is its graph a line
Thatās the first question which basically concerns derivative functions having different shapes although their tangent lines are almost hugging the original curve
Well, it is in the case of our parabola because the derivative is a line. For our curve, whatever it may be, it will probably be a curve as well
Sorry but why is it a line as in
What really does dictate the shape of the velocity graph ?
If Iām being honest itās just the function as a result of the derivative
Okay forget that, if we wanna examine direction of where the particle is going, (because this concerns the original question about unit tangent vector) does the entirety of the velocity graph show us that? Or only at one point? Is it even valid to say that the velocity graph shows us the direction the particle is moving in?
Yes so, the velocity graph will take the information of our tangent at EVERY point.
And the velocity graph doesnāt necessarily show you āvisuallyā but say the velocity graph takes on a coordinate at (-x,y,-z) then we know that the position function at those coordinates is moving in the negative x and z direction and positive y direction
Interesting
And for that logic we utilize the unit tangent vector ?
Essentially, yes
Okay now what about the unit normal vector ?
And what do we mean when we say it represents the turning of the particle ?
Whatās turning here as being different than direction ?
Itās pretty much only encodes just the direction (or turning) we have no sense of magnitude about the āspeedā
Because we normalized it and made it a unit vector
Hey man, I have an analysis exam tomorrow. I need to get some shut eye. If you want I can continue this tomorrow
No worries man get some rest
Thanks a lot
@south ice Has your question been resolved?
@south ice Has your question been resolved?
@south ice i can try to help you... but i wanna understand the peculiar point of misconception u r facing?
@south ice Has your question been resolved?
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Hi for this gradient, do you only look at the m?
Its my tutor's writing ^^
Ah okay thank youu
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How can I approach this problem?
my first instinct was integration by parts, let u =4x^5 and dv = e^-x^3 but i started integrating the dv and i realized you cant really do that so im kinda stumped... My next idea would be to let e^-x^3 be u so i can differentiate it and do it that way around but i dont really know how that'll play out so i figured i'd jsut ask.
ok so it should turn out like 4/-3integral(4te^t)dt cause the x^2 cancels with the -3x^2?
i think
yup
i didnt get the splitting the x^5 factor thats so random
from there i think i can handle the rest
you can rewrite x^5 as x^3 times x^2 substitute it cleanly
The trick is trying a u-sub with whatever's in the e^(). You'll see that a lot
do u have any tips for spotting this / name i can write down so i can remember that double usubs like this exist?
o
And if not the e^(), then the ā or the ln()
so problems with e^n^x just try to get rid of n^x with a sub first and simplify
Even more general than that! See an e^()? Consider the sub.
alright ill write it down for sure
i dont wanna get caught on the midterm with a question like this and its just a simple trick like that before it becomes solveable
ty
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how do they take a moment about X?
X is just floating bruh
how they know these distances aswell?
@blissful brook Has your question been resolved?
Indeed you need those distances. Question seems borked
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Using theta and 2a you know those distances @blissful brook
yeah i see it now
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I'm fully stuck actually
The diagram I drew isn't to scale(the angles are only approximately correct)
apparently staring into a white abyss doesn't gift me any answers
wait so let me clarify: angle AOC is 43 degrees and angle APC is 18 degrees? And youāre trying to find angle BOD?
yup
i think its an intersecting chord theorem
huh never heard of that, lemme look it up rq
isnt that for intersection within the circle?
yea
it is that
wtf ive never heard of this formula
i do think this is outside the syllabus of the paper ive yoinked this from, is there another way to solve it?
is line ad a straight line
If AOD and COB were a straight line it could never converge
because then you'd have diametres
That being said, singularly they could be but I don't see a reason why they should be diametres
nop
Me too š I've done barely any geometry in high school
yer it sucks shouldnt be too much of a problem if its not in syllabus
ok but hear me out it kinda looks like that āangles in the the same segmentā property so rn im just staring at it waiting for an epiphany to happen
you mean "Angles subtended by a chord of one length are always equal"?
the one from this picture
oh yeah that
I don't know how that would help then
yeah iām stuck too but let me think about it for some time
idk i guess i have like no intuition for geometry, but acc to this, you'd have 7 degrees? that feels wrong
7 degrees? whereād that come from?
from that formula
might want to check your reasoning thereā¦i donāt think the formula was applied correctly
? a is 43, b is x and c is 18
no?
so $43-x = 36 \Rightarrow x = 7?$
Supernova
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help?
yea
where does the 4 come from?
260 / 65 = 4.
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ā Original question: #help-39 message
why do i minus 260 by 260?
To get a 0
to get a 0 as remainder
why not 26 by 26?
26 is not a multiple of 65
why are trying to see how many times 65 "fits in" 26. Its clear that this is less than 1. We then try how many times 65 fits in 260. this is 4 (since 65*4=260) so we then know that 65 fits 0.4 times in 26 since 260 = 26*10
normally, when doing long division, you want to subtract an integer multiple of the divisor.
unfortunately, 26 < 65, and while 26 can be kind of nicely expressed as a fractional multiple of 65 (26 = 0.4 x 65), long division does not deal with subtracting fractional multiples of the divisor.
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Can someone help me with one specific topic first? I want to understand how to derive the pmf of Y=g(X) when (X) is discrete, using the CDF method. Could someone explain it first intuitively, then practically with the formulas and a simple example?
For example, if Y = X^2, could someone first explain intuitively what is happening, and then show the practical method step by step with the formulas?
Actually
I want to start with transformations of random variables, meaning Y=g(X), and understand intuitively what the transformed random variable actually is before moving on to CDF, pmf, and pdf. Could someone explain it first in a simple intuitive way, and then with a basic example?
<@&286206848099549185>
@green aurora Has your question been resolved?
@green aurora
Is a function
In that case, doing Y = g(X) is just function composition
Okay
Help pls
Can someone help me with one specific topic first? I want to understand how to derive the pmf of Y=g(X) when (X) is discrete, using the CDF method. Could someone explain it first intuitively, then practically with the formulas and a simple example?
You donāt have to repeat your message itās ok
The pmf of Y is P(Y = y)
For that, you look at all the values x where g(x) = y
And then you sum over the probabilities
So sum_{x such that g(x) = y} P(X = x)
this is the line of possible values āāof X
if you choose for example x = 0.15 in that case
the transformation says like: āok, then the new value is y=x^2"
@sonic patrol is this what you were saying?
it's related yes
but why is the blue arrow pointing towards the green dot?
you'd have to ask alee
@green berry
its (0.15,0.15^2)
the blue arrow means I take the value of X and bring it onto the graph of the function y = x^2
it means the transformed value is y = g(x) = x^2 , so I sign it on the Y-value line
so the yellow dot on the line is the value of the new variable Y
taking other values āāon the line of possible values āāof X you get other possible values āāof Y
well it doesn't have to be, it depends on the range of values that X takes
or because must g(X) be invertible?
Let me add that the same interval of X does not always become the same interval in Y
for example in this case if we choose values of x close to 0, y changes a little while close to 1 if we change a little x, y changes more
So the function can compress or expand the pieces of the axis
So when you look at these intervals of x and y you have to think that the transformation changes the "geometry" of the values, and therefore also changes the distribution
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I have no clue how to calculate standard deviation here
For mean i have 1550
They just want a formula
Var(X) = E(x^2) - E(X)^2
Really?
Where E is the expectation, so E(X) = sum x / n
We never learned such a formula š
Let me think if I can relate it a bit closer to the sums
Oh wait im dumb i didnt read the book
Oh cool!
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<@&268886789983436800>
Hello?
what is 6+7
21
you should ban @grim anchor
Too hard
and $\infty$ years of ban
1 divided by 0 equals Infinity
already closed
Ah lol
give him a timeout or smth
minimodding 
poor me can't apply for mods just because im a minor š„
10 didvide by 4
blud
help me
how old are you?
14
and you still need help with 10/4?
60/1000
he is tryna not get banned or stuff lowk āļø
he's still surviving
i need help
what do you need help with
he's trolling and the channel's closed
100/ 1589
oh izzit, damn i didnt notice
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Is there a function that has a derivative only on all irrational numbers?
$\pi x$
MarcoMa210
guess what the derivative is
on all irrational numbers
ah
this is surely non trivial
(and nowhere else)
f(x) hits all irrationals and nowhere else?
f(x) has a derivative at all irrational number points
what is the question
Is there a function that has a derivative only on all irrational numbers?
you could use the fact that the irrationals are uncountable and thus are a larger set than the rationals
build the derivative off of that and then get its antiderivative
I guess yes
why
let me think a example
but then again the function $\pi x$ is rational at $x=\frac{1}{\pi}$
what
to get a function that hits only the irrationals it would have to be discontinuous
MarcoMa210
thats not what im asking
that's an example
you can look for Thomae function
its continous
not derivable
the Thomae function is not differentiable at any point
what about Weierstrass function
you are asking for a function whose derivative does that
make a function such that its derivative is the thomae function
This can be a situation seen in specially structured functions that violate the rules of continuity and differentiability.
your question isnt like that
(accidentally left off part 2, which is the part you need)
it seems to be true for D(f) as well, but I can't find a definitive answer either way, still hopefully this is a starting point
I'm trying to help, but it's very difficult to convey what I'm thinking because it's not my native language Im so sorry ıf I understand you all badly
ah yea, i think this does what you need: https://math.stackexchange.com/a/106397
you can let G_1 be the irrationals and G_2 be the empty set
oh wait, you want it differentiable on the irrationals, not non-differentiable
ah yeah differentiable
you can swap the roles then
well not exactly swap
you can let G_1 = empty set and G_2 = rationals
oh yeah that would do
cool, both work (can be differentiable precisely on the rationals, or precisely on the irrationals)
i don't think i knew this until now
interesting
i suspect it's highly nontrivial to prove it in the generality above, maybe there's a shortcut for the irrationals specifically
idk it was just a question that popped up in my head xd
thank you very much tho
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yw, cool question
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is this the correct way to think about this exercise or am I missing smth?
I would do the number of pins (10^4) - forbidden by considering each possible position of 73 (3) x the permutations of them (10^2), so yours reads correctly
Ah yes minus the overlap
I would've missed that
it is correct
yes
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help why for (i) is it x > 0 and not x greater than or equal to 0???
Where does it say x can't be negative
it doesn't say x can be negative
but why is it only x > 0
should it not be including as well?
Can I ask a physics related question?
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Does it need to be?
for how can it be greater than equal AND equal when x is only greater than 0
i think so
Why
So?
so it doesnt make snese
Why does e^x need to equal x+1
so it can satisfy the inequality
otherwise it would just be e^x > x + 1
yes i believe so
Why
correct me if im wrong
š
You're wrong about something, but you're avoiding my question so I can't correct you
because tangent means it only grazes on point of the cruve
so only at one point are the two functions equal
and that is point (0,1)
the y-intercept
And what does that have to do with x>0 implies e^x >= 1+x
i think the statement is completely false becuase e^x = 1 + x would only be true if x were ever equal to 0 but since it's only greater than, then therefore it should only be e^x > 1 + x
Yea that's incorrect logic
but then that would not make sense or help us at all because our end goal is to use squeeze theorem
how is that incorrect
what how?
It is also correct to say 4 > 3
Do you know in English words what the symbol means
no
$\ge$
only greater than or less than
riemann
Greater than or equal to
is it the "or"
Is 4 equal to 3? No
Is 4 greater than 3? Yes
Therefore 4 is greater than or equal to 3
ohhh
its like ||
ah i see your point
let me consolidate this once more
ok so you're implying it could hold true if x > 0 and also x >= 0 right?
it really just depends on what you need then right?
yeah i get that now
ok thanks @plush bramble and @plush basin i appreciate your help
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yo chat I need help I wasn't here for class on this day what I do, I do NOT know what I'm looking at rn š
@dusky gulch Has your question been resolved?
Functions gr 11 MCR3U1
I do
but im still cofnused
idk
Which ones don't you know
then, for future helpers, please explain where you're stuck and what you've tried (since you said you do know at least some of them).
can u help me with the other images the blanks aren't as important
idk what to do on the other images
Can you tell me Y in terms of X for Example 1?
That would be the answer for (b)
it says y = x^2
Its says f(x) = x^2
where
i only see y = f(x) and y = x^2
oh nvm I see f(x) = x^2
but how the heck do I graph that
Using this can you tell me y
for the table of values?
does that say y - 3f or y = 3f
=
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So f(- 1/2 (x+1)) = (- 1/2 (x+1))^2
@dusky gulch
ā Original question: #help-39 message
We don't know what y is yet
i couldve worded that better mb
we need to figure it out using that equation
but it says y = 3f[-1/2(x+1)] - 4
why did u plug in the equation into f(x)
when you say f(- 1/2 (x+1)) = (- 1/2 (x+1))^2
the (-1/2(x+1)) part equals x?
but how does it equal x
Do you understand functional notation?
yeah I know how that works but
Functions are like a inout-ouput things, if u say f(x)=x³ then then u can substitute x with anything u wany like x+3, x+4 and so on
Input*
Because that is how functions work
The definition f(x) = x^2 is defining a behaviour
Using x doesn't mean anything, it's a temporary variable used to represent this behaviour
It would be the same function if i wrote f(P) = P^2
ohh okay
but
why did u just plug the part in the brackets
wait
why didn't you do f(3f(- 1/2 (x+1))-4 = (3f(- 1/2 (x+1))-4^2
instead of just f(- 1/2 (x+1)) = (- 1/2 (x+1))^2
*why did you leave out the 3f & -4
OH
so basically it's saying take the value of f from the second equation and plug it into the first?
so like if u get smth like this again u should plug this into..
this
am I on the right track now
@full wadi would that be what I write in b or a?
(b)
what do I write in a then?
or do I write that later
because I didn't sketch the graph yet
why is it even at (a) then
Using your table (the one u deleted) name the transformations happening in that equation for y
So I would state the transformations for this?
Yes, state the transformations happening to f(x)
Including what is happening on the interior, so what it means to go from x to -1/2(x+1) in the function
what about the a and c value
What a and c values
can u word this simpler š
You can post that table again so I can see what you're seeing
so nvm
because the equation is y = af[k(x-d)] + c
format
So name the transformations that correspond to a, k, d and c
the table doesn't say anything important it's just the basics of knowing transformations in equations
Why doesnt it just say state the transformations of y = 3f(-1/2(x+1))-4 then
but it says state the transformations applied to the graph y = x^2 to OBTAIN y = 3f(-1/2(x+1))-4
Because y is a transformation of f
And f(x) = x^2
So y is a transformation of x^2 graphically
so saying that wouldn't the new equation be y = 3f[-1/2(x+1)]^2 - 4
They're saying imagine you had an old graph showing y = x^2 and now you have a new graph showing this, how was this old graph transformed into the new
i still dont get it, should this be important to know?
If I take y = x^2 and transform it to y = (x+1)^2, what is that called?
It should be in your table
arent u just inputting a value as x which is x+1 in that case?
Look at the third row
d = -1 so a horizontal shift to the left by 1 unit?
Now apply that sort of logic to the rest of the values
The way u worded it was uh different ig, why didn't you just say state the transformations of y = x^2 to y = (x+1)^2
I think when you said "what is it called" got me confused
Sorry about that
Can you also tell me why the horizontal stretch by a factor of 2 is 2 and not -1/2 when k = -1/2 and not k = 2
The - doesn't effect the stretching amount
is it because it's 1/k
basically
cant u sya
say*
Horizontal stretch by factor of 1/2
then
okay so it must be the denominator always
It is just 1/k (positive)
U see where it says -1/2 and the fill in the blank page says
k < 0 = graph is reflected in the y-axis
k > 1 = graph is horizontally COMPRESSED
0 < k < 1 = graph is stretched horizontally
(in all of them it says "by a factor of 1/k")
the equation says y = 3f(-1/2(x+1))-4
k = -1/2
bring back "by a factor of 1/k"
we have 2 as k, isn't that greater than 1 (obviously), so why is the transformation stretched and not compressed
when the denominator only matters
nvm I thought about it
the -1/2 tells you that it is stretched but then the 1/k (k = the factor)
so if I had 3 it would be compressed by a factor of 3 right?
thanks
and just to clarify again the - in the -1/2 doesnt matter right?
The -'ve means it was reflected
But the stretching factor is positive
Actually reading what they say it should be by a factor of 1/3
But I agree that it makes sense to say it was 'compressed' by a factor of 3
As here you say they all say a factor of 1/k
negative or positive = reflection or no reflection
so which is right?
either one?
Use what they say
I don't know how leniant your markers are, hopefully not š
so can the new equation be f(-1/2(x+1)) = (-1/2(x+1))^2 OR y = 3(-1/2(x+1))^-4 are they both right?
They new equation is the y one
so when you said
If I take y = x^2 and transform it to y = (x+1)^2, what is that called?
the y = (x+1)^2 is the new equation
right
and if I add the f in the new equation is that fine
(and still able to simplify it into vertex form)
what do I do for the right of the table of values
i already did the left part
but idk what to do on the second table of values
the top section would be your new equation for y
yeah I figured that what about the x and the y
oh
like why is there underscores there
wth
Im not sure
im guessing it doesn't mean anything then
You can put your answer in (b) next to the y
As the left table has the original y = x^2
The top section should be in terms of f
wdym in terms of f
do I have to simplify to vertex
This is your new equation
but with ^2 right
<@&286206848099549185> I need to do something can someone take over ā¤ļø
what is 'the above relation'
We need the relationship
y = 3f(1/2(x+1))^2 - 4
Okay so just map ordinary points and plug them into that
Plug x=0 into that equation and then whatever value you get that is the y value
Do that for 0,1,2,3 etc
replace x in the relation with the x values from the other table ?
@dusky gulch I think what you need to do is
1.just write the relationship that you have got , by solving the main problem , in the uppermost rectangle
2. Write values of x like -3 , -2 ,-1 below x ( as same in the left table )
3. Write values for y besides it that you get by putting x
ik now so on the right table the first value under x would be -3 and then i would plug -3 into the relation i have in the uppermost rectangle and that would be my first y value
Yeah
first one is -3 and -1
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I think I made some mistakes
Can someone help me pls
<@&286206848099549185>
Sorry, ik I am not suppose to ping right away, but I am in a rush
1st one correct
(16) seems good, maybe you should say you slowed down as you approached it
but write slow down before stop
not go up down hill here but go back to the start place would be more concise
since distance increase decrease
go away from home then walk back home for instance
You could say you were running back and forth between two points
slowing down to turn as you reach the ends
but what do the curly lines represent?
turning back
This would fit
alright, thanks guys
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How do you have 3 channels h
idk
two different h
h
h
h^3
are you sure the y axis shows distance?
idk
that's why I am stuck

oops, speed i mean
did the question say that y-axis is supposed to be speed?
it looks like you can name the axes to be anything
I thought it was arbitrary
show question gng
whats arbitrary
yeah
pick a random
2nd question lookin weird today
oh
or pick any
so the second one can be: running back and forth from two places? @trail minnow@sterile python@iron basin@full wadi
depends which place you start
y axis is speed or distance?
speed
.
what terms did you learn for now?
as in distance, displacement, speed..
that seems wrong
are you just allowed to name the axes anything?
you're speed increases and decreases with respect to time?
so it's distance?
most likely
yes it tells me to write a possible situation for that graph
but i think the graph shld be diff might js be me
the first one could be current vs time
or speed whatever
current?? where did I come from
Da river
wha
since we can name the axes anything as long as the graph matches
@cerulean dome Just use this
Make sure you include that you start at some distance away
Because the graph doesn't start at 0
its for the charging of a capacitor a saturation curve dont think too much if its out of your scope for now
y distance x time, right?
Actually you get to choose
ok š me dum dum
im not saying you're dumb bruh im js throwing ideasš„
if you could specify it as "distance from a point" then sure
!done
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whats with the gifs
distance normally signifies "distance travelled"
its .close
.close
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wha
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324630 mod 99
basically the reminder when 324630 is divided by 99
324630=99 x 3268 +98
so remainder seems like 98?
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that x-a x-b kinda threw me off
what was that?
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Hii i still don't quite understand how to draw the graphs thing?
Is it when its x² its a U shape on the graph?
Take the "U" with a pinch of salt, but yeah
well kinda
Ph okayy
big U
So if its x²-2x+1 what would it be, im still confused š š
And whats the equation for the n shape?
You should start doing a bit of algebraic manipulation for those.
These kind of equations "ax^2 + bx + c" are called quadratic.
And there are multiple ways to express them.
try plugging in x values (which returns a y values) and see what happens
Uh, so if its x=y² its n shaped?
Ou okk thankss
err no
Wdym by plugging in?
y = ax^2 + bx + c
Is both an equation, and what we sometimes call a "function"
If you choose some value x, then you can calculate its corresponding value y.
You previously mentioned: x^2-2x+1
Say we choose x = 2, we will get 2^2 - 2*2 + 1 = 1
So its located in y?
for n shapes do you know how to do reflection
So, when x = 2, y = 1 > which you can plot like in a map
No
do you know how to flip a graph
Ouhh okok thans
Never heard of it :'
Its a vertical but slightly tilted line?
okay well to flip a graph it is to flip the sign of a
where ax^2 + bx + c
So if a is + it becomes -?
yes
Ouhh
Okk
notice how only the x values change on the points but not the y values on the points
this is called reflection across the x axis
yes
I saw someone say this is y=x²-2x+1
Does the 2x not matter? Bc the graph didn't go to 2x jere? Just 1
Hi
It does matter, yes.
The 2x is the cause of why its shifted to the right
You should probably learn vertex form and root solution methods.
Oh!
Since the 2x is negative you flip it so it becomes positive 2x that's why its moved to the right?
Yes but it face upward, if -x^2 face downward
Its quite more elaborate than that.
Oh ;-;
Ouh okay thankss
To clarify, if you write down the equation as $y = ax^2 + bx + c$
The value a tells you where the parabola points and how stretched is.
b vaguely tells you about the shift to the left or right
and c tells you the shift up and down.
Thing is, b doesnt only move the parabola left or right, it also displaces it up and down too.
So theres a specific balance between b and c if you want to keep it at the "normal height" of the the vertex touching the y = 0 line.
For vertical shifts, a and b don't change, only c does
to be honest c do the most in shifting up and down
and to left write just add to x
you can complete the square for horizontal shifts
and tweak the x term
inside square
For clarification, b does move the vertex of the parabola up and down tracing a parabola itself.
C simply moves it up and down alone. > Which is what we formally know as a vertical shift.
@ashen slate Has your question been resolved?
Oh!
So c does up & down & b does left & right?
Oug okkk thanksss
no
depends on c, shift of x
š ok then uhh
So if i want the parabola to go to the left i put lets say $x^2+3x+1$? Is it possible?
Mugnes
Oh ok thank yiuu
Ah
nah you got to use y = a(x-h)^2 +c
where h is shifting horizontally
If i want to move the parabola more to the right do i just change the c & keep the 2 the same
you use that formula when completing the square
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No
Oh
Ah ok9k
Oh okay thank youuu
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The question asks you to carefully sketch the graph. I know that by definition of this function, the absolute maximum must be at tau=0.
What can I try to do?
youve gotta make the exact graph?
I note that for tau to -infinity and infinity the function tends to 0
no
rough sketch?
the trend of the graph
alr
correct
now try finding some roots
put the above trig fxns to zero
and see if something works out
hey is there a specific name for this function
autocorrelation function
It's not defined at 0 btw
but it doesn't always have the same expression
what field is this used in?
but autocorrelation function has maximum in 0
I mean there will be a division by 0
The limit as tau->0 may exist but I'm just saying you need to indicate that the function itself is not defined at 0
ok
given that the function as tau tends to -inf and +inf tends to 0, can I say that it is not periodic?
I just need to know if the function is always positive or not
parthisjoking
,rccw
that does not matter that the first term is indeterminant
the other two will outweigh it
mostly
but by any chance is the function asymptotic to -B^2 sin(4\pif_0tau)/(512\pi^3f0^4tau^3)?
I don't understand how you figured out how much the left and right limits were
in 0
@green aurora Has your question been resolved?
but since the maximum is in 0, shouldn't the limit in 0 be finite?
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hey
hello
how are u
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where is the mistake
Why do you assume there is a mistake?
so it's commutativ3
Is it? Math isn't a guessing game!!!
i luv helpers having fun while helping