#help-4
1 messages · Page 4 of 1
mathematicians respond to this by defining a different kind of lowest and highest
they are called "infimum" and "supremum" which in this case is the 0 and 1 you expect
always nice when you talk about sequential compactness and your limit is actually in the set though
as richard feynman once said Mathematicians can do what they want to do, one should not criticise them because they are not slaves to physics
I regard mathematics as a higher form of thinking as compared to physics
physics also doesnt need to care about indivisible quantities when they act vague about the radius of a particle, or that forces never seem to end but only diminish in size across large distances, or that the planck length and such are commonly defined because "our math cannot accurately support what the world may do at these scales," or...
do you want to hear the proper way to show that the function is discontinuous
physics is not mathematics and mathematics is not physics
Lets not get there
Let's talk bit more about "they don't even know what's pi value" (no ill intended )
I know it already.
At a point of discontinuity of a function, any two of the left hand limit, right hand limit and the functional value do not match.
how is a limit defined?
It is the expected value of the function at a point
E[f(x)]
we assume a small interval near a point and check the functional values in this interval.
"let him cook"
we then make a prediction about the expected value at the point by assuming that the function will not behave in an unexpected manner and that it will keep on behaving in a predictable manner in this small interval
@pine prairie
okay this is nonsensical
we have very rigorous definitions of continuity in math because it works for our purposes
trying to reimagine the definition will lead to lots of issues because there's a reason why everyone's settled on the standard definition of continuity
I am defining the limit
every other definition will cause some issue here or there
It will behave at the centre of the interval as it does on the edges of the interval.
other problems include:
- it can be too similar to the current definitions so you dont gain any new information
- it's too unwieldy to work with for most cases, so not many insights can be gathered
@pine prairie what is your definition of limit?
I did ask about the proper way instead of any new way, do you know what the proper way is?
it begins with "e"
there are 2 main ways to define the limit, in open sets and as a metric
Please teach me
there we go
for your purposes i believe a metric definition will be sufficient (the open sets one is more general)
Formally, we'd start with let $(M, d)$ be a metric space, this means we need to be able to measure distances in $M$, informally, we can just consider the real numbers $\mathbb R$ and the distance between two points $a$ and $b$ to be $|a-b|$ using the absolute value function
frosst
A function $f$ is said to be continuous at $a$ and equal to $L$ if for all $\varepsilon > 0$, there exists a $\delta > 0$ such that $|x-a|<\delta \implies |f(x) - L|<\varepsilon$
frosst
that's what one calls the "epsilon-delta" definition of continuity
one sees this usually in first year of university
occasionally its also taught in around 11th to 12th grade if your math class is forward enough
thats around when I learned this definition of continuity
I have read this definition
I got a picture
but I haven't got examples to solve using this definition so
you might as well practice on one
I use my definition for solving problems
your definition may not align with the definition they want you to use
It works well enough, although I face troubles visualising using that
its not exactly a strong definition, thats the definition most people use
it's very scary to imagine things in maths, because what you imagine may not be the same thing as what others are imagining
you might as well accustom yourself to the epsilon-delta definition since thats most likely what they'll want going into university
to imagine something is to assume you know all there is about it
proofs avoid this pitfall
here go practice on a limit:
I'll have to understand this epsilon delta definition
@pine prairie how would you define the limit?
the limit was already defined as shown
i would define limits using open sets because that's the most general definition of continuity that i know of
but for your case they are equivalent
The epsilon delta definition defines continuity, doesn't it?
it does
Can you please teach me the proper definition of limit?
i just did
I can show you a way to understand how to use it
i would argue that sequential limit is far easier to understand than epsilon delta
perhaps you should start from there
that is true, I forgot about that definition
part of the usefulness of epsilon-delta is that there are other ways that act the exact same way as epsilon-delta
i rather like the decreasing epsilon and increasing N, the constrast makes it easier to grasp imo
How can I use this definition to solve some problems?
Do you have a pdf on hand that I may go and solve?
show that x^2 is continuous at 0 and is equal to 0
Please share the solution as well, so that I can understand the definition
you can also search up "epsilon-delta proofs" to see more examples
if you want I can show you an easier limit and how it would be solved
Sorry a bit off topic but I need a movie on this channel conversation
doesnt seem angry or eventful enough to require one
there are worse ones
this just seems reasonable
@pine prairie how would you argue that
https://www.youtube.com/watch?v=kVQNhAIFZYc this video looks pretty good
We introduce the epsilon delta definition of the limit of a function. We will explain the definition of a functional limit in depth, see some visualizations of it, discuss the negation of the definition of a limit, and then complete two epsilon-delta limit proofs for practice. #realanalysis
0:00 - Intro
0:59 - Epsilon Delta Definition of Limit...
i just skimmed it but it looks like they go through the ideas well
the greatest integer function(thanks for sharing the video link) is continuous at non integral points?
We look at the graph(which is a series of steps), and consider one step and leave it's integer to the side, we get an open interval.
How should I argue that the function is continuous in this open interval...?
you should get a good sense of epsilon-delta before trying to attack this problem
your function is in fact very easy to show continuity even
Please show me how to do it
the fact that constant functions are continuous is very easily shown
you should watch the video first otherwise you won't understand what im saying even if i write you a proof
you just need a sense, it wont require much work as soon as you get the sense
Please do, even if I have to do more work in the end
you might as well consider the work of watching the video
watch the video first
this isnt a movie, youll have to sludge through the entire video but its a necessary pain we have to go through
one of the benefits for a commonly accepted definition is that there's videos and explanations for epsilon-delta everywhere if you search for them, we showed you an example up there
sure, but I cant guarantee Ill be up to answer questions
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right
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given a unit circle, consider a convex polygon which contains the unit circle, if the area of the polygon is A, what is the maximum possible perimeter? if there is no maximum possible perimeter, what is the supremum possible perimeter
i am basing this off a question i have seen earlier which showed if a convex polygon has area A and perimeter P, then there exists a circle of radius A/P completely inside the polygon, the proof involves drawing rectangles of width A/P on each side of the polygon
if that helps
Hey anyone wants to work with me on a theory that explores symetries and prime numbers?
wrong place to ask
do you mean one that is contained within the unit circle?
otherwise i could just make a very large square
could you direct me?
I do not have access.
the area is fixed, its A
ah
so one thing is its upper bounded by 2A i think
suppose the sides are s_i, distances from centre of circle to the sides be d_i then
A=sum of 1/2(s_i)(d_i) and P = sum of s_i
now d_i>=1 gives P<=2A
you have bounded area
hm
how did you prove d_i >= 1, i know it make sense, but idk how to prove it
it contains the unit circle so d_i has to be more than radius=1
uh but if you take an equilateral triangle of area A
well, if convex was not there i culd give you a counter example
oh frick
it is that thing multiplied by root(A)
so you have to divide this thing by root(A) to get the answer
minimum value of A in which this works is
P/A is exactly 2 in this case
oh nice
for minimum A
not for all A
only for one particular value of A
also, we havent proven di >= 1
the circle is inside it
so every d_i will exceed radius
is that not a satisfactory argument
no
why
ik, but how would we prove it?
oh i proved it, assume such a line exists, then all other points must be on one side of that line, but the circle must be completedly contained in the convex hull of all points, this is a contradiction
oh yes
this actually solves the qn for areas under 3root(3)
because for that i could just make a shape always tangent to the circle
so we have A<=3root(3) P_max = 2A
but what about for A higher then 3 root(3)
oh this is wrong
i cant always make a shape tangetnt to the circle
for A <= 3root(3)
i can do it for A higher then 3 root(3) though
how?
just by shifting one line slightly
oh actually i can do it for A lower then 3root(3) as well
i can just consider a n sided regular polygon
and i can shift the sides smoothly
hm
so we have a maximum of 2A for all A > pi
what about this, interms of A and P, what is the maximum size of circle we can fit into any convex polygon with area A and perimeter P
it works if you consider an equilateral triangle i think
.
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If the D of a quadratic eqn is D > 0 and not perfect square then roots are irrational and occur in conjugate pair similarly for D < 0 roots imaginary and occur in conjugate pair. What makes them occur in conjugate pair? why
if D is negative it's in the form of u ± iv for u, v real
these are by definition a conjugate pair
you can prove a more general result concerning complex roots: for a polynomial of any degree with real coefficients, all its roots are either real themselves, or come in conjugate pairs
How do i come to know any random polynomial has the roots your talking about
basically prove this: for a polynomial P with real coefficients, if some complex number z is a root of P i.e. P(z)=0 then z* will also be a root
this can be proved via $P(\overline{z})=\overline{P(z)}$
Ann
z* is another new root?
Ok
i usually write conjugate with overline but it is not plain text friendly
Kk
i do not want to repeat the same things many times
Mb
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Can anyone solve this for me
All multiple choice questions
this isnt a feeding answers/crunching problems server, you can ask to be explained a fundamental concept that may apply to a wider section. Read #info
@hearty garnet we're not chegg
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What is the definition of intramolecular forces and intermolecular forces
intramolecular: forces within molecules
intermolecular: forces between molecules
Google it lmao next time
intra- means inside ie within one thing
inter- means between things
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Can someone explain to me why for a) you use the numerator and for c) you use the denominator??
Other way round even
But u know what I mean
do u guys learn about difference equations in math?
Your answer for c is wrong so
,w (3 ln x-7)/(ln x-2), x=1
Its not
Whoever made it is a muppet then
Yup
Wait but they're getting rid of the denominator
That's the thing
They're only looking at the top part
So 3lna - 7 > 0
So it is right
????
And when ln a - 2 is negative?
Then you’re multiplying both sides by a negative quantity but not flipping the direction
Look at what I sent above

Hmm
For part a they use the denominator to deduce k
And here the numerator so like what idk
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Wait u are right lol can u explain what I would do then
Consider what you can multiply by for this to not be an issue
Alternatively use some common sense to determine when a quotient is positive
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The Golden Gate Bridge is an iconic structure spanning the neck of San Francisco Bay, connecting the city of San Francisco at the northern tip of the San Francisco Peninsula with Marin County near the town of Sausalito in the south. The spans of the bridge are 1,280 meters, and the towers are 230 meters above the water. The cables between the towers are in the shape of a parabola. The parabola is located in the Oxy coordinate system as shown in the figure, with the vertex of the parabola coinciding with the center of the road. Point A on the parabola is shown in the figure. Find the height of the cable at a position 200 meters from the towers (round the result to the nearest unit).
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
The Golden Gate Bridge is an iconic structure spanning the neck of San Francisco Bay, connecting the city of San Francisco at the northern tip of the San Francisco Peninsula with Marin County near the town of Sausalito in the south. The spans of the bridge are 1,280 meters, and the towers are 230 meters above the water. The cables between the towers are in the shape of a parabola. The parabola is located in the Oxy coordinate system as shown in the figure, with the vertex of the parabola coinciding with the center of the road. Point A on the parabola is shown in the figure. Find the height of the cable at a position 200 meters from the towers (round the result to the nearest unit).
Well, it's a long text, for these, the best thing is to just take the minute and quickly read through it
In the end, all that is needed is the diagram
There might still be some additional info that is relevant, which is not really the case here
i dont know how to find the height
Can you mark the position that you want the height of
(Just approximately)
you could try to sketch it in a more clean place aswell, might help u see points
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In case that there is a Vector-space, with the dot product $\langle\cdot,\cdot\rangle$. For all subspaces $U,W\subseteq V$, the direct sum $U+W$ is defined as.
$[U+W={u+w|u\in U,w\in W}]$
how can I show, that $V=U+U^\bot$?
McMake
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In case that there is a Vector-space, with the dot product $\langle\cdot,\cdot\rangle$. For all subspaces $U,W\subseteq V$, the direct sum $U+W$ is defined as.
$U+W={u+w|u\in U,w\in W}$
how can I show, that $V=U+U^\bot$?
McMake
there we go
Good job
ty
I can't help you though, bcz i can't make a head or tail out of it 😅
OoO, that's what i thoughhhh
Well thats not the definition of direct sum
ive translated from german. im sorry if some terms are incorrect
V is a direct sum of U and W if V= U + W and U intersection W = {0}
its the case in the end of the qeustion anyway, since I am using the orthogonal complement
Yes
but ty
Okay so you want to show that for any vector $v \in V$, we have $v = u + u'$ where $u \in U$ and $u' \in U^{\bot}$
Herbert
What have you tried?
ive tried showing that via orthogonal projection, but I cannot finish the calculation
since $\langle v-u,u\rangle=\langle v,u\rangle-\langle u,u\rangle$ but that doesn't get me to anything
McMake
Okay, so I would try taking a specific basis for U and U^{\bot}, and showing that their union is a basis for V and so we get our result (since you say you have shown U intersection U^{\bot} = {0})
u
uhh
how do I make a basis out of both, that fulfills that definition?
i haven't done anything like that before
Do you know gram schimdt orthogonalisation?
yes
Ok, so take an orthonormal basis for U, say ${e_1,e_2,...,e_n}$ and define the projection onto U $\pi : V \rightarrow V$ by $$\pi(v) = \sum_{i=1}^{n}\langle v,e_i\rangle$$
Then any vector $v = \pi(v)+ (v-\pi(v))$. Then if you show $\pi(v) \in U$ and $v-\pi(v) \in U^{\bot}$, you are done
Herbert

this only gives one point and makes me concerned for my future
I thank you very much
i think that works
.close
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Yes, but i hope you showed it
"it"?
I mean the statement that pi(v) in U and v - pi(v) in U^{\bot}
(To complete the proof)
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Can anyone help me? I have dyscalculia and have been stuck on this one problem for a few days because i dont really understand the material
!da2a
No need to ask “Can I ask…?” or “Does anyone know about…?”—it’s faster for everyone if you just ask your question! See https://dontasktoask.com/
I guess im just not sure how to differentiate? can someone explain the difference to me?
I read the material provided but it didnt really make sense to me, is their a simpler way this could be explained to me?
Every "rule" im given to find the difference seems to also apply to the other 2???
any help is appreciated
do you know what a derivative is?
Yes, i do however have a math disability that makes this super hard for me
I know its a dumb question
no it's alright
it's not a dumb question
okay, lets start with putting the question into our own words to understand better
alright
could you repeat to me, in your own words, what the question is
Well theres 3 curves that are showing the motion of a particle along a coordinate axis at t (which i think is seconds) They are all polynomials and related, but i need to pick drag S(t) and A(t) and V(t) to their respective graph lines
Its just that the rules to differentiate them make no sense to me
ahh I see
It refers to hills and valleys like they all dont have that
your understanding of the question is fantastic
Thank you
do you know what a derivative is?
Im very rusty on this so im a little foggy on how to find them without power rule or like L'Hopitals
alright
Thats what i thought!
This question actually tests your understanding of polynomial functions and their graphs more than your physics or calculus knowledge
Ok I need an understanding too
the acceleration graph should not be a line
Hint: the position function is actually a polynomial to the fourth power
Position function Can't be to an even power but yes any odd power
I assumed the parabola was the s(t) but a friend said i was incorrect
?
what are you talking about?
your friend is right
I thought so…
Oh so any higher odd power polynomial can look like cubic function am I right?
If thats not the position function then im not sure how to tell which of the other 2 is? what am i looking for?
Remember my hint
Nvm
remeber that the power rule is that d/dx ( x^n) = nx^(n-1)
so by that logic s(t) would be the solid line?
Wait no
The dotted one i think
that's beyond the scope of this question. Maybe some series expansion of odd power functions could approximates a cubic near 0, but I'm not sure.
👍
I'm assuming you mean the round dot line
👍
with your help i think i got it
not quite
MANNN
very close
remeber that d/dx (x^n) = nx^(n-1)
each derivative decreases the power by 1
Im writing this down hold on
Hint: odd functions can be negative, even functions can't (unless it has a negative coeffiecient)
I have one more of these left , lemme try to use that rule
@broken orchid the little irregular change in gradient of dotted graph indicates it maybe with highest degree or is there any other logic?
I think i did it right this time
note that the general shape of a polynomial function will adopt the shape of the highest power polynomial as abs(x) increases. It is not possible of a O(x^2 ) function to have such a bump becuase all x^2 functions can be factored into y = a(x-b)^2 + c
not quite
actually, every answer is wrong
REALLY??
trying is what matters
is a(t) represented by the straight Line? i thought about that
I think the real problem is that you don't have a solid understanding of how polynomial functions can be graphed
Is very hard to explain anything like this to me in a way where i understand, Dyscalculia is a horrible thing to have
Im really trying to get the rules
indeed
Maybe he first needs to know how position, velocity and acceleration correspond to each other and then with help of derivatives question can be crack
I think we should start from the basics of polynomials
There are a few rules about polynomials that will help you deduce the answer:
even power polynomials will only trend towards one infinity as x increases or decreases
okay..
odd power polynomials will always trend towards both infinities as x increase or decrease (the particular positive or negative slope isn't import in this case)
Arent they all trending towards infinity?
polynomial functions to the second power will always be a bumpless parabola as all functions of x^2 can be repersented as a(x-b)^2+c
by both infinities, I mean positive and negative infinity
by one infinity, I mean only positive or only negative infinity
second power meaning a(t)?
second power meaning any polynomial functions of the form ax^2+bx+c
where the highest power is 2
Can you explain this in laymens terms? i have no idea
you know what the general form of a polynomial function is yeah?
Not sure how to type it but vaguely
a polynomial function of the second power, is that but the highest power is 2
Alright
Ket me see if i can apply this to something rq
So a(t) is most often represented as a straight line correct?
I might be confusing it with v(t)
This is so confusing man
yes and no
oh?
given that you have three lines, s(t) v(t) a(t)
the lines v(t) a(t) are most likely to be lines, if your teacher isn't devious with making the questions
however, all three lines could be straight
if your teacher is a devious person
However, this does not mean that it is like for v(t) and a(t) to be lines.
like with the first example, all three could be curvy
alright, I have to go now
there should be other people here to help you, @ the helpers if no one comes for a while
<@&286206848099549185> I need help, i dont know how to do graphing questions and im not sure how to continue
ok, ask on.
so, you want to mark the main details
asymptotes, extremum
whatever they asked
Kinda? i have a bunch of questions i dont know how to answer, i understand derivatives when used numerically, but graphically i just dont get it
Like this for example, if this was not a graph question i could work it out but Derivatives of graph lines just dont make sense
This was an easy one i actually knew how to answer but you get the gist
I tried using the x-x/y-y rule but i dont think im doing it right
I followed the tan line to choose a point but im not sure how to determine WHICH point i should use
Does it matter?
<@&286206848099549185> The answer is 1 right? Partner is telling me its 2
no rules.
oh alr
1.5 to 2
use a compass.
just hard done practice.
Wait which point was i supposed to use??
i knew (-1,-1) but the other?
x=-1
for each x theres one y.
i dont know. i didnt use a compass
just practice parabolas.
Not sure how to work out when the point is at the peak?
f'(x)=0
meaning, the slope is 0!
you can see here, x=-1
and y=3
max {-1,3}
thats how you write it.
mb
y= -(x + 1/2)² - 3/4
y' = -2(x + 1/2)
So yes it's 1
no, x=-1±1
hm?
im so lost
because we already know that f'(-1)=0
you go right and left to it
x=5.31 isnt nice
go for x=5
or x=-10
those are nice numbers.
choose an x, nice to work with, smaller than -1.
maybe, -2
maybe -10
then use -2
you wont put there a million, bc thats too big
its dumb
I though to find deriv, i needed to use the tan line?
so go close
is it desmos?
geogebra?
i dont know those systems
i work on paper
Stupid ass site called "knewton" i had to pay to use
YOU PAID?
god damn bro.
Yep,
god save you lol
Im really trying man
I just dont know how to find the deriv of this, im trying but everyone is telling me different things
ok, so theres a formula
a general formula
f(x)=ax^b
you know this form?
2x^2, 5x^4, 3x^2.5
yes
in this case, the derivative is
f'(x)=ab x^(b-1)
@green shore just ask for practice anytime
sorry, trying to work this one out
the skills you really want, are quadratic formula
basic algebra (dont need to know 7^7, its useless)
Im using a weird formula
mx+d=ax^2+bx+c?
no a fraction one
huh.
this one i believe
I have dyscalcula man, they all genuinely look the same to me
I have trouble telling the difference
i dont remember formulas
i remember how to do it
its muscle memoru
i dont know the formula, it takes a lot of thinking for me
use markers.
i just.. dont know how to do this, and eveyones using these big math words and formulas i dont understand
I have a math disability man, and this is very tough for me
im trying to use this
anyone here know autocad?
What's that?
!occupied
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thank you
@green shore you know the function of the curve given?
sadly no, only the curve
Ok so can you plot any desired straight line on the graph
I have to move the black point wheres its deriv is 5
i know the problem
i had equations longer than the width of the page
the solution, mark in colors
It's impossible to do it manually either you have to have an equation of curve or be able to draw a line with slope 5 so you can drag the point and make parallel to it
hahaha autodesk. i hate autocad.
solidworks>autocad
Do you know how to find the downward angle of G using polar coordinates?
Dude, all I’m given is this graph and the question of which point makes the derivative equal to five
360-alpha
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Is kicad open source version?
That's what I tried
theres freecad, freescad too.
what can i do?
solidworks is.
But I did 360-alpha
But my drawing is wrong
im the god of 3d modelling, not 2d
Isn't it basically 270+25?
but for 2d i know of freecad, freescad, kicad
i have like 500 to 900 hours modelling
295deg?
and algebra, 2000 hours
the calculation is
wait what
I genuinely think my help session got hijacked
it was.
Yea 115-90
want in dms?
Cause the given inside angle is 115
Why?
not yours.
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Oh is this help channel?
For the 3rd time!!!! @halcyon lintel
I thought it was main chat
for specifically little e
no, no you have to go to the other chat to ask for help
ask on little one
There’s a bunch of ones on top they should say available
My bad...I don't know why i auto joined this room
i can handle 10 people too
Can you help in dm
yes
K let's do it
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mate just post the question(s) you need help with
dont beat around the bush
yes we can help you
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how to simplify this imaginary number :
(cosθ + isinθ)/(cosθ - isinθ)
multiply the denominator and numerator by the conjugate
i tried and i got some expression but i can't tell if it's correct or not
show your work
thats correct
there's no more simplified expression of it then?
nope i don't..
Herbert
do you know any identity for cos 2\theta?
well you need to know atleast one identity for cos 2theta and sin 2theta
i see
do you know any identity for sin (a+b) and cos(a+b)?
nope either 😅
okay then this is as much as you can simplify it
Have you considered writing in exponential form?
no i didn't
do i need to?
Do you know it?
do you know exponential form?
It'll help with the simplification.
yeah
okay then write them in exponential form
re^iarg right?
Oh, great! Try to write it in exponential, then.
okay
hello guys I apologize for the suddent cry for help
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I'm sorry I'm kinda new to the this discord channel but I'm kinda missing the help channel even after following the steps do you mind pushing me in the right direction
basically I can't do step number 1
i ended up with e^iθ
Show your work.
ohh wait i made a mistake
ill do it again and send u the pic
sorry id I'm taking too long
Ok.
,rccw
Good.
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ello
i need to find the derivative of sqrt 2x
using the limit definition ?
or power rule
First, you can recognize that $\sqrt{2x} = \sqrt[2]{2x} = (2x)^\frac12$.
@tepid wind
From here, it becomes easy to apply the Power Rule of Differentiation.
and i keep getting 1/sqrt x
Can you show your work?
You can't change $(2x)^\frac12 \implies 2x^\frac12$.
@tepid wind
what happend to the sqrt2 ?
,, (2x)^\frac{1}{2} = \sqrt{2} \cdot x^\frac{1}{2}
<rajel />
it should be $\frac{\sqrt{2}}{2\sqrt{x}}$
<rajel />
i don’t see it
wdym ?
,, \frac{\dd}{\dd{x}} \left(\sqrt{x}\right) = \frac{1}{2\sqrt{x}}
<rajel />
you dont need chain rule?
you do
,, \frac{\dd}{\dd{x}}f(x)^n = n\cdot \frac{\dd}{\dd{x}}(f(x))\cdot f(x)^{n-1}
<rajel />
you can apply the same thing for: $\frac{\dd}{\dd{x}} x^{\frac{1}{2}}$
wtf\
<rajel />
my teacher has legit taught "the power jumps down and leaves behind one less than itself"
well thats true , *for simple functions *
i.e for any x^n
but it doesnt work here?
but based off of this alone can you not find it?
<rajel />
it works without adding the derivative because its just 1
but for any other function it wouldnt
how is it just one
its 2x
wouldnt it be 2?
thats because of the constant
the constant doesnt matter when its about derivating , we keep it aside and we work with main function
i.e the result would be multiplied by that constant
,, \frac{\dd}{\dd{x}}(3x^3) = 3 \cdot \frac{\dd}{\dd{x}}(x^3)
<rajel />
it is 1 , but became 2 cuz of the constant
just try to derivate it and you'll get what im saying
i got it
but like how are you supposed to do that only knowing that na^(n-1)
because when you blindly apply that you get smth weird
I know but thats the only context she gave us
see what im saying?
anyways
ty
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Given a point P and a line r in space, with P not on r. How many lines in space pass through P and are perpendicular to r?
in 2d it's quite easy, it's a unique line
in 3d when looking for orthogonal lines we do cross product, with the lines' directional vectors
so it should be infinitely many lines?
if the lines dont intersect with the line r
idk tbh
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How do i solve this question? Investigate graphically and show with a simple sketch whether there any v such that 2sin(v+12°) = cos(v+23°) for 0° < v < 180°
I put it into geogebra but i don't know how to make the x axis into degrees
do you know how to convert radians to degrees?
yes 180/pi
in the geogebra keyboard there should be a degrees symbol somewhere
(although all the degrees symbol does is multiply by 180/pi)
you can just plot your bounds as well
since 0 deg = 0 rad and 180 deg = pi rad
you can plot x = 0 and x = pi
and see if there are any intersections between the two vertical lines
like this?
yes
so now we can tell if there are any intersection points within the given bounds
so the answer would be 0.211*(180/pi)
yes, 0.211 * 180/pi degrees
or just 0.211 radians
although if you're rounding it should be 0.212
alright thank you very much!
yup ill fix
have a nice day
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where do i start
look where the tangent line changes from above the curve to below the curve or the other way around
i think im dumb
happens
just that i dont know what your talking about
you don’t know what a tangent line is?
like graph of a tangent or slope of a tangent line thing?>
no like literally a tangent line
when the line changes from above —> below or below —> above you have a point of inflection
i think im just dumb
um like plat to diamond
you
i started in like 2016
yea i played in 2015
but like played fr during 2020-2021
i played here and there from 2015-2019
ive just been on and off
didnt pay that much attention
yea idc
not quite
any of them right?
basically it’ll look like a line when there’s a point of inflection
looks like x = -0.5 and x = 1.5 to me
oh its where it turns from one concave to the opposite pretty much
yea
i feel stupid
happens
i litterally didnt understand
where oit changes from concave up to down
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Asked this earlier. Had to leave
"Check that the following implicitly defined function are solutions of the corresponding differential equations"
Solving a)
I'm not sure what it is I'm supposed to do. Do I find the derivative for the implicit solution?
a) is not homogeneous. I've checked
i mean you can literally just find dy/dx
from implicit differentiation
you need to verify that
$\dv{y}{x} = \frac{-2xy}{x^2 + 2y}$
knief
which follows immediately basically
what don’t you understand
hm
"A relationship G(x,y) is an implicit solution of an ODE F(x,y,y',...y^(n)) = 0 with x in I if phi exists such that G(x,phi) = 0 and F(x,phi,phi',...,phi^(n)) = 0"
so phi is x^2y + y^2 - c = 0?
plus c i guess if it's just a constant
F(x,y) = 2xydx + (x^2*2y)dy
this makes it all over complicated tbh
maybe
you have the relation x^2y + y^2 = c
you need to show that you get 2xy dx + (x^2 + 2y)dy = 0
so just differentiate both sides
in relation to what?
i mean i don’t think it matters?
if you assume y is a function of x it works
if you assume they’re both functions of something like t it’s fine too
not sure how rigorous this needs to be
its the second exercise in the first ODE exercise guide
probably not too rigorous
@frozen ledge
this okay?
yea
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you’re welcome
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is this correct?
also small mistake at the start i just saw it should just be r not r^2
im mostly asking about the integer, cause idk if its the correct one
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does anybody know how to do quadratic regression with the T1-84 Plus calculator?
stat -> calc -> 5: QuadReg
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Hi
I need the formula for the perfect square trinomial
<@&286206848099549185>
<@&268886789983436800>
@safe fulcrum
@subtle crane dont ping individuals or mods for math help
@subtle crane Has your question been resolved?
Could you give me a picture?
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how do u do this
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Ann Gets Rekt By 8th Grade Geometry: Part 3
all given info is on the picture. my progress is basically just working out the lengths i marked. and i worked out that angle PAB is 54°. but once again ive hit a big fucking snag.
well like also AD=a if it matters at all lmao
and DAP is 90°
and ADM is isosceles
but idk how that helps either
wait if ABCD is a parallelogram then AB=CD no?
how is it AB=2DC
2BC. typo
o
yeah this
god thats a normal 8th grade problem?
it feels like it would help to draw AM and MB. and then maybe something with AMBP ? but I dont know
ann you are not alone
I suppose AD and BC are parallel to each other because BAD and ABP are alternate interior angles, arent they?
its a parallelogram
The helper gets helped 🗣️🗣️🗣️
Fr
Not throwing shade btw
ikr i dont think an eight grade even knows what a bisector is
I think they would
not like you need that word
🇧🇬
Bulgaria was one of my least expected countries with school curiculum as tough as that
Oh wow
yeah ngl i am actually hardcore skillissueing at this problem
like ive even given it to a colleague and she can't solve it
fun times!!!!!!!!!!!! (not)
maybe its about 36 54 90 triangle properties? its not an exact match but in simple physics you just assume triangle's lengths are 3k 4k 5k
????
no
that's pretty wrong mate
a 3-4-5 triangle does NOT have angles 36 and 54 degrees
i can tell you for a fact this ain't it
i might be remembering wrong my bad
a more accurare diagram might help?
I drew it on a paper geometrically accurate


