#help-27
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@crystal lava do u have the correct answer available
this would give u about 9.6 and 24.6 which is indeed wrong
@crystal lava actually what u gonna do is equate this quadratic to 180
AHh i think what is wrong
[x^2+15x-236=180]
first apply the alternate segment theorem
I think the angle 236-15x is this one?
yes
maybe
u see that angle
So this is wrong
You want to find angle beta
Then beta = 180 - alpha
then beta = x^2 by subtending same arc
just go for beta=x^2 then apply adjacent angles sum = 180
yea solve this
7 and 8
Looking good
There we go!
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Blud why are you named like ts
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guess a root
try x=-1
well, here x=-1 is a solution right?
then you can do division
divide that cubic by x+1
to get a quadratic
i feel like a clerk atp 🥀💔
I think you should tell him why guessing the root was useful in this case
It's the first thing to do when solving cubic, or any equation tbh
Guessing some roots like try 0,-1,1,2,-2
The roots have sums of -6 and product of -6, which combined with the fact 1+2+3=1×2×3=6, a guess would be the roots are -1,-2 and -3
Of course a way that doesn't depend on knowing niche facts would be try plugging in values, once you know one root you can do polynomial division to get a quadratic
or this, rational root theorem
what if the cubic has complex or imaginary roots ? would you still guess ?
wait
irratonal roots too
We don't know if it has complex roots or not, guessing or rational root theorem is just a way to find potential rational root
if the root is not nice you cannot guess, its like trial and error for ugly roots you cant find by trivial methods
i get it
you would need numerical methods
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Cubic formulas 😂
,w cubic formula
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for complex roots you can check the derivate sometimes
if its complex you know you already fucked up
tbh you would not get such cases
just use desmos lowk
we can use cuss words in this server ? 😭
ye dont be homophobic tho
politically neutral ones
bet
brother knows from personal experience
ok guys this channel is closed we should move
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well i dunno about any specific thing i can invoke
like
any property
what property should i use
a proof by contradiction definitely comes to mind
but what is the contradiction am i looking for?
like i said i can't think of any property that would do the job here
Idk if you learned some derivatives yet
i do know derivatives
Maybe analyse the difference between consecutive terms
There's a property that squares like 1, 4, 9,... have a difference that differs by 2
1, 4, 9, 16
Differences are 3, 5, 7 that differs by 2
Not to interrupt, but I think a proof would be if you have an arithmetic sequence with common difference d, you can prove that two consecutive numbers a and a+1 have a difference greater than d
?
yeah i think the contradiction gotta be to show that the sequence is bounded when it cannot be
this is the way
1 25 49 have a common difference of d so you have the right idea but need to flesh out the end of the proof
it's not quite "prove that two consecutive numbers a and a+1 have a difference greater than d" but similar
If the difference in 2 consecutive squares is greater than the common difference, the sequence can no longer have a next term after that point
But like the squares could be anything
the contradiction is constructing an infinite progression from a finite set
true
Not just consecutive
how do i do that-
his point is the difference between consecutive squares goes to infinity
how
Consecutive would be the best proof I think. Because everything after that has a greater difference
so the difference between any 2 squares will eventually be larger than d
Ah i see now
let's start by saying the series is
x1^2, x2^2, x3^2, xn^2
then our difference is xn+1^2 - xn^2 = d
now what?
difference of squares?
yeaa
ok great so we have
(xn+1 - xn)(xn+1 + xn) = d
what does that tell you about
xn+1 - xn and xn+1 + xn
in relation to d
the common difference
your difference is going to be [
x_{n+1}^2 - x_n^2 = d \Implies (x_{n+1}-x_n)(x_{n+1}+x_n) = d
]
You may consider the smallest possible difference you could have with something like [
x_{n+1} - x_n \ge 1
]
both are like factors of d
yea
i dont know any number with infinite factors
uhm how do i get that conclusionn
no we wrote xn+1^2 - xn^2 = d
both are like factors of d
you know xn+1 + xn and xn+1 - xn are factors of d
and we ASSUME that it is possible to have an infinite arithmetic progression
this implies xn goes on infinitely
so xn+1 + xn and xn+1 - xn being factors of d, where xn infinitely goes on... that would mean d has an infinite number of factors
which is a CONTRADICTION
no integer has an infinite number of integer factors
so you're saying if we make xn infinitely large?
thats how like we're gonna reach the conclusion?
xn as in the terms of the progression
it's an infinite progression so there is no end to the xn's we have
lets say n starts at 0 with x0
the progression is x0^2, x1^2, x2^2... xn^2
n -> infinity
yeah yeah i gotchaa
since its being added
its TOOOOOOOOOO
big
so like
d cannot exist
blah
no
you dont understand what you concluded yourself
please try to repeat the argument i tried to present
okay so like
what im understanding is
if we take the common difference for xn^2 and xn-1^2
and then like factor it
so
diff of squares yes
what is infinite, exactly?
n
n itself is not infinity but there are an infinite number of n's in the progression
likewise xn
(xn + xn-1)
(xn - xn-1)
what is infinite?
no like i said n itself is not infinity, nor is xn or xn-1
like you need to separate the concept of infinity and infinites
n is a placeholder number okay
infinity is not a number
there are an infinite number of n's we have in the progression
in other words there are an infinite number of xn's
and xn-1
so, how many xn + xn-1 are there
and how many xn - xn-1 are there
well an infinite number of those?
yes exactly
but hold on...
you claimed earlier that the product of these two is d the common difference
d is a finite integer that is fixed and does not change with the progression
so technically, you just said this integer d has an infinite number of potential factor pairs
is that possible?
no
great so thats the contradiction
in our original assumption that there does exist such a progression, we found an impossible conclusion
hence our original assumption must be false and this progression cannot exist
but we'll have to assume that d is not zero for that rite?
oh wait yeah
its distinct
i see so like that removes the case that
the factor pairs are equal
which is not possible
meaning all of them are factors
i dont quite understand what you mean by that
was simply stating the obvious that d must not be zero lol
but like thats a given
sorry for the wait was playing a bit around with the factorst trying to see if theres more to be said
theres finite factors to extract from d but you need infinite of them to get infinite xn's to sustain the progression
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now prove that the longest progression can be at most 3 integers!
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Hi, I am in the midst of a Textile project & I've run into some 3d geometry problems for some of the shapes that I need to cut out of cloth. Currently there are 6 different pieces & for the life of me I cannot understand how to get the area equations for the indivudual pieces.
The larger eclipse section of the object is sort of shaped like a football, with one tip of the triangle ending in a equilateral triangle that is B length on each side
5 & 6 are half circles, I drew them that way just because its something cosmetic I am going to do later in the project
@cosmic lance Has your question been resolved?
Is the larger eclipse section you're talking about 1?
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piece 4 is simple, it's just 11 sqin
piece 2 & 3 can be found from the overlap of two square functions, which from desmos approximations, i got as:
\left(x+2.6\right)^{2}+\left(y-1.5\right)^{2}=15
\left(x-2.6\right)^{2}+\left(y-1.5\right)^{2}=15
(image 1)
so, we just need to find the overlapping area of these circles exclusively for where y is positive. we can instead flip the vars x and y and integrate only the +ve area of the \left(x-2.6\right)^{2}+\left(y-1.5\right)^{2}=15 equation which can now be converted into a function, then we integrate from 0 to the intersect points of the plane and then double it.
so now our challege becomes to find the area under the graph of the function \left(y+2.6\right)^{2}+\left(x-1.5\right)^{2}=15
using the circular segment formula, i'm not pasting my math here cause i wrote it down, but it's just plugging in the values gives an area of ~4.76 square units, or, 2x for the piece an area of ~9.52sq units.
for pieces 5 and 6, it looks like what you're trying to say(I THINK) is that the half circumference is 1/2 C or 11/2=5.5, so we'll just operate with r=5.5/pi
area is just \pi\left(\frac{5.5}{\pi}\right)^{2} or approx 9.68 sq. units
and i'm not sure what piece 1 is.. is it two overlapping elipses?
2:9.52
3:9.52
4:9.68
5:9.68
@cosmic lance can you elaborate?
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yes
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Its the larger section of 1
?
Replying to a previous question it seems
Piece 1 is the entire bottom side, its 2 overlapping eclipses
i see
that help channel is already closed
you can tag them in #math-discussion if you would like to continue it further
I was busy then, would you like me to restart the entire thing in an entire new thread?
^^
I have a solution for everything but piece 1
To find the actual area equation to be able to draw piece 1
Hi, I am in the midst of a Textile project & I've run into some 3d geometry problems for some of the shapes that I need to cut out of cloth. Currently there are 6 different pieces & for the life of me I cannot understand how to get the area equations for the indivudual pieces.
(not my doubt, anthropdics)
The larger eclipse section of the object is sort of shaped like a football, with one tip of the triangle ending in a equilateral triangle that is B length on each side
.
.pin
The eclipses overlap by a length the B variable
Is there any way you could paste the math you had for the overlapping eclipses (Piece 1)?
& for more context, 2 & 3 connect to the lowest point of the large eclipse in piece 1, so then 2 & 3 will end at the intersection of the eclipses to form an equilateral triangle
In 3 dimentional space
@cosmic lance Has your question been resolved?
Heres a sort of 3d version of what I mean
@cosmic lance Has your question been resolved?
@cosmic lance Has your question been resolved?
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Q 7
did you answer my last q
like what shape do all the points equidistant from AB and CD make
Idk
Straight line ?
close
well if it was a straight line how would you identify that straight line
does the angle bisector at O work
Didn't get u
No I can't do that
answer this. it will clear things
u sure?
If I bisect xy at o then how will it be equidistant ?
well take a point on this bisector
and drop the two perpendiculars onto AB and CD
any congruent tringles?
I didn't get ur point
draw the angle bisector at O
take a point on it
actually which part did u not follow
And label it xy ?
sure
Why so ?
whats the distance of a point from a line?
its the length of the perpendicular from that point to the line
Yes
thats why we drop the two perpendiculars to see if they are equal
But wont it make whole lime equidistant then ,
Should I have chose o itself ?
choose an arbitrary point on the bisector
Ya I did that only
But u said wrong
yeah but which point did u choose
Upper portion
its not clear to me cus u circled one point and drew lines onto another
alright
<@&268886789983436800>
<@&268886789983436800>
bruh
Wt happened y u called nods ?
scammer
mb
Who scammed ?
u missed it
I changed 8t now
share
any congruent triangles?
There is 1 common side
yah
2 90 degree
ya
I don't see anything else common
well remember what XY is
yessss
Ya so perpendicular of equak length
yeah
But wt does this mean with q ?
you tell me what it has to do
think about it
That particular point is equidistant
well every point on the angle bisector
Yes
what about the intersection of the angle bisector and XY (our given line)
But we jst needed 2 points 8ght ?
Didn't understand
we have AB and CD
we have somerandom XY
and we have the angle bisector of AB and CD
Yed
the angle bisector and XY can intersect at some point P
no xy is arbitrary
i mean in ur drawing u labelled the bisector as XY
but im talking of XY in the question
But when I shared pic u didn't say that
the name doesnt matter
just forget everything and use this naming convention
now we label the intersection of XY and the angle bisector as P
does this help
green is the bisector
Yes
so P satisfies the condition in the question right
So how did I take perpendicular fro her ?
Yes
Isn't the whole line p equidistant ?
p is a point
So is somewhere right side ? Bw c and b
So by that I proved 2 equidistant points
So that's it done ?
But how do uk that xy comes there onl y
yeah done
i dont understand
@zealous bronze Has your question been resolved?
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Kinda confused on ii and iv
what in particular is confusing you?
kinda the wording
ik thats vague
so for ii
if theres twice as many moniters ig we could start with y < 2z ?
that's a good start
i meant to put as with eqaul to aswell but my kb doesnt have that
but idk sometimes i find it confusing and it feels like im just guessing icl
let's just use <= and >= for equal
okay
the way i think about ii, there are two parts:
- at most tells me the type of inequality
- twice as many monitors as mice tells me what the terms are
so if we said "there are twice as many monitors as mice" that would mean 2y = z
okay okay, so i understand the first point, its the second one whihc i find more confusing
so is it kinda thinking about it oppositely - ik that sound wierd
yeah the multiplication by 2 does kind of apply to the opposite one
yeah i see when u think about it, it does acc make sense
so twice as many monitors as mice means that you would have to multiply the number of mice by 2 to match the number of monitors
yeah yeah
hm
i see
i feel like i understand that part now
how about part iv, im more confused on that 😭
iv is similar to ii but the multiplications happen on both sides
hmm
so like could we just go straight into saying that 3x = 2z
then we see at least so then its 3x >= 2z ?
acc no
it would be more moniters
so 3x =< 2z ?
yeah
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hint #1: tartaglia's triangle = pascal's triangle
hint #2: this is an identity.
it's not
it is isn’t it?
just because is a triangle is not pascals
Look at Pascals triangle: What does each entry actually mean in Pascals triangle in terms of combinatorics.
Then. look at how you would get that element
If not then define what Tartaglia's Triangle is, because Pascal's Triangle is also called Tartaglia's Triangle.
regardless, they use the same symbol as n choose k
so it probably is pascal’s
I guess i was mistaken
all good
I still don't know how to solve the Q
so what do you know about pascal’s triangle
the way it’s usually defined is that the sum of two entries next to one another gives the entry below it
how?
So do you see the 10?
it’s the sum of the 6 and 4 above it
and it’s the same for all entries
what about it
that’s how the triangle is defined
have you encountered these symbols at all before?
wdym
what about the 1 at the top
like have you heard of pascal’s triangle, binomial coefficients, or n choose k at all? it just seems about strange question to give without some introduction beforehand
oh the ones on the side are kinda defined to be there
If you have 1 thing, how many ways can you choose 1 thing from that set of 1 thing?
then it’s the sum rule
well it’s 0 choose 0
but I don’t think they’ve seen that
ye
what about them
how
I can explain but I need to know where you heard of them from
since there’s about a bajillion ways to interpret them
in class
lol
I mean like did you just hear the name or was it defined a certain way
okay I’m just going to go with the combinatorial definition: these numbers are the number of ways to pick k things from n things
for example how many ways are there to pick 2 numbers out of 1, 2, 3, 4?
4 c 2
how
so that’s essentially what this question is asking
here’s a hypothetical:
suppose you knew all of the ways you could pick k things from n things but now you need to find the number of ways to pick k things from n+1 things
so I might list all the ways to pick 2 things out of 4, but what if I wanted to find the number of ways to pick 2 things out of 5 using that information?
same thing
nCr if there is no restriction right?
uh this is a help channel but no 5C2 ≠ 4C2
ik
I’m trying to build a recursive formula
uh huh i see
idk
4 c 2 + 5 c 1
not this either
4 c 2 + 4 c 3
5 c 2 = 4 c 2 + ?
how many ways are there to pick 2 total things out of five if I don’t pick 1 vs if I do pick 1?
|AnB| = |A| - |AnB^c|
uh let’s think about it for this example first
we don’t really need to think about the most general structure of the problem
4C2 vs 5 C 2
so if I do pick the 1, think about how I’ve already completed the action of picking it
so I picked one
now I have one more to pick
so how many ways would that be?
w what
can you explain the 5 C 2 part?
o o o o o
^5 marbles to pick 2 from.
I can take the first one
o o o o
o
Now there are 4 marbles left and 1 to pick from: 4C1
if I make sure I don’t pick the first one and I throw it away
o o o o
I still have to pick 2 from the 4 remaining so 4C2
what if I had n marbles and had to pick k
how does that generalize here
n c k = (n - 1) c (k-1) + (n-1) c k
yes exactly
now how is that related to this
we had 5 c 2
where did the marble went
wdym
you mean in the bottom?
it’s gone, reduced to atoms
that’s the case where I didn’t pick the first one
wdym
what you answered the question earlier
like if I wanted to pick 2 things
I could either take the first marble or not take it
you got this right? are you unclear how you got there?
yes
but how
well if I had n things and wanted to pick k, I can divide it into 2 cases:
I pick the first item
I don’t pick the first item
If I pick the first item, it drops into my inventory. how many remaining items are there and how many do I need to pick from them?
4c1
what if you dont
in general, this is (n-1)C(k-1)
look here. the situation does change if I choose not to take it
if I force myself not to take it, it’s exactly the same as if I yeeted it into the sun
so the situation is like either I pick the starting marble or one of the others
regardless you always set some marble asside
kind of, maybe I should rephrase.
the starting marble will be part of the group I pick
the starting marble will not be part of the group I pick
yes this is a good way to think about it
you’re making a decision about it either way
what group
how?
how what?
does this make sense?
no
did this make sense?
no
did anything make sense 😭
no
I guess you have to make a decision on whether to take each marble or leave it
and since we made a decision for the first marble, that leaves 4 more marbles to make decisions on
maybe my explanation style doesn’t work for you (which is totally okay). would you prefer to wait for someone else?
you have to pick 2 marbles out of 5
you have to grab 2 marbles at the end of the day
suppose you grab a random marble from the 5 you have
you set it aside, and now there's 4 marbles to pick from
the marble you initially picked either is the one you wanted or it isn't
suppose the marble is the what you wanted then you have 1 marble more to pick from the 4 marbles left
suppose the marble isn't the one you wanted then you have 4 more marbles left and you still need to pick 2
what do you mean elaborate you explained it correctly
forget it
what 😭
is fine I think I got it
okay then lol
ah okay
do you understand this formula now?
n c k = n - 1 c k - 1 + n - 1 c k
n c k - 1 = n - 1 c k - 2 + n - 1 c k - 1
that is indeed the same statement
look at the rhs of your (first) equation and this expression
2 [(n-1) c (k-1)] + (n-1) c k + (n-1) c (k-2)
replace n with n+1 here
n c k = (n-1) c k + (n-1) c (k-1)
why
see what happens
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did we get it?
eyy noice
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How to derive this formula for the area of the pedal triangle of a point M wrt ∆ABC with O as the circumcenter using inversion?
I have seen 2 proofs of this but they both use trig
I think I need to find an inversion that swaps (XYZ) with (O)?
This is an excercise for inversion, so I need to use inversion
sorry might just be language barrier but what's inversion ?
oh ok no I just didn't know this nvm
so if I get it you need to find a function that map from the circumcircle to the pedal triangle
Well at least that's what i thought
But idk, which is why i'm opening a help channel
Wait... I might have an idea
Circumcevian triangle ~ pedal triangle
oh ok I get the idea we use the same tools in optic physics
So inversion at M with power equals power of M wrt (O) might work
One sec
k
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Question regarding the constructability of product of numbers with ruler and compass. The definition of D here is the following: $a\in D$ iff the point $(a, 0)$ is constructible from the set of points ${O, I}$, where $O$ is the coordinate origin and $I$ has coordinates $(1, 0)$. The definitions of constructability and allowed opereation are shown in the second screenshot.
Dedekind
The solution apparently suggests to draw an arbitrary line through $O$ at arbitrary angle, mark $b$ on it and use the similar triangles. My consern is that using only alowed operations, are we allowed to draw an arbitrary angle line? For it seems we can draw only lines between two previously constructed points, and here there is no second one
Dedekind
@inner star Has your question been resolved?
isn't the first line you draw from O already arbitrary?
if you don't want arbitrary angle you can just make a 60 degree angle too. I guess that doesn't adress your question. Undoubtably "random" angle will introduce new length that might not be constructible, so it's best to use a random constructible angle.
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Sorry for the late responce. No, it's no arbitrarty, it passes through points $O$ and $I$, from the set that is initially given
Dedekind
oh so straight edge and compass gives O and I?
but again the point I said was: just pick a random constructible angle
they are the starting points (unit interval lengh) that are given before any constructions
thank you!
btw, could you please recommend some textbooks on ruler and compass constructions with rigorous approach?
lotta angles can be made
just make buncha circles to get small angles
so you really do have lots of choices
and I guess, the arbitrary circle radii are also not allowed, right?
😬 I never read on those books or learn much on ruler and compass
yeah i think so
except on some application of galois theory
mostly forgotten
still, would like to hear
yeah for book recomm you could go there and there are more qualified ppl who can direct you
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np!
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I don't get the solution for this? can someone explain?
convert 1/3 to decimal?
yeah
do you know long division?
yes I do
then you can just divide 1 by 3 using long division
you can write 1 as 1.00000000 if it helps
keep adding more and more zeroes to the write of the decimal point.
so basically it's 10 divided by 3?
1.0/3
with a shifted decimal point
1.0, to be precise.
you're gonna 'assume' its 10 while dividing, but don't forget the decimal point in the answer
oh
10/3 is not equivalent to 1.0/3
similarly 1.00, 1.000 so on so forth. when you're dividing you're 'assuming' the decimal point doesnt exist, but dont forget to put the decimal point in the quotient though
so basically like this right?
isnt the things flipped here (3 is in place of 1.0, and 1.0 in place of 3, but maybe that's the notation you follow in your country
you're dividing 1.0 by 3, not the other way round
and if you continued like that, the 3's would just go on
so that's why it's 0.3333....
yeah, so the numerator should always be the dividend?
fractions are literally division
and denominator will be the divisor?
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I’m struggling to understand how we go from raw data to the normal distribution and the probability density function (PDF)
Starting from the beginning:
I have continuous data (like how much customers spend in my shop).
I group it into intervals and make a histogram.
Then I’m told to use frequency density instead of just frequency, I don’t fully understand why.
From there, my book suddenly jumps to something called the probability density function (PDF) and the normal distribution, without clearly explaining the connection
can someone pls help me, I am mostly stuck in the step where my frequency density-class graph is turned suddenly into a smooth curve with something called "probability density" on one axis and the other is empty?! and they call the smooth curve the normal distribution
i will be grateful for good
@sweet cove Has your question been resolved?
can you like send the text?
what i said is really really what they did
well normal distribution is the approximation for this kind of data
i mean money is continues data, and then for each chunck from (3-10) for example there is 9 poeple who spent an amount in that range
bro this lesson trumatised me for the last 2 weeks
i sleep so i dont study it lol
see the paragraph
i haven't really studied stats, but there's binomial, poisson, and there's normal, and for some reason real life data is close enough to normal
the last one i mean
even binomial is close enough to normal if i'm not mistaken
so yes there's actually a leap in logic there
it just works
now this clearly doesn't work
thank you man but i guess whatever they are doing in my book needs a person who have taken stats and studied like really well, i am just so confued
why is X negative, it's all wrong
but they move the center to the average spending
and it becomes close enough
there's no good reason why they didn't mark vertical axis
frowny no man please, one more graph and i would die
lets stick to my question
well i literally don't know anything else
thanks man
oh you said they didn;t mark horizontal
the vertical is probability density
what is this?
yeah vertical is density
what is that
it's just probability of getting that X
but because it's continuous it's wrong to say that
you can only take an interval and integrate
how they have taken me from the frequency density-class graph to the normal distrubution curve, with new axes, just by simply drawing a curve over my bars?
they noticed it looks similar
they need to add a parameter, sigma²
so it's actually correct
well more corect
“Bell curve”
that's this thing if you heard about it
it just magically looks like real life data often
so they kinda aren;t trying to say anything you didn;t get
“look, similar!’
i always tell people to go sleep
@sweet cove Has your question been resolved?
@sweet cove Has your question been resolved?
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I did I and for ii I got ln(coshx) im not sure how to go abt doing iii tho
if y=tanh^-1 x, x = tanh y and dx = ... (basically thus forth treat it how you would a usub i.e. changing the limits etc)
Ohh ok
I’ll try that
That works great
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this is the formula for cramer rao lower bound I'm usinf
for information lower bound, I use this?
correct
notation tripped me up for a sec since i usually see $\text{Var}(\hat\theta)$ but yeah
blanketism
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show your work
its essentially asking what percentage of the normal distribution curve is above 180 so you would find the z score and find the probability for that z score
idk how it works in ur curriculum but you should have some way of finding the probability of a datapoint being below that z score in a tables book or something
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i dont know how to find B
so far i found A and C, and AC. but im struggling to visualise this and dk what my next step is
@solemn holly Has your question been resolved?
have you tried drawing it ?
A,B,C lie on the line
and |AC| = |BC|
If u cant visualize it draw it
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how come in here we are allowed to do b times height over 2 even tho is not right angled triangle
it is because we know the full height of the triangle
I tho we had to use 1/2 ab sinC
nope that’s for sides
when you need side c
ohh
you can use 1/2 bh when you know the length of the base and the altitude (height) from that base
isnt 1/2 ab sin c for area too?
idk what "ab sin c" is for side c is about then
i got it guys
wait i’m thinking of cosine law
yes this is for area
thanks for trying to help
You can use ab sin(c) to get the area of that triangle. I invite you to try!
if you know height and base this you use 1/2 bh
A=a×b×sin(ab)/2
!done
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ill add that 1/2 ab sin c is a form of 1/2 bh
idk why this one is sorta chilling, but you may need to grab a mew help channel
for example @mossy cliff use #help-21|아리스킨충1 is someone isn't already in it by now
yes
oh im sorry idk exctly how its going here
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No problem, #❓how-to-get-help explains the process nicely 🙂
can someone help here
i have no idea how to proceed
write out formulas for P(X=1) and P(X=0) and E(X) = 10 using X is binom(n, p) so your answer will be in terms of n and p
so 10 = n * P(X=1) or wdym
no
you should have learned the formula for expectation of a binomial random variable
wait i dont understand the difference, there are 2 forumals
one is the (n,q,p)
the other is
E = n * p
E(X) = n * p yes
this isn't a formula at all
????????????
the n over k
whatever
so i did say 10 = n * P
wait how does this help
we still have 2 undefined
you've got 1 out of the 3 things done
P(X=0) is simpler
this is E(X) = 10 = n*p again
yes
P(X=0) is a probability so it's between 0 and 1. not 10
nah wait lets skip that this is more importnat
so the possibiliy for P(X=10) is 5,5 and 4,6 and 6,4 right
5*5 is not 10
product means multiplication *
how will u get X=15 if u only throw dice 2 times
sum means addition +
oh my god i didnt read that
oh my god
yeah so
2 * 5
5 * 2
AND 3*5 AND 5 TIMES 3
its the same
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Please help me out I dont get this at all
61-66
For the graphs it's nice to try some values on the axes to see what you should expect the function to look like.
For instance, in 61, the function along the x-axis (y=0) should look like z=sin(x*0) = 0. Along the y-axis (x=0), it should also look like z=sin(0*y) = 0.
Can you spot graphs which seem to be 0 on the x and y axes?
Or at least rule out some of them.
@blissful comet Has your question been resolved?
0 on x and y?
Like if you look at the graph along the x and y axes, the function should be 0 there.
If you look at graph A for instance, if you follow the y axis the function is going up and down, so it can't be the graph of 61.
for graph A the function is going up and down in xy plane
so shouldnt it be graph of 61
cus sin(xy)
hey
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hi
hello! do you have a particular question in mind?
Can you please post your question?
Asking the actual question right away is more likely to get responses.
Asking "Can I ask...?" or "Does anyone know about...?" doesn't give people enough information to decide whether they can help, and answering can feel like a promise to help with the actual question, which they might find themselves unable to.
The question is right their son
Asking the actual question right away is more likely to get responses.
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.reopen
✅ Original question: #help-27 message
what have you tried thus far?
@simple mesa Has your question been resolved?
i dont know how to approach it
I'd first target the sum, and then the integral
that is just lecture I took

