#help-17
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Yeah!
Fr
ah
We making it to Adonis mind with this one fr π₯π£οΈ
Ok so Oppai here's a cool one
,, \int_{0}^{1}\frac{x-1}{(1+x^2)\ln x}\dd x
π§πͺπ£πΎππ½
Let's see if Adonis' huge brain can do this
@drowsy igloo
I feel like u should use lnx as t
I feel like we should parameterise it
I feel nothing
No I feel like we should do
This is the play
Yall ever heard of the best integration technique of all time? || Feynman's trick|| 
Anyhow, I'll be pleased to answer questions about this integrals in dms, but I'll close the help channel in order to let someone else have it
.close
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oh
that could work actually witht that
hell yeah it does. I mean, lnx in the denominator? Come on 
Wait I reached some where here
Let me calculate now
Yes ik
We can do x^s
And eliminate lnx from denominator
@hidden kelp
Class duis moment
Using that I have reached here
,w calculate digamma(s+1/2)-digamma(s/2)
Getting close π
Yes
Now I have to integrate
Yes we will get gamma
Yay
Fr
Aah
Give me 1 min
Oof
Imma getting heated
@hidden kelp
Bro
@hidden kelp
Help me find c bro
I got I(s)=log(gamma(s+1)/2)/gamma(s/2))-2log(gamma(s+1)/4)/gamma(s/4)
@hidden kelp
+C
I need the C
@hidden kelp
.reopen
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Hints?
Im not sure how to actually solve it but I have something
Try the most obvious u-sub
then using the same $u$-sub, find $\int_0^1(1-x)e^{1-x}f(xe^{1-x})\dd{x}$
mtt
the most obvious u sub which means...?
as another hint, you would usually choose the u to be something which would make this easier to read
right now it has an f(xe^(1-x))
if it was an f(u), it would be easier to read
so looking at this, what would be the "most obvious" u-sub noticing that its f(xe^(1-x))?
I suppose that was a bit pretentious π
you can reread those words as "the u-sub that you would be the least surprised about"
how can it easy to read
darn im dumb
They meant the u-sub would make it easier to read
look at what's in bold in their message
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I need help with my problem
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<@&286206848099549185>
<@&286206848099549185>
@vast shale Has your question been resolved?
Solve the 2 equations using elimination and then use (x*,y*) as an arbitrary point on the line and use 2 point form of an equation of a line
For the 1st part
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If we have a permutation $\pi = \mr{3 & 1 & 2}$ in one-line notation, then [\mr{3 & 1 & 2} \overset{\tau_{12}}{\to} \mr{1 & 3 & 2} \overset{\tau_{23}}{\to} \mr{1 & 2 & 3}] and so [\pi = \tau_{23} \circ \tau_{12} \circ \operatorname{id}.] But wouldn't it be more intuitive if it was instead $\pi = \tau_{12} \circ \tau_{23} \circ \operatorname{id}$? We first apply $\tau_{23}$ on $\operatorname{id}$, then $\tau_{12}$ on that to go the reverse direction.
id is the first one ?
?
id stands for [3 1 2] ?
Thats why i was confused
You've proven that t23(t12(pi(i))) = i
Hence inverting all the way
pi(i) = t12(t23(i)) because transpositions are involutive
well no
cause t12(t23(1))=2 is not 3
the first line makes no sense to me
I suppose yes it does
but like
ugh I just hate the notation
the arrows should be in the other direction or something
Shall we return to xfg notation rather than g(f(x))?
cause you arent switching the symbols 1 and 2, you are switching the first and second position
no I mean one line notation instead of cycle notation
oh
Why pi(i)?
Just t23(t12(pi)) = id, no?
Yes but that's notationally weird as that's not really usual function composition notation
Is $\tau_{23} \circ \tau_{12} \circ \pi = \operatorname{id}$ fine?
Ok so now we have this
Then we "left-multiply" by t_23
No?
$\underbrace{\tau_{23} \circ\tau_{23}}{\operatorname{id}} \circ \tau{12} \circ \pi = \tau_{23} \circ \operatorname{id}$
in what direction are you reading composition
Ah
From right to left
but then t23 circ t12 circ pi = id is just wrong
what
t23(t12(pi(1))=t23(t12(3))=t23(3)=2
t23(t12(pi)) = id
tf
Ok start from here again
[\mr{3 & 1 & 2} \overset{\tau_{12}}{\to} \mr{1 & 3 & 2} \overset{\tau_{23}}{\to} \mr{1 & 2 & 3}]
So: $\tau_{23}(\tau_{12}(\pi)) = \id$
How come no
We literally follow this?!?
No
Positions!= Values
my tau stands for positions..
tau_12 means positions 1 and 2 switched
Not values
You monster
What's t12 as a permutation?
this is legitimately disgusting
Makes no sense
I have no clue how to deal with that
It switches the positions 1 and 2. So id = [1 2 3] becomes [2 1 3]
That's ok
But in (3 1 2) you swap values 1 and 2, not positions
Otherwise you're doing left composition rather than right composition
In the first step?
Here?
how are you computing the composition [213] circ [132]
I look at [1 3 2]. First position gets mapped to 1, then the first position in [2 1 3] is 2. Now second psoition gets mapped to 3, that's 3 in [2 1 3]. Third position gets mapped to 2, that's 1 in [2 1 3]
So [2 3 1]
so and now we have a huge problem
cause thats not the same as t12 circ [132]
but t12 circ [132] = t12 circ id circ [132] = [213] circ [132]
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$\frac{\Xi}{\overline{\Xi}}$
Kepe
what is the integration of root(cos(x^2-1) * sin(x^2-1))
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wolfram gives me an approx and im not how to find exact value of $\sum_{n=1}^{\infty} (-\cos(\frac{1}{n})+1)$
alaska v.2
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does this equal this?
im aware of the b^log(base b)(whatever) = whatever
but if theres smth multiplied in the power does it just stays in the power
if so anyways, is there any other rule regarding logs to the power i should just know
this is just being combined with normal exponent laws
a^(bc) = (a^b)^c
$e^{\frac13 \ln|x^3+8|} = \br{e^{\ln|x^3+8|}}^{\frac13}$
βΞ±ΞΌΞ©βΟβ €
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find the exact value of:
$\binom{n}{0}\binom{n}{1}+\binom{n}{1}\binom{n}{2}+\binom{n}{2}\binom{n}{3}+...+\binom{n}{n-1}\binom{n}{n}$
BOHO
this looks like a binomial identity where u equate coefficients but idk what coefficients r being equated
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<@&286206848099549185>
ok i got the answer lol but now idk how to explain it
so the general form of equating coeffs is
$(1+x)^n(1+x)^n=(1+x)^{2n}$
BOHO
and then i just equated coeff of $x^{n+1}$ on both sides
BOHO
and then i used symmetry identity to get the LHS look like the q
but now idk how to know that u need to equate x^n+1 coeff
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cant u technically do this by doing 1-p(x=50)-p(x=49)
Please don't occupy multiple help channels.
i have so many answers in my head that probably wouldn't solve the quetion
but i can try ig
should work as well
wait would it be 1-p(x=50)-p(x=49) or p(x=50)+p(x=49)
@hushed cosmos Has your question been resolved?
perchance is this qcaa ia3
i think scnd
- 48
cuz >= 8
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yuh howd u know
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$f(x)= 1$ if $x \geq 0 , x+1$ if $x<0$$
I need to see if the function is limited above
card
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
$f(x) = \begin{cases} 1 & x\geq 0 \ x+1 & x<0 \end{cases}$
Denascite
what have you tried
@lethal heart Has your question been resolved?
I solved it graphically
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hi guys

what does that xer mean
the E symbol means "element of" and the R symbol means "the real numbers"
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β
guys so
what
the third property, what does it mean
so you know that |x| = x also |-x| = x?
Newt
for the second property,
|x| can be x or -x right
no
what does it has to do with square root and square?
|x| = x for all positive number and |x| = -x for all negative number
because square root only have positive answer
this is unimportant but i'm curious why is it written "for all positive number" and "for all negative number"
doesn't -x always mean negative?
no
imagine ur putting value of x = -4 for equation y = -x
y = - (-4) = 4
how is this related with the first principle 
homie had enough fr

by its definiton |x| is for making every number became positive
OOOHHHHH
so they say
|x| = x, if x is a positive number
|x| = -x, if x is a negative number
this means if x is a positive, it'll still be positive.
and if x is a negative, then it'll be positive because there's a negative infront of the (negative x)?
yes
u made it sound so complicated lmao
i think this is more complicated 
Thats so easy
guys is it rlly important to understand what's written here bcs i have a hard time understanding concepts written this way
It works for any value that can replace x
yeah, theyre important for algebra
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in this step, where do the dx's come from?
this is a bernoulli ODE via IF
previous to this step, I have this
this is pre multiplying everything by the IF, however the IF in this case was just x^2 with no dx
ok I have figured out I just forgot to multiply by dx with the IF to put the equation in differential form, however im now wondering what the jump from x^2dv+2xvdx=6x^2dx to d[vx^2]=6x^2 dx is
it doesnt fit grouping form so im not sure how he did that simplification between steps
this
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$y = cot^2(sin(x))$ how do i derive using power and chain rules?
wakamole
can u show me steps .plz
Ok if I am still around
I hope I did this properly
I'm error prone but this is basically what you should do
,w d/dx((cot(sin(x)))Β²
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someone please help or pm me
what have you tried
.
https://en.wikipedia.org/wiki/Convolution_of_probability_distributions this might be helpful
The convolution/sum of probability distributions arises in probability theory and statistics as the operation in terms of probability distributions that corresponds to the addition of independent random variables and, by extension, to forming linear combinations of random variables. The operation here is a special case of convolution in the cont...
maybe 
yes, here you go
look at the end there
so assuming you are able to determine the constant combo indicator function which defines f_X and f_Y, you are set
Is that discrete though? Looks continuous
theyre all continuous
only the statement at the top is about discrete
it continue
i included that portion since it defines the variable Z
but, it follows more or less directly here
the desired pdf is $f_Z (z)$
jan Niku
so assuming that @ancient vapor can describe a uniform pdf as a function
the answer is just there
@ancient vapor Has your question been resolved?
idk how i only know the uniform dist of X and Y individually
you need to click β
also i dont think i even learned convolution
or the channel is going to close
idk you need to learn it necessarily
its described in that paragraph there
can you use the cdf method?
idk what that is
when you get the cdf of Z = X+Y and differentiate it
to get the pdf
if you dont know could you just walk me through the convolution then
never learned it before
all youll need is the pdf's of the uniform distributions
its probably helpful to write them in the form of like
so define some set $S = [a,b]$, then write the indicator function as $\qty(\frac{1}{b-a}) \mathbb I _S (x)$
jan Niku
so what this means is that I_S (x) is 0 if we arent inside [a,b]
the 1/(b-a) ensures that its a pdf, so that like
if its really wide, the prob is scaled down
does that make sense?
this is just one way to write or use uniform distributions
i just think its helpful to have these indicators
absolutely not idk what I_S(x) is
i just defined them as
f_x(x) = 1/2 for 0 < x < 2
f_y(y) = 1 for 3 < y < 4
f_x(x) * f_y(z-x)?
and you say our desired pdf is $f_Z (z) = \int _{- \infty} ^{\infty} f_X (x) f _Y( z-x) \dd x$
jan Niku
and you say our desired pdf is $f_Z (z) = \int _{- \infty} ^{\infty} f_X (x) f _Y( z-x) \dd x$
ok
what are the bounds for the integral then
and what do i do with the z inside the indegral
this is where the indicators help
nothing, its along for the ride
the idea is like this
lets start with ... f_X
you say f_X (x) is only nonzero for 0 < x < 2
yea?
i mean, its 1/2 there
yeah
but everywhere else its 0
yeah
$\int _{- \infty} ^{\infty} f_X (x) f _Y( z-x) \dd x = \int _{- \infty} ^{0} f_X (x) f _Y( z-x) \dd x + \int _{0} ^{2} f_X (x) f _Y( z-x) \dd x + \int _{2} ^{\infty} f_X (x) f _Y( z-x) \dd x$
hope this isnt too wide
jan Niku
$\int _{- \infty} ^{\infty} f_X (x) f _Y( z-x) \dd x = \int _{- \infty} ^{0} f_X (x) f _Y( z-x) \dd x + \int _{0} ^{2} f_X (x) f _Y( z-x) \dd x + \int _{2} ^{\infty} f_X (x) f _Y( z-x) \dd x$
sure lets work with it
you see what i did?
i split up the bounds
hopefully its suggestive
can you simplify this?
look at the interaction between f_X and the bounds
nope
you get lucky
were integrating over x right
so lets say that first integral, x is swept over all values from -inf to 0
but, thats not a concern
f_X (x) is 0 over that entire region
so the improper integrals are 0?
oh yeah i see because theyre out of bounds
yup
$\int _{- \infty} ^{\infty} f_X (x) f _Y( z-x) \dd x = \int _{0} ^{2} f_X (x) f _Y( z-x) \dd x$
jan Niku
$\int _{- \infty} ^{\infty} f_X (x) f _Y( z-x) \dd x = \int _{0} ^{2} f_X (x) f _Y( z-x) \dd x$
now what
is f_x(x) * f_y(z-x) = 1/2?
see, here
$f_Z (z) = \frac 12\int _{0} ^{2}f _Y( z-x) \dd x$
jan Niku
wait does this turn f_y into a cdf or something?
lets say $f_T (t) = 1$ for $3<t<4$
jan Niku
no, its a little weird
convolution is harder to explain in this context than in others
but you can think of it as like, combining two things by pulling out values at each point in some domain
its sweeping the two pdfs over each other
so 3 < z-x<4?
for f_Y(z-x)?
there's gotta be something you can do with that interval
sorry i thought i had this but i need a sec
no problem
man this gets more complicated than i thought 
i really want to use an indicator function
do it with that instead
i think i have the rough answer but theres case work to do
is it for each interval?
it honestly makes me wonder if you could just figure out the answer by casework
well okay
you understand what indicator means if i write it
call $S = [3,4]$
jan Niku
so we want $f_Z (z) = \frac 12 \int _0 ^2 \mathbb I _S (z-x) \dd x$
im not writing a 1, here
$f_Y (y) = (1) \mathbb I _S (y)$
when you say do it by cases, do you mean for each sub interval of z in [3,6]?
then it must be that $3 \leq z-x \leq 4$ so that $z-4 \leq x \leq z-3$
jan Niku
cases just appear
which you maybe anticipate
i dont know if we can start to sub in values for z, here
it makes our life easier
is the problem describing the region here?
like i believe that we can say $-1 \leq z-4 \leq x \leq z-3 \leq 3$?
jan Niku
yea
im really starting to think that this is the wrong way to do it
and youre supposed to just suss it out by casework from the get-go
i have no idea how to do it but graphically it's really easy
yea
red and green triangles are 1/2, and the blue thing is just 2 of those, so it's 1
hi jan 
hi frosst
do you know how to get the area of the blue shape in the middle using double integrals? I forgot all of multivariable calc
u come to save me again
I suggested convolution
but im beginning to think this is overkill
i imagine we can just casework it out
so we got X ~ U(0, 2), Y ~ U(3, 4)
but its not becoming obvious to me
and we want the pdf of X + Y
ye
cdf method?
Let $W = X + Y$.
[f_W(w) ={f_X*f_Y}(w) = \int_{-\infty}^{\infty}f_X(x)f_Y(w-x),dx]
i think it's w-x right?
yeah
yea but the bounds look sus
frosst
we worked through this part, if its helpful
yes
ok
got to here
let's look at f_X(x)
but i dont want to stop you
i'd rather do it from scratch cos there's a lot to read and this isn't that long
[f_X(x) = \begin{cases} 0.5 & 0 < x < 2 \ 0 &\text{otherwise}\end{cases}]
frosst
[f_W(w) = \int_0^2f_X(x)f_Y(w-x),dx]
frosst
because when x is outside (0, 2), the first function returns 0 so the integrand is 0
so the integral is 0
yup got that
okay let's look at the 2nd function
[f_Y(w-x) = \begin{cases} 1 & 3 < w-x < 4 \ 0 &\text{otherwise}\end{cases}]
frosst
yeah this is where we stopped pretty much
so here this is the same as saying 3 + x < w < 4 + x
oh no that's bad
[3 < w - x < 4\iff -4 < x - w < -3 \iff -4 + w < x < -3 + w]
frosst
so when x is inside these bounds, f_Y(w - x) = 1, when it's outside we get 0
does that make sense
yeah but what do we do with these intervals
yeah so
so in order for our integrand f_X(x)f_Y(w-x) to be a non-zero function, we need both to not be 0 at the same time
inside the bounds where at least 1 of the pdfs are 0, the integral for that part is just 0
this is the reasoning for
outside 0 to 2, the integrand is 0 because of the first pdf
what this means is we only care about when [x \in (0, 2)\cap (-4 + w, -3 + w)]
frosst
or, we can say [\max(0, -4 + w) < x < \min(2, -3+w)]
frosst
hence we get
[\int_{\max(0, -4+w)}^{\min(2, -3+w)}f_X(x)f_Y(w-x),dx]
this is where i stopped lol
frosst
now, inside these bounds, the pdfs are both non-zero
and since they are only piecewise 1 way, ie, they are 0 or just 1 function
we can just replace it with the non-zero part
so,
[f_W(w) = \int_{\max(0, -4+w)}^{\min(2, -3+w)}1\cdot 0.5,dx]
frosst
[f_W(w) = 0.5(\min(2, -3+w) - \max(0, -4+w))]
frosst
yeah i see but why do we say max(0,-4+w) instead of min(0,-4+w)
you want to be sure that you dont go below 0
so you were lost here?
oh got it
going from here
at this point you just need to test the boundary values and see what the piecewise looks like
for example, when -3 + w > 2, the min always returns 2
this happens when w > 5
wait before that, is W in [3,6]?
now when w > 5, max(0, -4 + w) returns -4 + w because 1 > 0
dont worry about that
it'll pop out later
oh no
you're right
you do need to care about htis
so you also have 3 < w < 6
so let's build the pdf
[f_W(w) = \begin{cases}
0.5(2 - (-4+w)) & 5 < w < 6 \
0.5(\min(2, -3+w) - \max(0, -4+w) & 3 < w < 5 \
0 & \text{otherwise}
\end{cases}]
frosst
[f_W(w) = \begin{cases}
3 - 0.5w & 5 < w < 6 \
0.5(\min(2, -3+w) - \max(0, -4+w) & 3 < w < 5 \
0 & \text{otherwise}
\end{cases}]
frosst
now when w < 5, the min will return -3 + w instead
when w > 4, max(0, -4 + w) still always returns -4 + w
[f_W(w) = \begin{cases}
3 - 0.5w & 5 < w < 6 \
0.5((-3+w) - (-4 + w)) & 4 < w < 5 \
0.5(\min(2, -3+w) - \max(0, -4+w) & 3 < w < 4 \
0 & \text{otherwise}
\end{cases}]
frosst
[f_W(w) = \begin{cases}
3 - 0.5w & 5 < w < 6 \
0.5 & 4 < w < 5 \
0.5(\min(2, -3+w) - \max(0, -4+w) & 3 < w < 4 \
0 & \text{otherwise}
\end{cases}]
frosst
now between 3 and 4, what happens to the min and maxes
@ancient vapor do you think you can work through that?
where'd you get this
min(2,-3+w) is gonna output -3+w right?
yes
and max(0,-4+w) is gonna output 0
uh huh
so it's 0.5(-3+w)...
oh that's your answer
yes
well idk i didn't do it i was waiting for you to reason through it
lol
i can't tell if this is right without reasoning through it
but yes it's right
so -1.5 + 0.5w
however the thing is i didnt learn convolution or any of these methods in my class
so what did you do in class then
If we take F(W) = P(W < w) = P( X+Y < w), then differentiate F(W) to get f(W)
yeah
this is the way via cdfs
do you have time to do it this way
my trouble is just figuring out the bounds
or really just setting up the integrals and intervals
im trying to remember how you do this
cos i've only done cdf method for transformations of 1 RV
not functions of multiple RVs
[P(X+Y<w) = \int_{-\infty}^\infty P(X < w - Y| Y = y) P(Y = y),dy]
is it something like this
frosst
oh wait i think you can do it like that, but isn't this just the convolution?
that doesn't even work P(Y = y) would just be 0
well but how does your course teach you to do it then
cos idk how else
The reason im having trouble is because the notes are insufficient to do the problem
can you show the notes
okay
that's not too bad
so, since X and Y are independent
we colour in the box [0, 2] x [3, 4]
this would be the [0, 1] x [0, 1] box
we dont want this one
like this
yes that rectangle
ok so then, since we want Y < z - X, we want below the diagonal lines
so the area woule be, from z β [5, 6], we have the red + blue + varying green corner
from z β [4, 5] it's the red + varying blue middle section
from z β [3, 4] it's the varying red corner
when starting the problems how am I supposed to even know theres intervals i have to solve the area for
i've never seen this before but it's pretty clever
well
the equation X + Y < z
you can rearrange it into Y < something of X
so it's like a half-plane on the X-Y plane
yeah?
yeah
well
as you vary the z
the line moves
if i give you some arbitrary z value
so the line is just somewhere
how do you find the area of the shaded region?
you do this to it
the red part
you already know
the blue part
that depends on the z value
okay i guess the only way to do this problem is graphically i guess, i dont have enough intuition to do it without it
from z = 4 to z = 5, you need to find the area of the blue part
for your particular z value
alright since it's been a while since ive taken multivariable calc, how do i find the blue part using a double intergral?
which is given by a strange geometric parallelogram shape
i mean it's just a shape
yeah but just in case
i would advise against using multivariable calc
since you literally end up here
well if you really wanted to know
i'd integrate this particular blue region part against the dx direction first
yeah but isnt it just $\int_{3}^{4} \int_{4-x}^{5-x} \frac{1}{2} dx$
gaydan jew
where did the half come from
yeah but then you're looking at the volume under the joint pdf
which isn't wrong
but you said area
if you want to find the area you'd just put 1 for the integrand
and dont forget the dy at the end as well
ohhhh
this doesnt work for the triangles though since they are both 1/2 in area
wait nvm
it will work for the triangles, but the bounds of dy will change with z
okay so i get how to do the areas and all that
but then the answer isnt gonna be the same as when we did convolution
it should be
the areas are 1/2 for each triangle and 1 for the shape in the middle
this is completely different
unless theres a step im missing
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is this a valid notation?
this is supposed to be the chain rule
while i understand the chain rule, i dont understand this notation
plugging in a number into a function is shown as function(number)
so plugging in h(x) into a function is shown as function(h(x))
the function is dg/dh
so dg/dh(h(x)) means to calculate dg/dh then plug h(x) into it
the video intends for you to pick up on that
is the same for dh/dx?
yes
however how do you knows it meant to be pluged as a function instead of multiplied? is there a difference?
the difference is parentheses
think of how you tell the difference between $fx$ and $f(x)$
mtt
i get it now
thank you
took me 2days to understand it π€¦
a bit shocking its simpler than i thought
function notation is not intuitive and not designed well
the dthis/dthat notation youre looking at was specifically worked on for years to be intuitive
functions were not
youll expect it next time
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Hi, could any one help me to solve this problem? - Given set S = {1,2,..., 2023}. Consider subset T of S. If T does not contain any number a minus any b can get the result in set E
, then how many elements are there at most, with:
a) E = {3; 6; 9}
b) E = {4; 7}
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A square with a side of 2 m has a circle inscribed in it and in turn this circle has a square inscribed in it. If this square also has a circle inscribed in it, what is the area between the last square and the last circle.
How do I do this question?
Did you start with it? Atleast the diagram?
^
Hints:
-
||Find the area of the circle inside and square inside of that circle, then subtract them||
-
||To find the area of the inner square, you know the lengths of the diagonals||
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Whatβs the DBM/OVS method when writing a report for comparison in statistics
UM WHAT DO I DO IM SCARED
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@tough onyx Has your question been resolved?
the third point just says that Tasmania and Western Australia's populations have zero migration to each others states
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hello
It is correct but there's a simpler method
Yo
here you can calculate the area of rectangle ABCD and then add the area of square CEFG
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Normally, a very simple topic, two variables, and two equations
But I ain't getting this
for visualisationg u can try
setting p+q = a; pq = b
it will be a lot easier for u to get the solution
ikr π
π«Ά
np ^-^
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Hey, it was looking all good
But then it turned into a cubic equation of b
How much complicated can a two-variables and two-equations problem get?
Ik, that we can find the roots of b, but just imagine how lengthy it gonna be
Is there any simple solution at all?
Here's the problem again:
ye
That let a = p+q and b=pq
And I ended up with a cubic equation of b
I put pictures above
I did it in head and got a quadratic instead
Can you write your steps more clearly? Its subtle to understand current ones
my idea is just for visualising bro ToT
if u write pq and p+q with the same way u get the same prob
so u have to use a different way
So, you have a way to find answer?
Yeah, please
The last step can be b^2(b-4)-1(b-4) = (b^2-1)(b-4)
?
Oh yeah, how I did not got it
Lemme me try now
$$ pq + \frac{2q + 2p}{pq} = 4$$ $\implies$
$$(pq)^2 + ( 2q +2p) = 4pq = a^2 + 2b = 4a$$
What you gonna do with this now?
Cyrenux
Like, how you proceed after this?
You hold on until you do the same for the second equation
Then subtract or add them
Oh, lemme try then
hmm i just draw a graph
and b has 3 possible roots and all 3 are not rational
like rlly bad number
in moments like this we let Photomath carry
Jokes aside, it can be useful for finding mistakes
i agree..
how to get to a new line
What's this now
It's an app that solves problems
Oh, cool
oh thanks
Umm I want to tell y'all how I got this problem/question actually
Because we been really trying for a while
So,

I was trying to find roots of a cubic equation
umhm π€ ?
nice number
So there will be 3 equations on the basis of relationship between roots and coefficients
is it a 3 or a five
4
4
wait let me try something
Ik ik but that is by trial and error
I wanted to find using relationship between roots and coefficients
Rational root theorem
Explain please
Never heard about this, mb
I was bored of trial and error and Cardan's method of solving cubic equations
Wait
If there exists a rational root for the cubic equation axΒ³ + bxΒ² + cx + d = 0, then its in the form x = +- u/v
Where u is a factor of d and v is a factor of a
Sign doesnt matter
Cubic?
Not exactly
Trial and error with an educated guess
Try the guesses with the way i said
Factors of constant, over factors of xΒ³ s coefficient
Yeah I am searching for the exact name of the method since I forgot
This?
Hah always
I meant that calculator option is always available
Ik this
But you gotta know one root for this
Yeah typo, let me fix
This seems quiet simple and useful
ig, the issue is kinda sorted
Fixed
Thanks y'all for your time
This one took way more people I think
LoL
Oh its bc background is transparent
Is downloaded version fixed?
Or it got gray background still
Oh, lemme see in photos app 
Nah, it's still grey
But it's ok
again, tysm all
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Nah, it's normal
In algebra, the rational root theorem (or rational root test, rational zero theorem, rational zero test or p/q theorem) states a constraint on rational solutions of a polynomial equation
a
n
x
n
+
...
what happened ;-; !#?
?
Wikipedia one is easier to read
like y do my texts turn red
here
He thinks i used latex to change color while i sent an image
It kinda more detailed
Oh thats a failed text
elier from the back but ye
That wasnt sent
Anyway, reminder that -2 is a factor of 4 too, so dont only think of positive numbers while considering factors of a number
ye it is called possible roots
Yes
Ok, got it
π«

It could have a rational root still
Like the polynomial (x-2)(xΒ²+x+4)
x=2 is the only rational root
Yeah, I meant for the ones which have only and only irrational roots
And one small doubt
I did closed this help-17 or waeva
How are we still chatting?
nvm joined discord yesterday only
New to things here
It takes a while for help channels to reset
Oh, ok
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hello is there any way of simplifying this equation so that I can easily linearize it?
e.g reducing it to something like this and graphing D^3 against h
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is it just me, or there shouldnt be a minus sign in the [-ln(K-P)] and instead shouldnt it just be [ln(K-P)]
using chain rule, differentiating K - P gives -1, so you need the extra minus
oh right i just redid that on my notebook, thanks
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(5-6d)^2

