#help-36
1 messages · Page 131 of 1
Do you know how to integrate sech^2x?
no
Do you know the derivative of tanh?
yeah
What is it?
sechx squared
Then
You tell me then
x- tanhx
+C
cant forget the constant matey
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Can someone explain the solution of 10.7 ?
I was able to get 1/4 sin^2 2xcosx but couldnt continue
I tried redoing it again but idk where im doing wrong. Check out the part written in black
Why did you cancel 2 and 4 u should have multiplied them
which part are you talking about
oh okay now i got you
what changes anyways i still cant continue lol
Actually u would have gotten it
i got cos5x - cos3x - cosx over 8
<@&286206848099549185>
@gleaming bluff Has your question been resolved?
<@&286206848099549185>
@gleaming bluff Has your question been resolved?
<@&286206848099549185>
(cos θ + i sin θ)4 / (sin θ + i cos θ)5 is equal to . can anyone help
?
this is my channel
<@&286206848099549185>
<@&286206848099549185>
@gleaming bluff@gleaming bluff@gleaming bluff
Only ping once
what is the question?
ok but no one came this is why
@gleaming bluff
@gleaming bluff
what happened?>
@gleaming bluffwhats maths probelm
.
this is the last i did
@gleaming bluffgot it
i have seen this, but i still dont know whats your question is.
how do i prove it i dont understand the solution
i did some work but idk where did i do wrong
which step of the solution (which is on your picture) do you not understand?
after 1/4 sin^2 2x cos x
this?
i only pinged twice within a minute. the other ones were pinged within 30min to hour. go mind your business if ur not gonna help.
can you review this
?
?
?
I was actually doing my business but got irritated from your mass pings
okay leave then go back doing your business
as if i am the only one doing it
It's my business, my ownership. you are no one to give order to me
yeah right that helpers tag gives you the right, right?
But that does not mean you mass ping helpers
No!
It never gave you the right to give order
i do not usually ping helpers more than two times. i did not get any help so this is why i did it. i already explained it and it already happened so why not move on ?
what are you trying to prove here you're literally wasting time
If you get no reply and mass ping, you'll get nothing
where does this come from?
okay you can leave after this very important fact
Again, it's my business
can you leave?
<@&268886789983436800> @latent jasper is spamming this channel
you see there it is written as sin^2 2x
thank you.
Pings helpers
No reply
Pings again
Tells helpers to leave
HuH??
i am not telling helpers to leave i am telling you to leave
ThM is trying to help and you're spamming this channel rn
which causes a waste of time for both of us.
Spamming?
are you sure?
i actually expanded sin^2 2x there
if I draw it its not the same
(modding on mobile is so annoying but I muted for a bit, nikky please don't spam like that when you're not helping)
thank you
but also ghio consider whether repeated Helper pings are useful
yeah i apologize for it but even it already happened and someone is helping me he is disturbing the channel for no reason
still, i am sorry for that.
what is the maximum amount of time i can ping helpers? Consider that at first i did it and someone came but they left without answering my question. Can I tag helpers again?
as my drawing shows you obviously missed the "-" in using this formula:
oh right i am actually solving it again and i think i am close to the answer
let me share my progress
i think i got it but i only need to make it positive
make the -2
positive
i dont know why i got the answer like this though
i think i did another error while using the formula
you do it now step by step the same way as in the "original" solution. why dont you compare it with this - you will see your error.
you again missed some "-", if i see it the right way.
alright found it. thanks a lot
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for the function f the equation becomes -2^2+6 but idk if the answer will be 10 or 2
i don't get it it's 4?
wait lemme think and use my brain
so it's 10 then
(-2)^2 = (-2) * (-2) = 4
negative times negative = positive
i put it in desmos and it said -4 so i was confused
-2^2 = -4
(-2)^2 = 4
whats the full question
when substituting stuff in put it in parentheses
ex. when subsituting for a in a^2
a = -5, a^2 = (-5)^2
ok
but if the thing is sort of like
2x^3 - x^2
then follow order of operations
ex.
x = -1
2(-1)^3 - (-1)^2
2(-1) - (1)
-2 - 1
-3
those numbers are confusing me
which numbers
just the whole thing
this whole example
but i think i'm good for now
why
oh i didn't fully solve it
it's 68
that was just for one
can u help with this one
what does it mean when it says f(-1) does it mean the coordinates of when y=-1?
i think it means to substitute -1 into it
it's just a graph tho
basically what is the value of y when x = -1
i guess
it means to find the values of x such that f(x) = 0
in your case its just the values of x such that y = 0
yea i guess
do u know how to do end behavior cause i forgot
nop but i seaeched it on google
just look what happens when x goes to positive and negative infinity
oh i remeber now
when x goes to negative infinity y goes to infinity
type shi
when x goes to infinity y goes to infinity
@surreal vault are you still here
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Can someone find the volume and surface area of all 4 of these please
@woven galleon Has your question been resolved?
Can someone help
Uhh
Wait
For 1.
?
Idk Bru
So just multiply them together for volume
So 196
Then how do I do surface area
Alr
So what would that be
7x4x2 7x7x2?
Like that for the first bit
so 210 for the SA right?
for 3 V=336
is SA 208?
if not lk what i did wrong
@glass beacon
How I did 8x7x2
Uh alr
196?
@glass beacon
Wait nvm
292 right
Is the SA for 2 97?
@glass beacon can you help with just 3 more
If you can just give me 4 and 2 then that’s all I need please
B and h is 5 and 4 so I don’t get it 5 n 4 / 2?
faiyrose
2r=d 2 r = d
faiyrose
or you can just do $\int_{0}^{6} \int_{0}^{2\pi} \int_{0}^{4} r dr d\theta dz$
N(μ,σ²)
: >
😭
Yes uh I got 301
Result:
301.59289474462
faiyrose
faiyrose
i got 96
is that right
πr² I’m just bad at this bro mb
What is that
πr²
Yo I got class in like 5 mins can you just plz tell me what the volume and surface area is😭
faiyrose
10
faiyrose
80
faiyrose
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faiyrose
alr
wait is that the volume
or sa
alr
wat was the volume btw
oh alr ty bro
u saved me
God Bless You😁
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how to solve problem by creating equations
Please show the original problem, exactly as it was stated to you, with the entire original context. A picture or screenshot is best. If the original problem is not in English, then post it anyway! The additional context might still be helpful. Do your best to provide a translation.
bruh
What problem do you want to solve?
any example of solve problem by creating equations math
let me try to find the thing
Yeah, it’s not really procedural thing, depends case to case
Say you have a problem like: Tom's mother was thrice the age of Tom at that time 10 years ago. What are their ages now
Are you talking about problems like these?
nope
Two faucets flowing into a tank without water will fill it in 6 hours. If hose 1 is left alone to fill the tank, it will burn faster than hose 2 running alone, which is 9 hours. How long does it take each faucet to fill the tank?
here
i took some time translating since im asian 👽
i only know that we find how long does fauncet 1 take to fill the tank
and fauncet 2 too
So you need to find 2 variables, lets assume they are a and b. (The time taken by faucet 1/2 to fill the tank)
alr
Let the rate of filling of each be r1 and r2 (So by r1, I mean that in 1 hour, it can fill r1 litres). And the volume of tank be V litres
So we can write r1 * a = V = r2 * b
And (r1 + r2)*6 = V
what the sigma..
in here first we call the time it take for fauncet 1
and fauncet 2
to fill the tank
then we start making things up that somehow makes sense and create equations
x and y or smth
How do you start thinking about this?
You need to find the time it takes to fill for both the faucets. Lets say t1 and t2.
Now you assume, that in 1 hour, faucet 1 fills r1 Litres and faucet 2 fills r2 Litres.
So how many Litres would say, faucet 1 fill in t time? r1 * t. But you know that r1 * t1 = volume of the tank in litres and similarly r2 * t2
18 hours is the answer
thank you
😆
You can ask if you have any confusion
Its very easy if you take time to understand
It won't take you time once you get it
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i am having some diffiuclty with finding variance of Y
i built this table
so E[y]= 9/16
VAR = E[X^2] - E[X]
isn't E[X^2] also 9/16?
so var=0
E[X^2] = 0^2 * 7/16 + 1^2 * 9/16
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is correct?
what is the error?
the first is you are missing dx
the second, more prominently, is you took the x out in the numerator wrongly
$\frac53x -\frac73\neq\frac13(5-7)x$
yes, thats correct
from there just do partial fraction
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Its wrong
.reopen
✅
they told me it's right
Its not
@sharp goblet told me it was well done🤦
Multiply fractions
<@&286206848099549185>
where is the question
the integral above
Did you just
Split the integrals
integral of f(x)g(x) isn’t equal to the integral of f(x) times the integral of g(x)
wdym
oh right, that only applies with + and -
🤦
Now?
I try to expand with Taylor
is right?
@mortal berry Has your question been resolved?
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@mortal berry Has your question been resolved?
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can you please explain me what a cylinder set is? I read it's definition n-th time, and I still don't get it
can you share definition?
my prof told me that cylinder sets are sets made like this, but it makes no sense (as T is a set, then R^T is a set of function from T to R, therefor X is a function which belongs to borel set)
i get to the moment when projection is defined, and then I get lost
#proofs-and-logic might be able to help.
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hello everyone! just wondering how i get a system of vectors as a linear combination
as in I have vectors a = (1, 2, 3), vector b = (2, -3, -4), vector c = (1, 0, -2)
can i just set this up and eliminate variables and avoid a matrix?
wdym?
a linear combination isn't a matrix 
so if i need a + b + c = (3, 4, 5) as a linear combination
ah, okay
you can use a matrix as well but i quite frankly dont want to
can i just set this like
what is c1 c2 c3
variable
can switch it so like
c1 = 1x + 2y - 2z
actually thats wrong it would be uh
if you're gonna use elimination, why not use a matrix? 
hate matrixes
but ill use em
anyways im just confused as to what this wants me to do and how to set it up
we want to find scalars x,y,z such that xa + yb + zc = (3, 4, 5)?
yes
we can write x(1, 2, 3) + y(2, -3, 4) + z(1, 0, -2) = (3, 4, 5)
then distribute the scalars in, and then add the vectors together on the LHS
yeah, the rows should be columns and vice versa
i did
hold on
im getting something irrational now
uhm
i messsed up and idk where
do i want to make this matrix verticale
vertical
uh
i mean
like (1 0 0)
(0 1 0)
(0 0 1)
identity matrix
not necessarily
if you have free variables in the third row apart from $x_3$ then you can solve the system
45
you have $x(1, 2, 3) + y(2, -3, 4) + z(1, 0, -2) = (3, 4, 5)$. This equates to $\begin{pmatrix} 1 & 2 & 1 \ 2 & -3 & 0 \ 3 & -4 & 2 \end{pmatrix} \begin{pmatrix} x \ y \ z \end{pmatrix} = \begin{pmatrix} 3 \ 4 \ 5 \end{pmatrix}$, as you correctly stated. I suggest instead of performing row operations, you solve this through elimination or substitution, or a combination of both.
45
i was using guassian elimination and got stuck
but row operations could be used to solve this
so
What are you stuck on?
back to ole reliable
i messed up somewhere, ended up with third row: 0 0 0 = a weird number
yeah then ig instead of gaussian elimination, use the normal methods
unless the question specifically asks for that
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@haughty pulsar Has your question been resolved?
quelles sont les valeurs que peuvent prendre x^2 et y^2 mod 4?
jsp
att
excuse moi on est passés mod p
mod p?
oui
bahh ya bcp de possibilités jsp
d'après la question d'avant, x^2 + 1 et y^2+1 c'est comment mod p
different de 0 mod p
ok
donc?
j'essaie de voir où l'exo veut en venir
À p/x
pttr utiliser la question d'avant
La solution c'est évidemment en utilisant l'absurde
ok je pense j'ai la solution oui
si par l'absurde x n'est pas divisible par p
alors on pose u un inverse de x mod p
et donc a = uy vérifie...
oui
bah
même fermat
donc inverse au programme
non
bah si regarde
x et p premiers entre eux
ux + pv = 1
donc ux = 1 mod p
u inverse de x mod p
ouais pas au programme
bof bof
pas de notion "inverse"
bon ok
alors refais ce raisonnement
on en vient à u tel que ux = 1 mod p
et regarde qu'est-ce qui se passe avec a = uy...
jsp
0 mod p
oui
bon bah comment on fait apparaître a là dedans ?
jsp
double bezout?
on ne peut pas car p peut diviser ou ne pas diviser y
multiplier quoi
tu me dis des consignes sans les terminer
il faut bien que tu essaies de les terminer par toi même
sinon on apprend pas
regarde moi ce que j'ai fais
check?
oui
bahh u²x² + u²y² = 0 mod p
x = 1 - pv
ux*
I see where this is headed
oh shit
its simple
thx bro
@scarlet sequoia you tha goat
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hi i need help. could anyone come in a voice call?
!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/
whats the topic?
If english is not your first language, VC may be an even more difficult channel of communication
1+1/3+1/5+...+1/endless shouldnt equal endless right? it should get closer and closer to a specific number right?
it should be fine i hope
I believe it is endless
not necessarily
Are you familiar with the Harmonic series?
"Infinite series" by the way
im not sorry
Harmonic series: $\frac{1}{1}+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+\frac{1}{5}+...$
SWR
I ran it through a python code with really high numbers (smth like 1010000000) and i got smth around 11.35
But that's not infinitely high
yes but from now on the value that i will add is increasingly small
what is your native language?
german
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yes, okay thank you
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I need help with binomial expansions
I will fully explain myself
This question is confusing to me because when using this general equation:
the k value by the way is one less than the term
so if the sixth term is what we need to solve for, the k value is 5
anyways, I'm not sure what they mean by ascending powers of x or descending powers of x
Like, is the general term in itself based on ascending powers of x or descending
The correct answer to this question is 7/4x by the way
but im wondering what the answer would be if it was ascending powers of x instead of descending
youd do it in ascending powers of x and find the value for the sixth term
why did this person do it this way then
they simply took the 6th term in descnding powers of x
and it was the correct answer
wait
how would you do it in ascending powers of x though
like what does that mean in itself
whats the difference between finding the answer between descending and ascending
thats my confusion
ok so
and how does it apply to the equation
right
from a quick calculation
in ascending powers itd be 7x^9
i did this quickly so it might be wrong
(e.g. something like 1 + x + x^2 is "ordered" with the powers of x increasing [ascending powers of x], whereas x^2 + x + 1 is "ordered" with the powers of x decreasing [descending powers of x])
but in descending powers of x you have an x^-1
^
yes
i understand that part
however, what i dont understand is how i find the value of k and solve for the term and simplify
you just vary k
what does that mean
if k is 5 in descending terms, then k has to be another value in ascending terms right
i want to know how you would find that value
yh k would be 3 in ascending i think
sorry im not explaining myself very well im kinda tired
essentially every value of k corresponds to a power of x
you have to see which power of x youre looking for and use that k
heres something i did
my logic was that since in ascending order of powers we have to solve for the 5th term
in descending order of powers, naturally we'd have to solve for the 3rd term
it was the same term regardless
so i tried solving for it and got the question wrong
when expanding the binomial
we get this
Assuming you're writing the terms as $\binom{6}{k} x^{6 - k} (-2x^2)^{k}$, you won't get the terms in decending powers of $x$ (as $k = 0$ gets you $x^6$, but $k = 6$ gets you $64x^{12}$)
@tulip coyote
so if it ever asks us a question for descending powers of x we have to turn it into ascending powers of x and find the appropriate term?
if thats the case then this person didnt solve the question properly
they simply took the 6th term from descending powers of x and got k and plugged it into the equation
instead of turning it into ascending powers of x first
wait
im so confused
when that equation got expanded it naturally turned into descending powers
of x
even though it should be ascending
meaning they purposely altered the equation so that we just look at the term and simply solve for it without thinking any further
at least thats what i am assuming
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hey really quick, is this a construction of a median?
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let $f(x)$ be a function with three continous derivatives such that $\abs{f^{(3)}(x)} \leq \frac{1}{4}$ $\forall x \in \mathbb{R}$ and let $P(x) = 3\left(x-1\right) + 5\left(x-1\right)^2$ be the second order taylor polynomial at $x_0 = 1$. Find $Q(x)$, the taylor polynomial of degree 2 of $g(x) = 4x + x^2 + f(7-3x)$ in $x_1 = 2$ and calculate the amount of error of a result of calculating $Q(2,1)$ instead of $g(2,1)$
938c2cc0dcc05f2b68c4287040cfcf71
@gentle zephyr Has your question been resolved?
No roles to add or remove, nothing to do.
@gentle zephyr Has your question been resolved?
@gentle zephyr Has your question been resolved?
someone please
<@&286206848099549185>
do you know how to determine a taylorpolynom of degree 2?
degree 2 means, you do only the first 3 terms (up to the second derivative)
so take your g(x) and determine g(2), g'(2) and g''(2).
@gentle zephyr
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so um how do I do the limit thing? where I evaluate the limit thing?
WATERBEAM]
Hello bum chicken
it’s mid
do you like how I accounted for the flipped integral and limit because I’m Australian you guys see everything upsidedown
Go do ur spec 👻

blud is flooding my help channel with valorant gameplay 💀
no
stop losing ur games
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im stuck on part (ii) I end up with two times the right hand term instead of the whole expression. To start with idk where they get the 1/2 sin(t) from nor do i know where i get an extra 2 from. My phones dead so i cant send my working but if anyone can check the final answer itd be appreciated just in case the show that is wrong.
i integrated by parts twice then got to $$b_n = \frac{2}{\pi} \left(\frac{4n}{4n^2-1} \right) \cos(n \pi)$$ as the coefficient in front of the sum of sines (used limits $ - \frac{\pi}{2}$ and $\frac{\pi}{2}$ in the integration)
i didnt use the identities at the bottom in the process
I can't believe you've done this
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are you allowed to just graph it
Addition of ordinates it quite tricky
But
Basically
You must find the period of the sin function
And the tangent function
and find their least common mutiple
@final shadow Has your question been resolved?
I mean yeah but it wouldnt be helpful for a test
no calculator test 😢
I got 6 pi
i think it right
so thank you
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Hi
when u have a stochastic variable (or random variable) does it only represent the possible outcomes or does it actually contain the data?
like when u google the definition its just the numbers that the observations can have
but then other times its used to find different things like the mean $\hat{\mu} = \frac{1}{n} \sum{X}$
chrelleren
up until now I thought the stochastic variable was a representation of a test/sample you do of a population and that it contains $x_1, x_1, ... , x_n$
chrelleren
well depending on how its defined, a stochastic random variable is actually many random variables indexed by time (usually)
in general, a random variable is a map $X:\Omega \to S$ where $\Omega$ is your measurement space, and $S$ is some set, usually $\mathbb{R}$
Bair
so the random variable doesnt actually contain any data?
its just the possible outcomes of ur samplespace?
what do you mean contain data? a random variable is just something which depends on an observation you made
so if i was flipping coins, a random variable might be the number of heads i get
like what I mean is the stochastic variable for flipping a coin is the two possible outcomes X = {1, 0} and not the actual outcomes from a test X = {1, 0, 1, 1, 1, 0, 0}
right
wait which
wdym by this then if it doesnt represent the sample u took?
take some sample, say you flip 4 coins, and you call the outcome you get $\omega$, then if $X$ is a random variable that represents the number of heads i get, $X(\omega)$ is the number of heads i got in that particular sample
Bair
so in a sense, the random variable itself is independent of any particular sample, since it represents a mapping from your measurement space to the reals
so if the sample space was the outcome of a dice throw, then the random variable would be X = {1, 2, 3, 4, 5, 6}?
no? once again, a random variable is a function that maps your measurement space to the reals (or some other set)
wait hold on
Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now: https://www.khanacademy.org/math/statistics-probability/random-variables-stats-library/random-variables-discrete/v/random-variables
Basic idea and definitions of random variables
Practice this lesson yourself on KhanAcademy.org right now:
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I got it from this video
50 seconds
im still confused, they are saying what i just said, in that case X is still a map from the measurement space (the value of a coin flip) to a number (1 or 0 depending on the flip)
ion get why it doesnt apply to X = {1, 2, 3, 4, 5, 6}
what you wrote down is a set of numbers, it's not a mapping
are you saying that that's the range of X?
then what is X itself
but how are you defining X? just the value of the throw?
yea
then X is a function which maps from the set of possible rolls to a number which represents the value of the throw
so if $\omega_i$ is the measurement that the die roll is $i$, then $X(\omega_i)=i$
Bair
does this mean the stochastic variable could also be defined as a function that finds the average of a measurement sample? like the average of 6 dice throws
a stochastic random variable is a collection of random variables indexed by time, so they could be $X_1, X_2, X_3\dots X_t$ where $t$ represents the time
Bair
so sure, you could define a stochastic rv like how you said
like $X_t$ represents the average of the first $t$ dice throws?
Bair
wait I thought stochastic variable and random variable was the same
thing is we didnt use the word random variable only stochastic
(im not native english)
they are not the same thing
_ _
ok so if we got a samplespace with different outcomes (random variables) x_1, x_2, ..., x_n then the stochastic variable is the collection of those X = {x_1, x_2 ... , x_n}
yeah
and the samplespace isnt necessarily the whole population right
im just making sure my language barrier isnt causing any misunderstandings xd
what do you mean by population
ive learnt it all in a different language
like say
the whole population is the height of all students in america
and a samplespace may be like 10 classes that are chosen to be done statistics on
?
err i guess if you define it that way
i don't know much about statistics, in probability we just say that all of your random variables in a stochastic random variable map from the same sample space
ah ok fair
its because we got some stats on how to estimate the mean and variance from a sample within a confidence interval
just wondered if the samplespace are the same as those samples
would make sense if it was the case
@short talon but bro ty youve been a great help
no problem, you're welcome
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Can someone help me figure out what I'm doing wrong for this optimization problem? It should be x=7745.9667 but I got x = 1290.994 somehow
I'm confused can't you just make the field really skinny and then the fence would be really small
im not really sure, the problem asks for the shortest possible fence that the rancher can use while still staying 2,500,000 sq ft in area
Yeah so I'm saying you could just make it like 2,500,000 by 1 and the fence could just be 1 foot long lol
so the problem's not very clear...
i dont think thats an acceptable answer haha
Ohh nevermind
I misunderstood the question
it's asking for the total fence not just the fence down the middle 🤦
yeah, i think it wants the perimeter
what'd you give as the answer?
I think your work is correct you just didn't compute the perimeter
You just solved for one of the dimensions
I also got x=1291 (approximately)
so then y is 2.5 mil divided by that which is 1936.5
i gave 1290.994
Yeah I get 7745 when I calcuate the perimeter
even when you add those two it doesnt get 7745 tho
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!15min
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Firstly put the minus sign outside the integral, so $-\int \frac{x}{x+1} \ dx$
lgkoo
right
then the hint here is: x = x+1-1 (use this in the numerator)
yea
have a think about it
got it thankyou
nice
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!status
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
Just see it as permutations of 3A and 3B
A stands for going right, B stands for going up
combinations*
Have you noticed that no matter which path they go, 3A and 3B is required?
eh, permutations is correct?
Both will do
For example?
this is the way my teached me
This is doable as well
But it’s hard to explain
basically just make the edges 1 and sum em up
Congrats
ya
looking at the paths as permutations of rrruuu is my favorite way
Ohhh OK I get it now
r for right and u for up
how does using paths of permutation work if theres a hole on the paths
It still works
it doesn’t
well not as simply as what i just said
Is it cases using perms
yeah
Think about it as a Pascal’s triangle
The sums on the sides would up to the diagonal or that’s how they taught it in my class
yeah but like my method i think also works if there are just paths that you cant cross
Oh ya you’ll also have different shapes it’s not always squares so doing it the way the teacher showed is helpful just in case other methods don’t work with different restrictions
a nice intuitive approach that i like is starting from Q and asking the question at a given point (x,y) how many ways can i go to (x + 1, y) and (x, y + 1) and working your way backwards
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hey guys anyone know how to do this sequence question? T_n = 7 x T_n-1 - 10 x T_n-2 show that T_n = 3 x 2^n + 7 x 5^n
$T_n = 7 \cdot T_{n-1} - 10 \cdot T_{n-2} $ show that $T_n = 3 \cdot 2^n + 7 \cdot 5^n$
Pro_Hecker
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here is an example of a sequence problem. hope it helps (source: https://t.ly/FhkTS)
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pls explain how all the signs changed?
Multiply numerator and denominator by -1
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Not sure how to workout frequency density without class width or frequency
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I differentiated but a very complex calculation is coming and I can't bring the dy/dx term out!
Can you send your working
It's dirty but I did this.
I also swapped the direction. Note that please
Let’s go over d/dx(xy) first
It looks like you know to use product rule, but used it wrong
Can you tell me the definition of product rule?
It's uv'+u'v right?
Yeha
Do you know what the derivative of y(x) is wrt to x?
d(y(x))/dx but what is y(x) here?
You don’t know y(x), but you can still use the same method to get its derivative
By chain rule, you have
[ \dv {y(x)}{x} = \dv {y(x)}{y} \dv {y}{x} ]
shsgd
Now try to do the product rule again on xy
could you explain whats y(x) here
Usually you work with equations that look like y = [some function of x] right?
Here we take y to be the function of x that corresponds to this implicit function
So y(x) would be what the implicit function would look like if it were only composed of functions of x
But you don’t actually have to find it, sometimes you can’t even find it
Could you give an example?
Ok, let C be a circle centred at the origin with radius 2.
C can be expressed implicitly as
x^2 + y^2 = 4
We can also rearrange to make y the subject, so we have
y = +- sqrt( 4 - x^2 )
Then this would be the corresponding y(x) ^
Here it was easy to isolate y, but this isn’t always the case
Does this help?
Oh I got it. Thanks a lot
I got the ans.
Have a good day
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if i continue solving this i get x=1,3467 which is wrong cuz the answer is 3 but idk where i went wrong
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Hi I got a question on how to do part b of this

