#help-27
1 messages · Page 419 of 1
We do
It all depends on the values b, c, d, etc
I'm not sure how to account for how many solutions those have
Cuz for all I know it could be 3
Oh I have an idea
go for it
So as to account for the possible solutions, we can check for f'(x) = 0
and then just draw the whole graph?
well
you can make a recurrence based on the number of roots in the interval (0,4) of the function f^k(x)
.
is root and grapht the same thing
Has 3 intersections aka 3 solutions
A root is basically a solution
Altho roots are usually solutions for f(x) = 0
in the question whats ment by a
The number of solutions I presume
kk
Ooooo
If you look close
You'll notice that all 3 solutions to f(x) = 3 are within the interval [0 ; 4]
Meaning that they also have 3 solutions
And that applies to all solutions
yeah that's my initial thought
and i found a= 3^8 +3^7 +...+3^0
not sure how you found 3^9
it's like a double of mine
Which means for f(x) we have 0, 3
For f2(x) we have 0, 3 and 3 other solution
For f3(x) 0, 3 and 3x3
f4(x) : 0, 3, 3³
I think you just end up with 3⁸ + 1
So 6562
not quite right
Why not
Rip
well basically you draw kind of a chart
dont u jst need to look for what values n to the power of 9 applies this
like this
it's not the power
it's the f(f(f(f(f(x))))) like that
yeah ik
for f3(x) each of the 4 previous values in interval (0,4) yields 3 solutions, so we get f^3(x) = 0 for 14 values
in general any solution in (0,4) will yield 3 more on the next iteration
Yeah that's just 2×3×3×...×3 8 times
Yeah hence why I said 3³
3 solutions, give 3 solutions, which give 3 solutions
That's just exponents of 3
4 solutions give 3 solutions
just find the zeros using midnight formula
let $I_k$ be the number of roots in the interval $(0,4)$, we have $I_{k} = 1 + 3 \cdot I_{k-1}$
k
the number of solutions is $I_k + 1$
k
the solution to this recurrence is $\frac{3^k - 1}{2}$
k
so we get $a_k = \frac{3^k + 1}{2}$
k
yeah that's what im saying about
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Could anyone help me graph the last radical function for number 1A? I’m not sure how
if unsure, start with a table of values
for a)
consider using values of x such that
3-x
will be a perfect square
I meant for number 1A
For the graphing I’m supposed to graph the equations on the left then plug in the x’s right? Because I did c-e then plotted those points first and it feels like I did something wrong
you don't need to complete the parts in the given order
plotting known points is a key component in graphing
there's no issue in getting those first
and for the graph of the first piece
that should connect down to the point you made at (-7,-7)
and you should also determine the x-intercept for that part
So the left top graph I should drag down till it reaches -7,-7?
@glad arrow Has your question been resolved?
<@&286206848099549185>
,w plot y = sqrt(x)
It’d be up 1 unit, right 3 units then flipped over the x-axis
Do you mind answering the second question about the -7,-7 point?
It keeps tripping me up cus it’s not being used but I feel like it’s meant to be
Nvm thanks everyone for the help
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How do I start w/ evaluating this limit??😭 #17
Would I make both the tan into sin/cos
you can
do you know l' hopital?
I don't think so
you can solve this without LH, but you need to know a special trig limit
ok, if not you can also solve it by manipulating it
how would you manipulate it?
in that case, you should rewrite tan as sin/cos
what i would do is first prove lim x->0 of tan(x)/x, because you can separate the original limit into tan3x * (1/3tan2x)
you could also just directly substitute sin and cos
that might be easier
just split to sin and cos yeah
like this?
Yeah
yep
now given these limits, how would you manipulate your current expression?
you want to get a limit in the same form
lowkey i don't think this is necessary 🤔
i'm just working off what they know
well
theres like probably a way to do it our teacher doesnt teach us Im taking a high school class
sure
would i like separate it like this but then also like maybe separate the sines to get the eqn on my formula sheet?
ok specifically this one
yeah ok
what's the limit of cosx as x approaches zero?
ohhh
yeah u also need to know this
like this right
well, what happens when you simplify 3x/2x?
1.5x?
u cancel out the x
yeah
thank you so so much i have solved this thanks to your help!!
no problem
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Define (d : \mathbb{R} \times \mathbb{R} \to \mathbb{R}) by
[
d(x,y)=
\begin{cases}
0, & x=y,\
1, & x\ne y.
\end{cases}
]
\noindent
Consider (f : (\mathbb{R},d) \to (\mathbb{R},|\cdot|)) defined by
[
f(x)=
\begin{cases}
0, & x=0,\
\sin!\left(\frac{1}{x}\right), & x\ne 0.
\end{cases}
]
\noindent
where (d) is the metric from (a) and (|\cdot|) denotes the absolute value. Is (f) continuous at (x=0)? Prove or disprove.
Branshi (Hints only plz)
So I'm a bit confused on this question
I want to try proving this with epsilon delta rather than with open set characterization
To do that for any epsilon > 0 we need to find a delta such that when d(x, 0) < delta, we have |sin(1/x)| < epsilon
We know |sin(1/x)| <= 1
what's the only possible choice you have for delta?
yes
but thats where I'm getting mixed up, what does it mean for delta < 1
does that mean it has to be 0
because d(x,y) only has values 0 and 1
0 isnt allowed?
oh
because f(0) = 0?
mm so are we supposing x is not equal to 0 at all at the start of this proof?
yeah thats for the limit I think
yes so 0 is the only point you can take
then what do you get when you consider |f(x)-f(0)|
just 0?
yes
hm ok I see that makes sense
so you'll have 0 for any choice of epsilon, so long as your delta is <=1
why less than or equal to 1
thats what my professor had in his solution
but wouldnt it be strictly
less than 1
I'm talking about the choice of delta itself
👍
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What is the negation of "Bob likes men and women"
please ping me if you respond
@hasty zodiac
Uhh you realise how "bob likes men and women" is the same as "bob likes men and bob likes women"?
So you can say p = bob like men q = bob likes women
And negate that
~(p ^ q)
if the above was not clear enough, I'll drop a hint and leave continuing to the other helper.
hint: an AND statement is true when both of its premises are true. what conditions should its logical negation satisfy?
ok but hear me out
would it then be
Bob does not like men or bob does not like women, right?
Yeah
let me ponder rq dont close the channel
Take ur time
Bob neither likes men nor women
❌
Huh
That's incorrect
!nosols, and too strong.
As a helper, please do not give out answers that could be copied as a homework solution. Have the student work through the problem themselves and guide them along the way.
Im i too strong for bro💀
Then the negation for and is or
If not explicitly
De Morgan's law yes
My discrete maths prof say that i can use two cases neither, or depends how strong you want
But if you need broad range then use or
"Bob likes men and women"
essentially implies that there exist a man and a woman that bob likes
so the negation is that for all men and women, bob doesn't like any of them
so for the sake of argument, if we say that there is only two genders male (men) and female (women)
then could you also say that the negation is
for all men, women: bob does not like men and bob does not like women
A negation of a statement simply states that that statement is not true
im still wrapping my head around it a bit so apologies if i said smth dumb as bricks 💀
And is both must correcy
I don't know why you are bringing existential and universal quantifiers in the mix
And or doesnt have the case where both is correct
The statement at the end does not cover two other possibilities: that bob likes men and not women or that he likes women and not men. Both of which render the original statement false.
When you say "there exists" or "for all women" you are arguing in first order logic
ok wait i think my brain's getting there
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Aight smellas so I have a lil question that is definitely NOT minecraft related...
Basically, we have a set of n different numbers. First we pick one of them and "mark" it. Then we choose a number from the set at random, until we get our "marked" number (yes, we can choose repeat numbers). After that we mark another number and start the process all over again, doing it α times, yaaaaay.
On average, how many tries would it take for us to complete this process?
So firstly probability of pick a marked number in a single draw is P=1/n
Expected value also 1/P
Which is 1/(1/n) =n
If N is total number of a tries then E(N) =a.n then
a.n tries would be my last answer
i think a(n+1) if you're including the draw where you mark it
Isnt it an?
This is not picking with replacement from a set of different n?
um wouldnt picking any number suffice to mark it making that P of that = 1
Great point
First we pick one of them and "mark" it. Then we choose a number from the set at random, until we get our "marked" number
i interpret that as picking two for n=1
What if that point is also included as one of n rocks?
once to mark and once to get the marked number
also
after that we mark another number and start the process all over again
are we choosing from n-1 numbers here? or does our original number go back into the pool?
I think we are picking with repeats and looking for average?
Nahh we don’t include that one
For example if we have a coin then we throw the probability of head is 1/2 not 1/3 right
oh then it's a * n
what about the other question that came up?
The average of tries
by complete meaning marking all of numbers then picking them each once after marked ?
By complete I mean after we pick the final marked number, where marking the number doesn’t count as choosing it. We could just assume that every time it’s just the number one that is marked I guess, doesn’t change the probability
you want to do this process n times, for all numbers or just a times irrespective of how many times repeat process
Just a times
ok
More so like, you write down your lottery numbers, which can repeat, and randomly choose the numbered balls from the bin until you get all your numbers, where if you don’t get your number you just throw the ball back in
@dense mortar Has your question been resolved?
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can any1 tell me why the n here should be -1/2 and not -1 i checked on internet and the asymptote was y = x-1/2 not y = x-1 , chatgpt told me its because i ignored the very small terms under the sqrt and instead of x(1) it would've been x(1/2x) so y would be x-1/2
and y = x-1/2 is the correct asymptote of the function but i dont get why n is not -1 and its -1/2 i tried to force out x out of the square root and since x goes to inf |x| = x so x -1 -x = -1
@haughty acorn Has your question been resolved?
u can't use the limit difference rule here
which is presumably how you got -1
,, \lim_{x \to \infty} \qty(|x| \sqrt{1 + \frac 1x + \frac {1}{x^2}} - x) \neq \qty(\lim_{x \to \infty} \qty(|x| \sqrt{1 + \frac 1x + \frac {1}{x^2}} )) - \qty(\lim_{x \to \infty} x)
slayla
but why
you need the limit of at least one of the functions to exist
to even use the "rule" or whatever you want to call it
by exist i mean the limit should be a finite real number
in this case both individual limits don't exist, so it's outside the conditions required to use said "rule"
infinity + finite number = infinity
finite number + = -infinite
but we're dealing with the infinite - infinite case, which is an indeterminate form
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hey
could anyone help me with proving that the circumcircle of BCX intersects line AX at its midpoint?
BX and CX are tangent to the circle in the diagram
Apparently it can be done with "striaghtfoward" angle chasing but I tried for almost an hour and still haven't found anything
As in circumcircle intersets AX at D? Just making sure D is the midpoint here
no no the circumcircle intersecting AK at its midpoint (not marked on the diagram)
Hm, do you have any intuition as to why angle chasing could help prove the result?
that what the book said
I'm refreshing my geometry, so you'll have to give me a sec
thanks ❤️
Lets go timmy
Do you have any explicit way to determine anything about the circumcircle? E.g, radius, centre, bla bla bla
Thanks bud
Nah not really
It would certainly help to have a demonstration, aka a diagram of the circumcircle
You sure you don't have any formulas for circumcircle stuff handy?
I'm drawing a sketch of what i have so far
eh I tried proving the midpoint of AK and points B C X to be concyclic but it didnt work
Is M the center point of BC?
Have you tried converting this onto a cartesian plane?
Defining some origin would be helpful
Think about a good origin
no i've not learned any computational geometry to do that
Hmm, computational geometry? You know how to define lengths and distances and allat in R^2, yeah?
That should be all you need
Everything else is derivable
does it help solve this problem tho
Hey man, never know until you try
If you can show some congruence or similarity, I think this problem can be solved easily
But
It's probably easiest in some coordinate system
What are your thoughts on where you should place the origin
The circumcenter of ABC maybe
I think I solved it?
wait nvm
I SOLVED IT
how do i close this thing
/weather clear
/close
hmmm
.close
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what would be the bridge between cavalieris principle and riemann integral
@spring oasis Has your question been resolved?
care to elaborate
cavaleris theorem says that for the cross sectional areas at height h of a solid, if you sum them from minimum height of the solid to maximum height of the solid you get the volume of the entire solid, it also says that no matter the positioning of the cross sectional areas at height h in tridimensional space the volumes will still be equal to each other if the cross sectional areas at height h are the same
I was trying to relate this two terms together because
cavalieris principle was stated like way earlier than riemann integral and riemann sum appeared
so maybe it laid some insipiration to riemann perhaps?
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hi guys i am new I am doing math homework and need help the answer is done using calculator and my head i am told it's wrong but my math is accurate i checked and doublechecked could someone please help can i get help here
!da2a
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.
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ok the problem set is 45.3, 45.6, 46.1, 46.5, 47.2, 47.3, 47.6, 48.1, 53.3, 54.9 and i need to find standard deviation
my answer was 104.3755632
that is way way too big to be the standard deviation
it asks for the full number i get no rounding
even if you square root it it looks too big
is this just the sum of squared deviations or something
so then what am i doing wrong i did the equation and math on pencil, paper, and calculator and got it 4 times in a row
you're using the wrong formula then
same exact answser each time
standard deviation is supposed to measure how far away from the mean the data points tend to be
right
you should send a picture or screenshot of your work so helpers can see where you went wrong
so what is my mistake i can send a pic of my notes
do these data points look like they're 100 units away from the mean?
how should i know
this is the only guess i have based on how giant the number you got was
i thought i did do that
i mean i was going according to a video youtube as my teacher provided no information on the lab and it's extra work required for a statistics college course
what's your mean though
it looks like the formula you have there is for sample stdev though
so instead of dividing by n you want to divide by n-1
so not exactly averaging
I don't see you writing down the mean anywhere
ok i am confused
also i didn't write everything down just the parts that weren't easy to figure or remember
ok that's a little suspicious
it looks like you used the median instead of the mean as well
the mean should probably be one of those things in the writing down
unless they happen to be exactly the same
also it doesn't ask for everything i wrote just range mean and st deviation
that's exactly what I thought as well. you have the median written down but not the mean
in a calculation where the mean is key
yeah and if you look at the actual calculations he uses the median
because the mean is well nevermind the time ran out it switched to a new set of numbers

ok this time use the mean instead of the median
and then divide your answer by n-1 and then square root it
dreyuk out
i get 5 tries i must've hit the try button on my last try i mean i ran out of tries
i did use the mean not median the median was 47.25 correct and the mean was 48.19
but i thought you square root it before the n-1 as it's pemdas
then this does not add up. 45.3 + 1.95 = 47.25.
in fact every single one of your (x - mean) is done using the median.
i just followed exactly as the video said do i need to share that here to find out what i did wrong
we're telling you what you did wrong already.
not sure what new info the vid would give but if you want, no harm sending 'em
where did i mess up following
the vid used the mean in (x - mean), as it is supposed to, instead of the median
you used the median instead
(which is the same mistake we've been telling you)
i swear i used the mean not median
^
tha's not what i added it was 47.2 and 47.3
and the median would be 47.25.
right and that's what i got
but that's the median
not the mean
and note that when I added (x - mean) back into x, I got the median
right i didn't use the median i used the mean of each number
I should have gotten the mean
like the video says
and I'm telling you that you accidentally used the median in your calculations
ok i won't argue i came to you for help but i just don't see what you mean
you said the mean was 48.19 and the median 47.25.
right
pay attention to those figures.
now, if I subtract the difference between x and the mean from x itself, do you agree I should get the mean?
i think i see what you think i did the math was wrote there because i ran out of room on the page next to median
it's grouped but not exactly the same
that's not the issue. the writing is not the issue
ok sorry then i just don't seem to grasp what your telling me then
because you didn't let me finish
now, going back to that message, do you agree?
no because the mean is all the numebers added then divided by amount of numbers
but see
x - (x - mean) = x - x + mean by algebra
and x - x = 0, leaving mean alone
so (x - mean) is the difference between x and the mean, correct?
and a negative difference means that x is under the mean
do you agree?
no i don't how could the mean - x equal mean if it's just adding all the numbers and dividing by total amount of numbers
ignore that and focus on my latest group of messages.
ok may i ask a question this is 8th grade math isn't it
Idk what grade this is.
because i missed a that year in high school and they never made me retake it also i am in college now
i basically skipped a grade so i asked to know if i wasn't taught this because i missed that grade
I am unable to answer that for you
ok sorry just trying to figure out why i can't understand this
you should probably ask someone in your country about that. I am only here to aid with the math
anyway, coming back to this
do you agree?
i don't know because almost non of what you say makes sense to me so i don't know
then I apologize, but I'm probably not the right helper to help here (through none of your fault)
I'll step back for others to try.
ok sorry i apologize i just am from USA and was failed by the school system i don't blame them i just don't always get the help i need or needed
Can u send the Question again?
yes
pinned.
ok the problem set is 45.3, 45.6, 46.1, 46.5, 47.2, 47.3, 47.6, 48.1, 53.3, 54.9 and i need to find standard deviation
Well do you know the formula?
no there's no textbook and no one to ask i got my information besides the problem and data from youtube
I will advise Yajant in that two of us have determined that the OP is using the median to calculate (x - mean) instead of the mean.
but I'll let you try anyway
Ahh thats useful thanks!!
if it helps the standard deviation is on my equation sheet
sure show it
i mayhave a different form of formula cuz of regional differneces but ill share it
ok can't find it i looked in my bag i must've lost it
sorry i just found it forgot i put it in my folder
oh okay well share yours then
this is for pure stats
yes and this math is Statistics 3 The Mean and Standard Deviation and Empirical Rule
for ungrouped data we use this
it's a lab seperate but part of my statistics course
we can get the answer with this
no clue i honestly am not that good at this stuff that's why i came her for help
i am good at math but the more complex the problem the less i understand
and she says to just statcrunch everything but that isn't in the lab
well lets go with this
as you were trying smth similar to this earlier in this channel
our teacher literally doesn't teach us how to it ourselves only how to find it using a app
well thats sad
so i assume that you have found the mean deviation?
ah i see
i see have you found the mean ?
well what was it?
If you are a little confused in this method dw, there is another shorter one
it doesn't even apply i already ran out of tried and got a set of numbers\
I wasnt trying to introduce a new method as i thought that you might have made a great deal of progress so
lets use the other method
Here ill share you a Question which my teacher gave to me yest
i will be right back i am getting a call
okey sure
see this one example
seems pretty similar to your Question
( i am assuming you are allowed to use calculators)
different formula though
and keep in mind OP is looking for sample stdev, not population, so his denominator is n-1
um who are you refering to rn?
you
sorry i feel like its N
there's two versions
population and sample
your version is the population version which is N
Um not sure about that
I think its supposed to be N here
Ill just cross check though
Wait isnt the Question For population sample?
@woeful garden is your questuon based on sample or population
Not sure it's based on chickens
!xy
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.
@woeful garden Has your question been resolved?
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Can someone help
,rccw
remember SOH-CAH-TOA
sin = opposite/hypotenuse, cos = adjacent/hypotenuse, tan = opposite/adjacent
try and see if you can use that to solve for these
@acoustic summit Has your question been resolved?
Which question @acoustic summit
@acoustic summit Has your question been resolved?
@acoustic summit dont react ❌ to the bot if you aren't going to ask another question, if you have one that's fine but you should respond or say something
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ive attached the relevant thms/defns. my question is: how can we say that y_k is asymptotically stable, since y_k is the estimation using an RK method for the Dahlquist test eq, so how can we say that it is even a fixed point (ie f(y) = y' = zy, and need f(y_k)=0 for fixed point), let alone say its asymptotically stable. what do they mean
I get that for y_k, an RK approx to y(0+hk) for the dahlquist test eq, we want that our y_k go to 0. But id have thought that just makes y=0 the asymptotically stable point ?
I’m talking about the sentence starting clearly
@smoky hull Has your question been resolved?
Idk whether notation is general so lmk if I can clarify anything in that regard
there appears to be another defn of asymptotically stable i hadnt thought of, but this seems to get rid of dependence on the RK method entirely i think?
what they're saying when they state {yk} is asymptotically stable is that the result you get from the numerical method matches the stability of that fixed point
i.e. take a y0 as in def 8
this will give you a perturbed solution y, which goes to the attractive fixed point y*as y->inf
if you start your numerical method with that same y0, and the solution you get from that numerical method also goes to y*, then it's asymptotically stable
so ur saying if we take the numerical methods sol, then y=0 is an asymptotically stable point?
wait
so a method is called asymptotically stable if it goes to the y* for large k?
oh cant be for large k right cuz they say k in naturals
lemme read what u wrote again maybe im mixing things up
lim_{k->infty} yk = y*
I am talking for large k yes
so y do they say this
i agree with this
cuz were talking about the dahlquist eqs where the only y* is y=0
says for large k?
about the dahlquist eq etc...
ah
I didn't know what it was at first
if wiki talks about it it's general enough
took me a bit more searching than usual tho
i was also wondering that, since this defn S_psi is used for the defn of A-stable, and we kind of define S_psi using that dahlquist eq, does that mean A-stable onnly applies to RK methods being used for the dahlquist eq or is it general
i asked ai and it gave me 2 answers
well it seems specific to the dahlquist eq here
yea
but you could generalize it to other equations surely
dahlquist is a good benchmark tho
i guess but youd be making a new S_psi so does A-stable,, and further L-stable mean smt else
ok what's the def of Psi itself tho
I figured it would be something like that but never seen this exact notation before yeah
tbh
the pset for this wasnt bad
yet to look at past papers though
so ig if i dont actually get it, it should be chill
at least this particular q of mine
yeah they could have bothered clarifying their language here tho
even wiki does better at explaining
lmao
nah iirc ppl said this course was poorly written
had to use a lot of ai assistance to understand where theyre pulling things from etc
hmm
bru i still dont know what they mean by y_k being asymptotically stable for all natural k 😭
{yk} k in N is notation for a whole sequence
ye
they're saying this sequence produced by the numerical method is asympotically stable
as in all the step approx from y_0=y
which I've tried to explain at the beginning
but for a point to be asymptotically stable we need f(yk)=0
and the other condition
u said it goes to 0
i agree
but dont we need exact
and also we need this
i mean if u dont see a clear explanation the notes may well be wrong to call the yk sequence asymptotically stable
well they are wrong not to clarify their statement
which is what I've tried to do
like their "asymptotic stability of a sequence" is related to the asymptotic stability of a fixed point
do they mean like: it is asymptotically, asymptotically stable
idec atp lmao, i think its irrelevant
hope*
idk what you mean with this double asymptotically really
asymptotically it is asymptotically stable
first asymptotically to say taking k to infinity, then the second one as part of the term 'asymptotically stable'
cuz that would sort the issue right?
k->infty is already "asymptotically"
asymptotic = related to limits to infty, that's all it means
ive been thinking theyre saying the sequence is asymptotically stable, as in for all k
cuz asymptotic stability is a term given to 1 particular point
but ig if they mean taking k to inf
oh is this what ur saying
i think confusion in what they meant by just saying a sequence has this property
indeed
ig they mean the limit as k goes to infinity has this property
is what u said asw, now i see
just confirm if this is everything pls, wanna make sure im not overseeing anything
i think so yh?
-close
/close
well maybe you have other questions idk
but as far as this sentence of the book goes I think we're clear
nah if this is fine then im good for now
it's .close
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Calculate for which value(s) of t the vectors
a =
\begin{pmatrix}
2 \
t-2
\end{pmatrix}
\quad \text{and} \quad
b =
\begin{pmatrix}
3 \
2
\end{pmatrix}
are parallel.
lexi
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
oh hello there
It’s probably 5
well since these two are parallel, we can say that they should have same slope right?
Cause I’m supposed to get (2,3)
think again
x1/y1 = x2/y2
Ik what to do
I’ll just have to put the numbers
And do algebraic equation
It’ll be 3 1/3
Yeah!!!
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bro what are these homework 😭
I have like a few more questions too 😭 😭
Its gonna be a long night
Yup
so since its x=0 and y=0 its only differentiable at z=0
Yupp
honestly your solving it rly well i dont think you need help 😭
it looks fine to me as well
i think sirman maybe needs your help


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i thought y = 2z would repsent a side or in this case the diameter. i thought radius would be 2x/2
why does the radius stay as 2x and not 2x/2
wait
is it bc
imma draw it and someone help me
pls
the base of a quarter circle is already equal to the radius right
@jade wraith Has your question been resolved?
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I was trying to find where the xyz of every vertices would be on an equilateral tetrahedron where every vertices is 1 point away from the tetrahedrons center
I got the edge length of it to be ((√57601)-1)/160 but Im not sure if I did something wrong
This is the method used to find the edge length (sorry if it isn't organized)
ok
distance from centre to vertex
so if the distance is 1 point a way then let R = 1
this way you find a
which is 4/sqrt 6
Hmm
so if 4 vertexes are 1 points away, then
coordinate of V1 here will be (0,0,1)
V2 = (sqrt8/3, 0, -1/3), and etc for other 2 vertexes
Mine might be different because its an equilateral tetrahedron
And the center point I'm using isn't at the base of the tetrahedron but the overall center
it is the same term for a regular tetrahedron anyways
Idk
Mb
no problem
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all good man cheers
🍻
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I have recently started getting into mathematics, and I feel I have a half-decent understanding of Algebra2. (Factorials, Summation, imaginary numbers, ect.) And, I need help on what I should work on next to improve my prowis. [Please do Ping me if you respond]
Just follow Khan academy
What is that?
You did polynomials matrices ... ?
Go in order until you see something new
No, I don't beleive I am well versed on that.
At what level would you say Factorials, Summation, and Polynomial Matrices are?
I don't want to press the wrong thing in Khan
⬆️
All those skills are compatable with Trig?
Those are the next things you would learn afterwards
Can we go and change course if it is not on the appropriate level?
Yea
I guess you can check khan avademy as he said
Or if u are well rounded in abstrait algebra enter into linear algebra
Once you have finished abstract algebra, you can move on to linear algebra: understanding how to manipulate abstract objects such as matrices, polynomials, and more.
What would you recommend?
So for example u go from polynomials , fractions, vector spaces, linear maps, matrices, determinants
U can follow this order
In Kahn, or something else?
Yeah... I don't really know what to do here. 😅
I have never seen this anywhere beforehand. .
Where are those skills located at?
Did you watch the videos
Not yet, but it seems ahead of what I am trying to reach for. It feels like taking a desperate leap instead of a dedicsted step. (If you understand what I mean).
Then you need to decide on your own what you want to learn
I don't know about khan academy
Do you know what grade it is typically discussed in?
What are u trying to reach for ?
First year in uni i guess
Which grade are u in ?
A graspable step. I want to grow to have a great foundation of mathematics. I am not looking for impressive problems to solve to appear smart or intellegent immediately. I would like to work in a way that actually builds foundations.
Usually after u finish groups rings and field u can get into linear algebra
Not university....🙃
I am typically placed in classes that far excel what I should at that timw.
Still not really useful information
No one here knows your skills
If you want to do more of the same just google the same topics you mentioned and look for problems
The most difficult work I have done yet: Factorial, Summation, Imaginary Units, complex equasions. Does this help?
Do this
U can either work ur way out by learning theoritically concepts and solve theoritical exercices giving you a solid foundation of as u can say critical thinking i guess (im not good at english)
Or go straight to learning about concepts which help you solve problems
Cause u either go little by little and try to learn the concepts theroitically or go straight to tools whoch can help you directly with exercices
I hope u understand what i mean
Did u do groups rings and fiels ?
Alright then!
I had not yet. Should I start there?
What about calculus ? Where are u at calculus ?
I tried some of it out in primary school. It has been a while since I have done it again, but I have touched bases ever so slightly.
Im not a major in maths tho so maybe you shouldn't lidten to me tho lol im just telling u the order we follow since the maths we learn is kinda advanced for now
But not as a major in maths
The topics are still the same I guess
Math majors just learn them quicker and go further
Ok.
Should I start with the basics of calculus?
Yes
🫡
U need to know some stuff in calculus before getting into more advanced algebra
Is Algebra2 what you are refering too?
*to
Im not sure but probably
I don't the name concepts in english
That's what I was thinking. 😅
Oh
Whats algebra 2 i just went straight to linear alg is it American stuff?
I was saying I had a fairly solid grasp of Alg2.
Trigonometry and Algebra 2 are Precalculus
after Precalculus goes Calculus 1
and so on
So I should start with pre-calc.?
Can you do trigonometry?
If you can you only need algebra 2
Not well...
Did you learn it yet or not?
No, I hadn't
precalc = algebra 2 + trig.
algebra 2 and trig are precalculus basically
and after precalc goes calculus 1
You're welcome
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It's like 9th grade in school I guess?
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How do i derivate this?
Ye but it looks different than the given solution
Let x^2-2x+1 be u and e^-x be v
That is what they gave as solution
There are many reasons why that might be. Did they factor out an e^-x?
Idk
This one would give same results
Well yeah, it’s just product rule. But idk how much his prof simplified afterwards
It is the final sol so yeah should work out
,rccw
You’re off by a negative
When you do the derivative of e^-x, you have to remember to use the chain rule, and multiply by the derivative of the exponent
Yep, and you can choose to factor out an e^-x, and then collect like terms to have a simple, and compact answer
How
Ignore what I said
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Ye freddie explained correctly
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Is the reason why this is only in quarter 1 and 2 is because the angle I is below 1?
Sin always positive in quarter 2 and 1
Ah ok
For this one I don’t know if it will have 1 or two solutions since they add exactly to 180 but those numbers are rounded
Wait let me check
Only B1 is true
Because if assume B2 is true (161.84 degree), then B+A>180, which is wrong in a triangle
And the rest you did correct
So basically, the scenario only works for B1, even though both B angles satisfy condition of quarters
the angle values look gross holy....
Not that bad tbh
25.8 is so unusual
heres a hint
If ur going to convert, convert one not both
or just apply "the" pythag identity directly
s^2 + c^2 = ?
Omg it’s that same identity I keep forgetting
For this next one I know there is some way I can seperate these to get the answer I just don’t know how
missing a - sign
s^2 = s * s
yes, but you want to split it
ahh yea i thought something was off
ghost
and you need to fix your sign ^
yes, but you messed up your sign
you have c^2 - 1 here
(Not 1 - c^2)
which would result in -s^2
how
how are you getting 2 tans
theres only 1 cos in the denominator tho
Thats not how it works
so many things wrong with that
s^2 = s * s
But I thought you had to keep the denominator ?
Huh
they are in multiplication so you dont need to split like that
it happens in addition
ghost
,rcw
I’m just very confused now
^
Because I don’t know what way to do it on my test
yeah
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idk how to progress
Are you doing part a or b
both i am on a )atm
Well it looks like X and Y are independent so maybe we just try do X >= X² first
And then we can just square the probability to account for Y as well
do i have to integrate x and x^2?
I mean
i dont really understand my approach
We want P(X >= X²) right?
Or in other words P(X² - X <= 0) = P(X² - X < 0)
we want the blue area
We can let Z = X² - X and then now consider what the pdf of Z is
There’s a formula that you can derive to find how the pdf of X changes via a monotonic function
Have you learned about that?
no
that the area is the probability ?
That’s the change of variable for the pdf
this is what i have so far
Z = X² - X inverses to X = (1 +- sqrt(1 -4Z))/2
So X² - X < 0 we need to solve this
Err hold up I’m walking around let me sit down
okay:
F_Z(z) = P(Z < z)
= P(X^2 - X < z)
= P((1 - sqrt(1 + 4z))/2 < X < (1 + sqrt(1 + 4z))/2)
does that make sense why
no sorry
I guess i will have to look into this more
think about X^2 - X - z < 0
