#help-0
1 messages · Page 783 of 1
one-sided limit has either + or -
so you said this earlier
@fresh relic
About to test it out
courtesy and common sense in chat, please
Can you please leave I’m being helped in here
Go to a different room
alright sorry
ty for understanding
But anyways @tough hatch for the next set of boxes f(7) = 1 right?
f(7) = 1
Sweet and then for the - and + they’re both 3 right?
Alright and then the double limit is also 3?
not necessarily
any limit approaching x=9, one-sided or not, is indeed DNE
but it also happens that f is not defined at x=9
so yes, they are all DNE
It needs one of the dots for it to be defined right
shaded circles, sure
Alright and then f(11) and the one sided limits and the double limit are all 3 right?
yes
sure
If it is something divided by 0 it doesn’t exist right?
yes
,rotate
?
just use l'hospital's rule
Never heard of it
they likely don't know that.
for (a), that is not right
ln (1+0) = ?
ln 1, of course. but ln 1 is not equal to 1.
what exponent must e have in order to be equal to 1?
is essentially what ln 1 is asking
@fresh relic
What is e
it's a constant
if you have a lim of the form 0/0 or inf/inf then you can take the limit of f'/g' and it will have the same value
pretty neat huh?
,w e^ln(x)
this is e
I have absolutely no idea what that means
ok. you know how sometimes you have to take the limit of a fraction?
And I don’t see a single E in this problem
I don’t
You know the sad part is I took honors precalc in high school and got an A in it
you do not remember logarithms?
I don’t remember anything
I can’t brush up if I don’t even know anything about it
yeah, you will have a hard time dealing with calculus and the above if your basics are not good enough
So like do I just put ln(1+0.5) in a calculator?
logarithms are not uncommon in precal, or in calculus
sure
you did not take any precalculus courses?
you were not taught about logarithms in your precal course, huh
that's just wrong
even a short review would've been helpful
where?
anyone know what my first step would be with this problem? It's asking for the difference quotient but the formula for the difference quotient seems to be different than what's here
this is review, i knew how to do this like 3-4 years ago
@fresh relic
we were i just dont remember
so you're done now?
the value of x
me either, there are a lot of x's here and you're not saying which one
then just copy the given column of x
?so just take 0.5 and move it over?
sure
whats the point of them even including that column?
@tough hatch is this one still occupied
yes
Ok
are you done filling out the tables though? you haven't asked another question yet
I got this
Damnit I forgot about the 2nd table. This takes forever
Is this right though?
1.642857142/1
now multiply the denominator to a number in such a way that the numerator becomes whole
and then multiply the numerator and denominator by 3
recheck
What?
yes and it's big bang all over again
Oh honestly it took too long for the first one I can’t with this anymore I’ll just do the - now
theyre dicks
wut
what value does the function approach, based on the tables alone?
Hello Guys, this is an exercise of my differential calculus, do you know how to answer? I have no idea.
1
Please leave
so that is ur answer
I think
as the values get smaller in the first and larger in the second it comes to 1
this is what is asked of you in c.
alright, sorry for not asking yet
so it is 1?
the first table showcases the values of x approaching 0, from the right side of 0
the second showcases the values of x approaching 0, from the left side of 0
hmmmm...
this isn't a question
but am I picking the right thing
like see in the far right as you go down it comes to 1
thats what ur referring to right?
which?
Both of them
which eventually becomes equal to 1 at x=0
but what does it mean for a fraction to be equal to 1?
numerator ? denominator
=
So for D just put that?
there are certain number of kids in a school. 20% take cars. 3/5 of the remaining students take bus. 612 walk
up to you.
i have given an explanation above.
But why did you say up to you
it's up to you how you write your answer
well how would you write it?
yes
ok so do you know how to do D?
im sorry man im having anuerisms with this i still have more questions
didn't i just say it above?
or I am sorry I meant E
Ok
@fresh relic u good?
local seed = userid*day + userid*offset
is there anyway 2 seeds can be the same if userid is unique, offset is a a number ascending from 1, and day is the amount of days that has passed since 1970 (unix)?
Let the coordinate C be (x,y)
find the distance from A to C and B to C
but since C is on the x axis
y = 0
equate the two distances together
and solve for x
yes although very very very unlikely
ty
like... how unlikely? less than %1
depending on your size of userid, day, offset
sowwy for the dumb question im trying to program and im having a brainfart
an example mihgt be 1231453, 100, 2
anywhere from
explain me linear
oh ok so 0 to around 5-digit number
i little bit dont understand
it could be any number above 18k
although it probably wont ever be
oh now that might have problems with small id number
i think the earliest ids that are active are 10000+
i see, so assuming id from 10k to 1b
id of 10k-100k will probably cause some problems, though pretty unlikely
how about offset?
offset is just how many times the player buys the "next day" pass
so 0 - inf although its not likely to be over 1k
so also unique to players?
nope, almost certain that offset is not unique
ok that might be a problem
day is also not unique
best thing i can think of is, try with your current db
if collision even occurs on day 1 of your db, your seed is pretty bad
so basically your seed should be totally random and equally distributed right?
yes, it should be different for each player
have you tried using any well known hash functions?
if that's your goal of generating random numbers
it has to be constant, thats the only thing
what does "constant" mean here?
e.g if a player rejoins and the function to get their seed is run again
it has to be the same as when they left
with the exception of the offset or day changing
when day or offset changes, your seed must change also?
hash functions should also handle that, using the day and offset as input also
okie, ill look into that

could anyone explain where to start here?
I just asked this today lmao. Ill explain
So we know that f(x) must be contuous
as stated in the question
So that only leaves 9 as a possible discontinuous.
Also note that 6x - 2 = f(9) = -7x + b
cause for it to be continuous it must f(x) must have the same limit value as x goes to 9 from both directions.
You plug in 9 for x
6(9) - 2
which is 52
and -7(9)+b
-63 +b
so 52 = -63 + b
+63 on both sides
b = 115
if @crisp iron can see if I am right.
FYI this is a person
Not the helper ping
@Helpers
Is what you want

Dont want to give them the wrong info lol
if you already know what to do, why are you asking?
i know what the method is called i'm just unsure of how to proceed
i split up the fraction and set up my A + B equation
but one of the variables couls be either positive or negative and im not sure what to do when that happens
this is just $(x^3 - x)^{-1}$
Tra-Guy
and you can use chain rule to antidifferentiate

lol

can you show your current work?
wouldnt it be great to have a reverse chain rule 







IS THERE ONE
technically there is, its just not general

and it only works for composition of linear functions, like 1/(2x+5000)

you have to take $\frac{Bx+C}{x^2-1}$ instead of $\frac{B}{x^2-1}$
Ryuzaki
huh
alos
also*
(x^2-1) = (x-1)(x+1), you can factorize again
$\frac{A}{x} + \frac{B}{x-1} + \frac{C}{x+1}$
Ryuzaki
okayyy i never knew that you could do that
i think i'd benefit more from learning how and why this method works
like when it's to be used

what do i do from here?
i guess OH
pluggin in zero would get rid of b and c
ok hold on give me a sec
@pastel schooner agh i did what you did but i did it backwards and plugged in 9 after solving for b whoops
that should be right i hope?
115
it was!!
thank you!
@jolly stone am i heading in the right direction?

don't forget it's ln|x+1| and ln|x-1|
okee thank you


I could be approaching the problem incorrectly.
But wouldn't it be impossible to have a continuous function given these rules?
the function is continuous if the (existent) limit at x=a is equal to the value of g(x) at x=a
do you see what to do now?
I need to find the value of a in context of the top function plugging in 10 for a
no.
Alright, I'm very sorry but I am confused then.
we are taking the limit of something divided by one of its factors
x-a is a factor of x^2-a^2
because x^2-a^2 = ?
I must cancel out the two x-as
yes, and this works because we are taking the limit anyway
It's important to keep the lim{x → a} when you're working on paper
Obv that's kinda tough here
I'll be honest I'm very confused.
oops sorry
I didnt mean to write that sorry!
so what is it
a+a is equal to a+a
jesus.
Im not sure how else to write that
2a
the original limit was x?
nope.
what is this then?
the limit of x as it approaches a is 10
20
huh?
2a is exactly the limit of g(x) as x approaches a
and you know that the limit of g(x) as x approaches a is 10
so 2a = ?
2a = something
something = 10
(x-a)(x+a)/(x-a) = (x+a)
lim x->a (x+a) = 10
10a?
2a is 10.... ah
the limit of a continuous function is just its value there.
f(x)=(x+a) is continuous over R
so the function of g(z) as x approaches a is equal to 10
the function is equal to 2a
2a=10
so lim x->a (x+a) = (a+a)
yes.
I was about to just show myself out
you crushed me with that joke
oh god I just had the hardest time understanding this but I get it now
thanks for bearing with me and not giving up
Im really hard to work with I know
there are others worse than you
I'm sorry
Hello, our professor gave us a problem that wasn't taught to us
We really don't know what to do
@rotund kraken substituting x = tan^2(u), dx = 2tan(u) sec^2(u) du seems to be like a good idea
or simply, taking x common from the bracket does the job
do you guys know this
let s = 14
then find the least positive solution to t
presumably you want the t value when the ball is ascending to 14 feet
not when it is coming back down
does anyone have chegg here ?
not me
I can only speak for myself.....no, I don't have chegg
aww, thanks man. i just dont know how to solve my mechanics for deformable bodies assignment
it's kinda off math topic more of physics with axial load and shear stress problems. so i really dont think some one can answer those kind of questions here. but thanks anyway
try physics server
definitely can answer things there
until you pass undergrad level work at least it's unlikely you won't be able to find someone who can help
thanks :>
the mode here is small m, and i'm unsure as to how we got that from this pdf
from what i know the mode is equal to the x value of the maximum point of a pdf, but because this pdf is a linear function the single derivative is a constant, and the double derivative is just 0
so i'm not sure how to work this out
heyo i need help dm me if you could help me i would appreciate it if you could help me
<@&286206848099549185>
pinged for this question
wait, what grade are you in?
any constructions of dependent paths with the help of: #discussion message
three transports in a trenchcoat
i don't think channel's latex could help me any further.
Can someone help me out with this question?
dependents path of what? I got lost after clicking the link
here's a small but super helpful skill to learn....try explaining to yourself what that statement means in plain english. Also, your question is a question better suited for the Analysis channel.
if you're familiar with Agda, PathP
oh hmm. Sorry I'm not familiar with that
hey is this channel busy right now?
kind of, is your question quick?
Can't I think of that as like
say we have to choose 8 things from 3 options
then 1st object has 3 options
second has 3 options
3rd has 3 options
and so on
3 options as in, it can be red, it can be blue, it can be green (say)
and I have 3^8 ways to choose them?
Apparently I am wrong https://www.cs.sfu.ca/~ggbaker/zju/math/perm-comb-more.html from this source
choose 8 things from 3 options?
Yeah say I have to choose 8 dogs from 3 types of dogs that kind of stuff
the first dog can be one of the three (say, A, B, C)
no because ABC is really the same as BCA and so forth
wait lemme consume what you said
it all really depends if you want order to matter
order doesn't matter here
okay, then 3^8 ain't it
https://www.cs.sfu.ca/~ggbaker/zju/math/perm-comb-more.html this is what I am following, I kinda need some help understanding why is it so
because 3^8 would count ABC as different from BCA for instance
yea you need to use stars and bars kinda idea aka indentical balls into distinguishable boxes
just another small question, why do we separate it in the example they have
this step (starred in red)
this separation is how we distinguish between the varieties
okay
so basically to make sure order doesn't matter
am I correct?
i dont think I am correct
yea so the order of the dividers and dots matters, but in reality this gives us the unorderdness we want because we are talking about unordered selection with replacement
You're welcome!
does the definition PathP : (A : I → Type) → A i0 → A i1 → Type, where I is the Interval type help?
it doesn't unfortunately. Thanks for trying to help me understand what you meant tho.
what grade are ya in?
if you're familiar with any category theorists here that might understand the query, may you inquire to them for aid?
homotopy foundations.. etc
ohhh. Yea I'm not too familiar with category theory. Maybe you could try asking in that channel tho
how can i check if $1,x,cos(x),sin(x)$ are linearly independent
alef0
7th grade
Yes
I'm 14 in 10th 
so you're 12?
Thanks I would have posted there but I am not able to access that channel somehow
you can visit #get-advanced-access for those roles
Got it. Thanks again!
You're welcome!
this looks kinda tough, ngl
this seems like a math comp problem. Maybe that channel might be better.
Yeah sorry
👍 Got it
how old are ya?
bruh
<@&268886789983436800> see above
Thanks.
wasn't addressed to you, prem
^
oh
kinda funny you brought this up to hahaha
well good thing I didn't join last year when I was a illegal lmao
can someone help me with a chemistry question?
you can certainly try your luck with it
Can someone tell me how to answer these sort of questions?
oh so this is stoichiometry
or is this too offtopic
...wait is this a timed test/exam
no
okay
not a timed test
calculate everything in moles first
ok
there
wym
if its just finding molar mass i can already do that
ok
that'll also be how many moles of H2 will be needed
so do their moles have to be the same
i think i did it
@vale wigeon is the answer B then
seems like it
$$ \sum_{n=1}^{\infty}\frac{(-1)^{n-1}n}{(n+1)2^{n-1}} $$
NikolaJ
How can i find the sum of this series?
We did power series so I assume I have to find a power series that can become this for a certain value of x but I am no sure how to find it here
or if that is the correct approach
x=-1/2 seems like a fine candidate? esp if you reindex the series to start with 0
you have sum[n=1,infty] n/(n+1) x^(n-1)
thanks, I'll try that
I assume I should then either find the integral or the derivative of it?
...maybe? no idea what's best to do here ngl
is this valid?
$$ \sum_{n=1}^{\infty}\frac{(-1)^{n-1}n}{(n+1)2^{n-1}} = 2\sum_{n=1}^{\infty}\frac{(-1)^{n-1}n}{(n+1)2^{n}} | x = \frac{1}{2} $$
NikolaJ
....no, not as written
why?
because I wrote $2^{n-1} = 2^n * 2^-1$ and then just extracted that out of the sum
NikolaJ
but then x is nowhere to be seen in there
...
i don't have enough energy to fix this
is this channel free?
$$ \sum_{n=1}^{\infty}\frac{(-1)^{n-1}n}{(n+1)2^{n-1}} = 2\sum_{n=1}^{\infty}\frac{(-1)^{n-1}n}{(n+1)2^{n}} => 2\sum_{n=1}^{\infty}\frac{(-1)^{n-1}n}{(n+1)} \frac{1}{2^n} => 2\sum_{n=1}^{\infty}\frac{(-1)^{n-1}n}{(n+1)}x^n $$
NikolaJ
$$ \sum_{n=1}^{\infty}\frac{(-1)^{n-1}n}{(n+1)2^{n-1}} = 2\sum_{n=1}^{\infty}\frac{(-1)^{n-1}n}{(n+1)2^{n}} => 2\sum_{n=1}^{\infty}\frac{(-1)^{n-1}n}{(n+1)} \frac{1}{2^n} => 2\sum_{n=1}^{\infty}\frac{(-1)^{n-1}n}{(n+1)}x^n $$
here is the last part that cut off
$$ 2\sum_{n=1}^{\infty}\frac{(-1)^{n-1}n}{(n+1)}x^n $$
NikolaJ
hello everyone, looking for some feedback regarding some questions i have about "Powers of the imaginary unit" specifically simplifying.
Okay
Why is there an x ?
You can't add a constant to this series, it cannot be valid
that x was to turn it into a power series
so when we are simplifying let say i^15 we would find the number that is a multiple of 4 (or closest to the multiple of 4) which in this cause would be 12, then we would do (i^3)^4 which would then become -i, we then multiple that -i by the reminder which is going to be i^3 which finally would = i (-i * -i would then = i) have i got this right?
then find a function representation of that power series and plug 1/2 back into it
I see what you did now
No
Here you would have
i^12xi^3
So its just -i
is that the correct approach then?
apparently im trying to find a graph that looks like this curve....... any idea what type of equation could it be?(except from ecliptic ones)
I am actually not sure
hmm
is this not i? as -i * -i would therefore = i
I haven't looked at these series in a while
ill just wait then....
I don't get what you are saying
i^15=i^12xi^3
That just simplifies to 1xi^3
and i^3 is -i
So the answer is -i
yeah so i was right lmao
No
wait hold on i need to double check
hold on i am just taking a look at my notes, only started this yesterday
hey thanks man you are right just need to double check how to get there, thanks!
also i have another question when we are trying to simplify whatever to the ^i are we always looking for a multiple of 4?
Yh, it is often the case
Even later on in advanced math, you look for powers of 4 w complex numbers
right okay interesting oh and final question, you know how with i^15 we found our multiple of 4 which was 12, and therfore we have to multiple our reminder can the reminder be bigger than 3 for example?
like what if our remainder was like 15 or something or would that not happen?
go to general category-
you ask doubts here
okk thx
Well, in the case of i^15, there is no remainder
I don't really know what you mean by remainder
Usually a remainder comes w long division, but in the case of your questions there is none of that
the remainder being 3 because 4 goes into 15 3 times with a remainder of 3
There cannot be a remainder of 3
We discussed this already
i^3 is -i
I don't understand how you get the remainder of 3
does root 2 times root 2= root 2? Or just 2?
Minh Baka
Can someone please tell me what constitutes as a small angle?
Less than 90 degrees I would assume
as in in the context of the small angle approximations? Depends on what you're okay with for error
at less than 10-15 degrees, small angles are probably good enough for most things
I wonder if he's talking about an acute angle or not
i doubt they're talking about acute angles
But if there's a separate term that is "small angle" that I'm not familiar with then I should probably stop talking
but its just speculation until they reply
"more typically, saying 'small angle approximation' typically means θ≪1, where θ is in radians; this can be rephrased in degrees as θ≪57∘"
I found this on google
Ah, so less than 1 radian/less than 57 degrees?
Depends on what measure you're using
I can't remember what the exact question was but I remember in an exam a few months ago there was something like "Is 278 degrees appropriate for small angle approximation or not?" and apparently the answer was "yes" so is there something to do with a period/cycle??
Or is there only one range for small angles
the reason is that the real angle you're worried about there is 8 degrees
which is absolutely fit for small angle
If you're trying to keep something at 270, then 278 is a small error
270+8=278. If you know sin(8 deg) (using small angle, mayhaps), you can figure out cos(278 deg)
and vice versa
using trig identities
I see. Then what doesn't constitute as a small angle? 
I mean 278 doesnt constitute as a small angle
but it is fit for the small angle approximation
but seriously, something like sin(45 degrees)
would not be very well estimated using small angle
if you're more than 15 degrees from a multiple of 90
you're probably not gonna have much luck
since If I have the trig functions evaluated at x, I can figure out the trig functions at x+90deg , x+180deg, x+270 deg etc
for instance, sin(45)=-cos(90+45)
sin(90-45)?
sorry typo
typoed twice, it is correct now lol
so if i want to evaluate cos(135), and I know sin(45), I can work that out
But 135 is more than 15 degrees away from a multiple of 90
Replace 45 with 5
what I'm saying is that using that principle I used to evaluate cos(135), you could evaluate cos(95), using small angle to get sin(5)
yw
I mean small angle is as good as x - sin(x). For a balancing bot, this is pretty precise even for pretty large angles. For a mars rover, you might never want to use this
can someone help with c
na homework
idk what that means
completing the square puts a quadratic in vertex form
ye
so.. tell me what the vertex is
No, I mean what I said
💀
the turning point
ohhh oh ye
the min/max point, whatever
one sec
$y=a(x-h)^2+k$ has vertex $(h,k)$
Mosh
Maybe try to get rid of the fractions
let me try expand
okay ima do that
i got
do i use quadratic formula
oh nvm
im dum
2x +2 = 0 so 2x =-2
so x= -1
and x =2
can someone help with this
take x^(1/3) as some variable say, "t" and solve the quadratic in terms of "t"
np
Tra-Guy
,w cube root 16
whys it saying x=4096
because it is one of the solutions
bcoz its a solution, as Tra-Guy said
hey guys, how would you attack this?
the answer is ||64 + 31 + 61||
could you pls explain where we got those numbers?
thanks :)
ye ik but i got root 16
cube root 16
ye
<@&286206848099549185>
Is that correct ?
And here is modulas and argument gonna be 1 ????
<@&286206848099549185>
does the question specify that point P has to lie on the line AB?
can somebody tell my what is the answer pls?
not entirely sure
do i need to use the section formula?
yes
can you help with with an example with a?
ill try my best to understand so@i can do the b and c
yes of course
so I'm going to write out the section formula and you tell me if you have learnt it with different pronumerals
Can someone tell if the following is true?
okay!
could you please go onto another channel? we are currently solving a problem here. maybe go onto channel 1
when it says 192 of magnesium do i multiply that by 2 because in the formula magnesium has 2 or is 192 both of them already
same applies to you
.
$P(x, y) = (\frac{mx_2+nx_1}{m+n} , \frac{my_2+ny_1}{m+n}$
Omfish
where m and n are the ratios of the side lengths
sorry it took a while. im just replying so you get a ping to see what ive written
what
this. When a channel is in use, its best to go into an empty channel to ask questions
what do you mean by '.'
i was just replying to your message for you to see
ik
That person is ping replying to your message, trying to tell you that this channel is currently busy so ask in a not busy channel
so which one is correct
its fine its fine
is it free now
we are still in the process of answering the question so no. Maybe go onto channel 8.
$P(x, y) = (\frac{mx_2+nx_1}{m+n} , \frac{my_2+ny_1}{m+n}$
Omfish
is this what youve learnt?
is this multivariable calculus
ok so basically you have two points given to you in the question, A and B with coordinates
uhuh
so A(4, 3) and B(5, 1) these are x1, y1, x2 and y2. So in this example x1=4 y1=3 x2=5 and y2=1
mhm
and then you want to split the length AB into a ratio of 1/3 so the length of AP will be 1/3 and therefore the rest of the line must be 2/3. so your m factor is 1/3 and your n factor os 2/3
so subbing that it
$P(x, y) = (\frac{mx_2+nx_1}{m+n} , \frac{my_2+ny_1}{m+n} = (\frac{\frac{5}{3}+\frac{8}{3}}{1} , \frac{\frac{1}{3}+\frac{6}{3}}{1}$
Omfish
mhm
so the point is $(\frac{13}{3} , \frac{7}{3})$
Omfish
do you remember the rule that loga+logb = log(ab)?
try and use that rule in reverse...
Simplify a and x
I don't think that's the correct use of log properties
it is correct, however not going to get you to the solution
It is if u write it in a fraction
I'm used to fractions, not division signs, my bad
$log_a(a^2 \sqrt{x}) - log_a(x^2 \sqrt{a}) = log_a(a^2) + log_a(\sqrt{x}) - log_a(x^2) - log_a(\sqrt{a})$
It would be simpler to just simplify the powers of a and x before splitting them up again
Omfish
that is correct, however remember to expand the brackets, so that last sign is a negative not a plus
sorry i mean that the negative sign carries out
so the entire second term of the original problem was subtracted, so when you expand that term make sure each piece is minused too
yay!
@vapid oak I have 1 more question
ofc
ahh this is a nice question
It’s says to give exact question
maybe before I help you, what do you notice about the exponents?
It’s has an e
Oh
no
The power of x
Omfish
I remember I used to ln( both sides to solve for it.
But I forgot how to do it
i dont think ln is necessary. Do you understand what I've done here and why it is true?
We have to do it with factor theorum specifically not with long division.
Ye
please go onto channel 7 or another empty channel
Maybe replace e^x with y can help u
That sentence makes no sense, but I guess that you have the idea xd
inaccurate phrasing
Ok cmon
$a^{b^c}\neq (a^b)^c$
Mosh
$(e^x)^2-2e^x=0$ Let e^x = u, then u^2-2u=0$
Omfish
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
somebody can tell me how simplificate this?
please go onto an empty channel to ask this. this channel is currently in use
I got u= 0, u =2
you want to apply ln to both sides
so if e^x = 0 we get x=ln0 which is undefined
e^x = 2 we get x = ln2 which is our answer!
What do u so after this
apply log laws
so you bring the exponent to the front of the log.
x * lne = ln2
but lne = 1
so x = ln2
my pleasure!
Sounds like a person who works at Chick fil A(if you know what that is)
@tawny lion try using induction
how would I do that?
but my question is regarding i)_
Let's see
You have a interest rate of I so our ammount after a month is P+P*I/100
Then there is the repayment so the amount is reduced by R
right
So you have S1 the ammount for the first month
it would be $P(1+\frac{I}{100})^t - R$ ?
Then you take S1 as the initial ammount to find S2
kurama
what is t
no
