#help-0
1 messages · Page 1039 of 1
No
no no it's from pi/2 to 2pi
yes
ig its better to use some identities
$tan(\frac{\pi}{2}+x)=-cot(x)$
$sin(\frac{\pi}{2}-x)=cos(x)$
∆y/∆x=πy+π^2x
so we are in the 2nd, 3rd and 4th quadrant, but since sin is positive cos is negative
so it's in the 3rd quadrant
is sin positive there?
i mean second
yeah
.close
Closed by @slender sparrow
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
hi guys, how can I solve this differential equation?
what have you tried
I got these solutions{cos(3x),sen(3x)} from y''+9y=0
using the incomplete DE method
then, I can say the general solution is y = C1.cos(3x)+C2.sen(3x)
now missing the particular solution part
In this section we introduce the method of undetermined coefficients to find particular solutions to nonhomogeneous differential equation. We work a wide variety of examples illustrating the many guidelines for making the initial guess of the form of the particular solution that is needed for the method.
"guess"
hmmm
but I have a sum of functions of g(x)
sen(x)-e^(-x)
do I need to solve 2 times the DE?
y''+9y=sen(x)
and
y''+9y=e^(-x)?
and then add up the 2 yp?
yea go through solutions in example 10 here
https://tutorial.math.lamar.edu/Classes/DE/UndeterminedCoefficients.aspx
In this section we introduce the method of undetermined coefficients to find particular solutions to nonhomogeneous differential equation. We work a wide variety of examples illustrating the many guidelines for making the initial guess of the form of the particular solution that is needed for the method.
Closed by @mild copper
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
hey guys, can you help me out with this. Is this true?
is c a point or a domain?
Does it really matter?
what does your intuition say ?
Not really lol
Just wondering what c is exactly supposed to be
no
c is obviously a point because it's one of the 3 most common names for points when talking about continuity, and it definitely isn't a good name for a domain
are you sure about that ?
As far as I'm concerned
Well
I guess if like
Well now that I think about it
Not always
that's an example yes
I was thinking of something much more drastic but hey, this works
like $f(x) = (-1)^{1_{\mathbb{Q}}(x)+1}$
which is continuous nowhere but whose absolute value is continuous everywhere
themateo713
I mean (-1)^x by itself satisfies
the problem is you have a function whose domain has no interior
so talking about continuity for f(x)=(-1)^x is .... Rather uninteresting
your example is almost the simplest yes of course, but not the most interesting/enjoyable
that's also quite simple indeeed, though I had in mind f(x) = 1 if x != 0 otherwise -1
@reef lantern Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
This is from Oscar Levin's open Discrete Mathematics book
The answer for B and e are 6720 and 6660 respectively according to the show answers button
Question is : how do I even begin to get the answers for these? I'm actually totally clueless
Closed by @junior talon
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
8 letters total
8x7x6x5x4
Equal 6720
Calculating possible combinations while removing one from each multiple to account for 1use letters
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Could somebody explain me this please?
I get the limit on the left but what to do about the cos?
cos is in [-1;1] so it doesn't matter regarding the infinity
thank you!
.close
Closed by @sterile vale
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
HOW?!
@alpine sable Has your question been resolved?
Closed by @delicate egret
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
How..?
it feels like you cut out way too much from the image
^
what's the context exactly and what are you confused about?
but I feel it's a u = -t sub considering the bounds
not sure why they went with the same variable for the sub though
so I might be wrong
oh is a a function
I'm just a little confused about the 1st part although by graph I can easily see they will both give the same result
I think it's this
oh wait you're integrating that
oohh
that clears up a lot
yeah it's an even function
since $e^{-2a|t|} = e^{-2a|-t|}$
Doggo
then you can just write it as 2 times 0 to infinity of that function
yes but how is this done? :\
Or is it just using the even property of the function
you mean how to integrate that function?
No, I was confused on how the limits changed and thought it must be some property to change them that way
I know this is very silly
if we ignore the fact that it still uses t as the variable, this sub does give you that integral
since as t -> -infty, u -> infty
and t = 0, u = 0
then dt = -du
so you have negative to flip the bounds
and you get that integral, but the variable is u
Hmmmmm
@alpine sable Has your question been resolved?
Closed by @delicate egret
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
What would the identity element be?
Since we dont know what G actually is
you can give the identity of G a name (a natural choice is 1 or e or 1_G)
Ok, so just call it e then
Also we know G is a group so we know G has an identity element.
But how do we prove the identity in (G', *)?
Take a in G' (or G). Then just stating that ea = a = ae?
Feels kinda weird
since there are two different operations here, you should specify which one you are using:
$e\star a=a\cdot e=a$ etc
Toby
but your idea is right
Closed by @neat sierra
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Complex Variables:
Attached is the problem and the theorem it is referring to. I’m not sure what I am being asked or were to start.
I do love Euler's identity
I would probably love your help then 🙂
I wish I could, but this is beyond my current capabilities at the moment. Sorry!
Just a fan of r*e^(i*theta)
<@&286206848099549185>
@edgy flare Has your question been resolved?
<@&286206848099549185>
@edgy flare Has your question been resolved?
@edgy flare Has your question been resolved?
Hey poisoned! More CV?
you'll probably have more luck posting this in #real-complex-analysis
@alpine sable I asked about posting a homework question there and someone told me it did not belong there.
nah it's fine
people in help channels often come for hs math
if you want help for undergraduate courses you'll likely find it in ''early uni'' or ''advanced''
.close
Closed by @edgy flare
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
So im alittle bit confused, i get that it wants to me to get v_x and v_y
So it wants me to do DX/DT
that just comes out to 4d-dt/3d
seperate it out find the x component of velocity at the given time similar for the y component
Which is very handy actually it comes out to be
Oh no oops
how do I do that?
I got this
and i know its wrong
but i also dont know how to make it not wrong lol
the examples just kinda snap to a solution, it doesnt show me what they did
This is terrible I think you don't know how to differentiate
differentiation of x component of velocity which is 3t would be 3
which is constant similarly you'll get the y component velocity which will be -1
Now take the magnitude and it comes out to be root 10 super apologies I don't know what I did before but
root 10 is correct
So do I not need the whole v_x=dx/dt equation?
its the same thing
okay so to backtrack, why is X a constant?
So I dont set T to 3?
which x 3 is the constant you have to differentiate 3t
Normally you would after differentiating but as you can see the velocity is not a function of time and hence constant
differentiate it one more time and you will get the acceleration 0
How do I know its not a function of time?
because after differentiation You got a constant
re-read this
wouldnt it equal 3d?
That's not how we do differentiation
use this
okay, so how does v_y come out to -1?
along the lines we used last time it should be 4
or -4
same way , no
its 4 - t differentiation of a constant is 0 here 4 - t will come out to be -1 which is the coefficient of t and if you apply the formula you'll get it remember you are differentiaing with respect to t so if no t the answer is 0
ok, i think i get it
This was the answer to be clear
okay the rest of the formula is alittle easier to understand for me, sqrt v_x^2+v_y^2
yes
COOL I finally got past the first questions!
TY!
9 more to go by tomorrow and i can have a weekend lmao xD
u rock!
Good luck and learn differentiation ,for your own good
Lol im trying, I just got the handle on derivatives last week
😄 tc
okay so to see if i understand this, in this case v_x would be 4 and V_y would be -1
Yes but you have to find the acceleration for which you have to differentiate one more time
which gives you zero
ok the acceleration part lost me, what do you mean by that?
why would it equal 0 with acceleration?
Alrght
sorry 😅 im alittle hopeless with calc, it loses my frequently
this is the relation
differentiating position one time will give velocity as velocity is the rate of change of position
differentiating velocity will give acceleration
So differentiating the position two times will Give you the acceleration
A short Video on this topic will help I think
Do watch it
Here r is position , v is velocity, a is acceleration
d/dt just denotes the differentiation with respect to t
is there a video you would suggest?
Thanks to all of you who support me on Patreon. You da real mvps! $1 per month helps!! :) https://www.patreon.com/patrickjmt !! In this video, I discuss the relation about position functions, velocity functions and acceleration functions. I go through the mechanical process and discuss the relationship a bit more in depth at the end.
For mor...
Explains with an example
If we are going to study the motion of objects, we are going to have to learn about the concepts of position, velocity, and acceleration. More scalars and vectors! Once we get this stuff out of the way, we can really get cooking.
Watch the whole Classical Physics playlist: http://bit.ly/ProfDavePhysics1
Modern Physics Tutorials: http://bit.ly/...
explains what is position,velocity,acceleration
so v_x and v_y is showing velocity?
so to get acceleration i take the second derivative
so it would just be x and y equal 0
oh boy that was more complicated in my head
Cool ty! I'm rolling now!
.close
Closed by @wintry vortex
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
ugh, I thought i got this one pretty well and somehow the degrees arent right
so i got the magnitude, then i used tantheta=-1/5 to find the degrees like the example says
am i missing something?
did you set your calculator to DEG?
yes
I dont need the answer, just confused on why its not right 😦
I was super confident on that answer lol
well, if your magnitude is correct, then your angle is correct. could enter -11° or 349° instead 🤷♂️
the magnitude is correct, it already told me its right
WHY WAS 349 degrees right?!
Closed by @wintry vortex
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
.reopen
✅
sorry didnt mean to closewhile u were answering 😅
np. be careful with the quadrants when using arctan 😉
Closed by @wintry vortex
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Too tiny to read this resolution
Let me fix . one sec
I need to know what each variable means v
Can anyone help? <@&286206848099549185>
You are posting more than once problem
I deleted
@humble prairie Has your question been resolved?
.close
Closed by @humble prairie
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
good evening, can you help me with this simplification of radicals
which one?
Frosst
a little
what do you mean a little
you either know this or you dont you cant know a rule a little
the basics
Closed by @proven saddle
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
I'm not sure if 14 is correct. I double checked my work but it was wrong 
A Quonset Hut's height is its radius.
The volume of a Quonset Hut is the second picture
show your math
i'm not sure how to go about the problem
i plugged in the values but i dont think its how i'm supposed to do the problem bc when i double checked i got 7389 instead of 7540
gimme a sec sorry

swap your h and l
why would it be larger than 7540
i honestly have no idea 😭
use a calculator
try it again
this is how I originally did it; not sure how it’s wrong 
By swapping the h and l do you mean the values?
nevermind! i got it correct!
.close
Closed by @lethal sinew
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
The function f has the property that for each positive integer n, the number f(n) is also a positive integer. It is also known that f(n) + f(f(n)) = 2n for each positive integer n.
Find all possible values of f(1000).
Can someone please prove that the only answer is 1000?
@daring tulip Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
I did this and got some nonsense... I must be doing something wrong, but I'm not sure where
your 2 looks like a z
also no you didn't get nonsense you got exactly what you were supposed to
the numerator approaches a positive number while the denominator approaches zero
perhaps you could argue the denominator x(sin(x)-sinh(x)) ought to approach zero from below and so the limit is -∞ rather than just nonexistent.
...
,w graph y=sin(x)-sinh(x)
oh! Then I guess we are supposed to prove by definition that the limit is infinity...
okay thanks I'll do that
.close
Closed by @grizzled vortex
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
.reopen
✅
So the right limit and left limit is both minus infiniity, right?
yes
Closed by @grizzled vortex
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
help
pointing back at the problem isn't going to help us help you at all
are we to understand you have no idea how to even begin this problem?
There's no math yet. Set up your physics equations
Closed by @oak fiber
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
can i just post it here?
yeah
Mhm
what have you tried
Yes
umm no
Any epsilon
you can NOT set e
I can pick epsilon = 0.5 and your set won't work.
so for example, it doesn't work for e = 0.5
right
If your set S is {1,2,3}, then max(S) = 3
So set epsilon ≥ 3 (epsilon can be anything ≥ 3), and this is your example. S is also a subset of R+
what you want is a subset such that if i pick any epsilon > 0, there exists an element in that subset that is smaller than that epsilon

right that's what confuses me
because epsilon can be .0000009
so i was thinking the empty set
as one example
There's a pretty cheeky choice of S listed in the problem..
well, there's no element in the empty set that is smaller than e =1
You can also consider infinite sets in general.
so you might try an infinite subset!
you can think about why no finite subset satisfy this condition later
ohhhh
You can also try and construct a set that works from a finite set that doesn't.
so can i since all integers are part of all real numbers
can i just take the set of all postive integers
no positive integer is smaller than e = 0.5
fucking a
lol
so e can just be any real number huh
yes, bigger than 0
is 0 part of the empty set?
here's a hint, do you know about sequences?
mhmm vaguely
Try this use S={1}, I pick e=0.5, so you say "Damn! I'll pick instead S'={0,0.5}" then I pick e=0.25 and you do what?
ooh, try doot's idea
mhmm okay but just one thing
S has to be all positive real numbers right
so it can't include 0
Yeah
yes
right
But S' cannot contain 0
Lol
so if you pick .25 i pick .25 then you pick .009 and i pick .009
and we gon forever and ever
S'={1,0.5} is what I meant.


I'm thinking S is then R+ itself
That could work ig
Yeah but 0.09 is ugly what if I pick something easier like e=1/8 instead lol?
Then 1/16
Then 1/32 and so on.
This was the cheeky answer I mentioned lmao
But does fear see why?
Oh
try to construct more following doot's example
xD
so doot did
{1/1, 1/2, 1/4, 1/8, ...}
0 < 1/n ≤ 1 for any positive Integer n
right
Positive integer n
okay i just put all real numbers for my first example
time to use the old noggin

Fear just focus one more time on doot's pattern
All reals won't work
How so 
It has to do with props the q says S must satisfy.
Answer was given in #discussion
All reals is real close ur just mixing up the q
For ex -1 can't be in S according to the q.
that's one example that we've also given
Yeah all positive real numbers will work
partial answer only, it was mostly to make sure you understood how what you were saying was wrong
Can I give one more example
I already said it like two times
Are you just here to gloat?

but R+ works right
all positive real numbers
okay just making that clear
yeah because S can be a subset of R+
and all positive real numbers is a subset of itself
nice

Yeah, and if I pick epsilon>0 by density you can pick some real t between my epsilon and 0 too ofc.
Or just midpoints or whatever
There's multiple ways to pick t lol.
the key here is to have a subset that can contain arbitrarily small elements
There was nothing special about the right endpoint here
for the other example i pick, epsilon can still be any positive real number right? AKA .00009
Yeah
Fear what do you think about doot's example on S = {1/1, 1/2, 1/3,...}
Yeah that would work
Nice

can you reason a little why that would work?
But there are simpler ones feeds is trying to lead you to.
well
i was thinking about it before
but
i thought about
R+
and all irrationals
but when you said R+ worked
it made me think maybe irratoinals work
since we don't really know the smallest irrational
Mmm so there's a property I mentioned earlier about R^+ that the irrationals have too.
But try feeds's example it's good lol.
mhmmm i know this pattern
lemme see
What can you observe here
it's getting infinitely smaller
Hence you can take any epsilon, where there will always exist some element s ≤ epsilon
Can you write it out as a sequence and take the limit?
ohhh shittt
mind blown
Fear do this
U might see it better if u do
for the irrationals?
Because really we're just doing that.
No no for the other examples
We're just tossing sequences at you basically.
right
okay i see now
i was confused at first
i thought u meant small elemtns as in
a small number of elements
i see it's now the value of the elements themselves
to be small
You just like need at least one element in S, where if I say any epsilon, your set will always have some s where s≤€
right
and since the example 1/1, 1/2, 1/3 will get infinitely smaller
it will work
Yes
essentially i guess i'm a person that has to KNOW the values
so when it comes to stuff like this
where we don't know the smallest number
i suck at it
You'll get used to it gradually 
Now you can give 1000 examples instead of 3

alright then i'm gonna make the set of all irratoinals as my second one
and for the third i'll go with the 1/1,1/2
The bottleneck is your wrist endurance
Harmonic
So like here's one way to do what riemann said take arbitrary elements out if this to produce a new different example set.
S = {1/n : n is a positive integer}
Here's another way. I divided 1 by 2 repeatedly here.
So pick a different integer larger than 2 instead.
Find the 3 answers that take the minimum amount of writing
right i should've thought of that
since it's greater than 0
any infinite fraction sequence
will satisfy it
In this prob you really just want inf sequences that have all pos terms and converge to zero
The one in #discussion was $(0, \infty)$
riemann
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
For ex 1/n! works too
R+
(R+)\{1}
(R+)\{2}
we didn't cover any infinite sequences yet so i was confused
but good to know
i'm getting a head start on this hw

is this actually legit?
Ye
Yes lol
smh
idk why i think the answer is harder than it is
i just got raped in linear algebra and diff eqs
it's alright, our sequence approach is more enlightening
There could be more than one answers.
yea you guys helped a lot
So you can go for the harder or easier one.
thanks for real
It's upto you lol.
no problem


$(0,1), (0,2), {x \in\R^+ \ | \ x\notin \Q}$
riemann
Yes
It means you excluded {1} from R+
Like say in a Set S you have {1,2,3}
Then S\{1} is {2,3}
Exclusion
xd

@obsidian kayak Has your question been resolved?
Closed by @obsidian kayak
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
How do I do question 5?
write out all possible outcomes and the resulting totals in a table
I didn’t know how to write it in table form, so I used tree diagrams
ok sure you can do a tree diagram if you want
you're rolling two dice, and you ignore the second dice unless the first rolled 1 or 2
Yes
\begin{tabular}{c|cccccc}
&1&2&3&4&5&6\
\hline
1&2&3&4&5&6&7\
2&3&4&5&6&7&8\
3&3&3&3&3&3&3\
4&4&4&4&4&4&4\
5&5&5&5&5&5&5\
6&6&6&6&6&6&6
\end{tabular}
Ann
Yes
do you understand how i constructed this table?
11?
We did something similar to this
How’d u get 13
wait, hold on. we were both wrong.
it's 19.
3 in the first row + 4 in the second + 6 in the fifth + 6 in the sixth
how many ways are there to seat 5 people at a round table?
24 ways
and in how many of these ways are the people seated in order of age (cw or ccw)?
That’s the part where I don’t know how to calculate it
sounds like you're overthinking it
bc there's only two such arrangements
youngest to oldest cw and youngest to oldest ccw
that's it
what is that number meant to be?
How many ways 5 people can be seated around a round table, considering both clockwise and anticlockwise.
then this not only makes no sense but also is not what the problem asks for.
Yea Ur right it makes no sense
What does ccw mean
counterclockwise.
@opaque inlet Has your question been resolved?
Closed by @opaque inlet
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
im getting the correct answer through lcm removal technique, but im not getting the correct answer through period reduction
@tribal oxide Has your question been resolved?
@tribal oxide Has your question been resolved?
@tribal oxide Has your question been resolved?
@tribal oxide Has your question been resolved?
its alright i can wait
Hello, I'm not really comfortable in period reduction at all so I'm sorry if my help is futile.
However, it seems that if you make a linearization of the cos^4 term, the expression of f(x) is easier
Maybe that doing a period reduction is easier with this ? I hope it is x)
what is linearization of cos^4
but what ur doing here in the end is, what in my class the teacher calls it "avoiding lcm technique", manipulating f(x), so the fundamental period can be easily found, as taking lcm is where the problems between period and fundamental period comes
which i have also done in this, maybe not with the linearization of cos^4 term, but in a different way
as idk what linearization means
English is not my native language so I'm sorry if the explanation is messy. The thing is you express a cos^4 term with a sum of cos^1 terms and a constant.
It's the same process that gives the formula cos^2(x) = (1/2)(1+cos(2x)).
Here I just did it with a higher power. You can obtain these expressions using this formula:
but in class, we were taught a different technique where say P is the period of of a function, like say f(x)= sinx + cosx, then the individual periods are 2pi, 2pi, we take lcm (2pi,2pi), which is 2pi, and then we divide this P by every prime number and check if any of those work as the period, and if something matches, then that becomes the new P and we divide it by every prime number and so on, its usually only helpful if theres options in the questions, or if the conditions in question, which make elimination easy,
I see, I'm sorry that I can't help you more, I just saw that the expression could be simplified and I thought it could maybe help...
Yes it is, there are actually two formulas, called Euler's formulas that are deduced by the relation e^ix = cos(x)+isin(x)
basically i want to prove f(x+ 2(pi)^3)= f(x)
it does help, your technique gives the correct ans
I tried to find out cos^4(x)
Im getting this
Now i have to replace x?💀, Or maybe this can be simplified further
That's it, and then you need to make another use of the formula to get this result:
It's really useful because you can get formulas like that for any cos^n with n a positive integer
i understsnd your process now
but can you help with this
while using the original form of f(x)
Yes I get it now, it's easy with the expression I got, I'm searching for the original form of f(x)
Alright, so first thing: I see that you tried to break fractions within the cos^4 the cos terms into sums of 3 other terms. Because you want to prove f(x+2(pi)^3) = f(x), I would advice you to break the fractions like that:
Here I wrote it for the cos^4 term, you'd need to do the same thing with the other cos term
And then, using angle addition formulas, I think that you'll be able to find back f(x)
i just noticed
once we broke away the pi/2 term
we cant join it back anymore?💀
because the lcm of 4(pi)^2 and 2 doesnt exist...?
but then again i am assuming that
2pi^2 is irrational
but im not very sure abt that claim
You can multiply numerator and denominator by 2(pi)^2 and join it back can't you ?
right.., im probably thinking too much
basing things of a childhood concept, so im not very sure
ill look into it, once i finish my current workload, thanks for your help tho
.close
Closed by @tribal oxide
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Np, don't hesitate to reopen if you need more help
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
This is the graph of c part .I don't know how this was done
It is a unit impulse signal btw i.e δ[n] = 1 for n = 0 and 0 for every other n
Do you know how to find n such that n-4k=0?
@alpine sable Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Can anyone see what I'm doing wrong here?
,rotate
Hard for me to read but trig sub if thats what your doing your good
@gaunt eagle Has your question been resolved?
,w integral (x+1)/sqrt(1-x^2)
Your integral of 1/(1-u)^(1/2) should just be solved with power rule
but you could technically also use a trig integral to solve it, right?
by using u^1/2
why not?
Differentiate it and find out
Closed due to timeout
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
What did I do wrong?
you randomly used the point(3,2) for some strange reason
Closed by @cyan mountain
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Factor $-a^2b^2 + 2ab^3 - b^4 + a^2c^2 - 2abc^2 + b^2c^2$
But I don't really see what I can do after that
Hints only please.
write it like $(-a^2b^2 + 2ab^3 - b^4) + (a^2c^2 - 2abc^2 + b^2c^2)$. can you factor something out of the first and second term to get something nice for each one?
Denascite
@thick lynx Has your question been resolved?
Hmm
b^2 for the first one, c^2 for the second one
But it still wont be very nice?
$$-b^2 * (a^2 - 2ab + b^2) + c^2 * (a^2 - 2ab + b^2)$$
Kepe
those terms should scream "I am nice" into your face
Kepe
also they are the same which is extra nice
so it's
$$(a - b)^2 * (c^2 - b^2)$$
Kepe
yup
Closed by @thick lynx
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
pls help
@hollow fossil
@hollow fossil Has your question been resolved?
i dare you to try it. its insanely complex
Definitely is, but still doable.
Just with the rule you can compute the limit.
Now you have to brute force it, that is a different story.
I didn't look into other ways.
But just with the rule I did get th answer and then left.
So yeah unless this is preparation for some exam which requires you to solve this in very less time use the rule.
Or if you simply want something else, people will of course help you.
I have absolutely no idea how you’d go about this without l’hôp
Do you have any kind of indications from a teacher or something?
If not I’d just hold my breath and use l’hôp
Lhop is le hope here i think
@hollow fossil I have done it for you. You only need to apply L'Hospital Rule 2 times.
(but before posting my answer, please submit your answer here first)
here it is :)
nice :)
woah which app do you use to get it like that?
in a digital form
Microsoft word
ahh
"Alt" + "=" for equation func.
You can also use LaTeX for mathematical notation, but I usually use MS word to sketch my work since it is faster for me to write something.
i see. its been so long since ive used word haha
anyways thanks for the help guys :)
My pleasure!
Closed by @hollow fossil
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Hi
What's the meaning of the notation x belongs <3;6>
Does this mean that both 3 and 6 are have opened boundaries
Send context
So both 3 and 6 are excluded from the interval ?
Does this mean that 3 and 6 are excluded from the interval in which x lies in
Where is this from? Doesn't look like standard notation
I'd read it as $x \in ]3, 6[$
illuminator3
Idk someone sent me this exercise and needs help but it's the first time i see this notation
I read it like that
I'll read it this way
Not [3;6]
Thank you so much for your info
it looks like "x is smaller than 3 or bigger than 6"
No it's open interval
] is used for (
In some places.
]3,6[ means (3,6)
Or so I've been told.
the french use outward-pointing square brackets for open intervals yes
<> is closed interval at leasz in notation i was taught
this notation varies by region
It does. And yes I was talking about French notation.
So is <> closed or opened
Yea ik this
I am just talking abt this bc the one who asked the question had the interval in this form so I want to know what to answer him
best see your textbook about that
Id say closed
Which textbook
It's not my question
Someone sent me a pic of the question
Same country?
What country is he from?
oh so it's actually a game of broken telephone...
i've seen angle-brackets used as closed, and also used as open, and also used as intentionally ambiguous
so we really cannot tell
this is NOT a math issue
this is a language issue
XDDD
No it's just the inequality I sent
It's easy but I wanted to know the notation just
I want to be sire of something small here
I thought language of math was universal
notation varies by region.
Some countries dont even use base 10 numbers
Fr?
Idk if they learn base 10 in school or do math in other bases
Preferably yes
Closed by @tepid drum
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
stuck in c
You can calculate the lowest possible value of LHS to be 4 using parts a) and b)
Closed by @sullen dock
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
is the answer to this x^2 + 16x + 64
or x^2 + 64
yes
Closed by @hot bison
Use .reopen if this was a mistake.
Please take a minute to participate in [our survey](#changelog message) if you haven't already!
@hot bison i meant the first 1
ok
x^2+16x+64
ok



