#help-0
1 messages · Page 458 of 1
Yes
split the single series into two
a2n = 6 + (n-1)9
a2n+1 = 1 + (n)9
thanks for the first question :) ill just wait for the 2nd one now
the differnce is ap
@marsh sedge Has your question been resolved?
so like write a bunch of an - an-1 n add them all up
can you elaborate? thank you. was this for question c? because b is fine
a2 - a1
a3 - a2
...
an - an-1
add them n ur gonna get something
would it be correct to write the formula for letter c as an=(an-1)-(n/3)?
@marsh sedge Has your question been resolved?
.close
Closed by @marsh sedge
Use .reopen if this was a mistake.
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 me bro
to eliminate y, you have to use the fact that total surface area of the brick is 600cm^2
ok and
idk what
to do with that infomration
all i can make is an equation
that has y in it
you know how total surface area is calculated?
exactly
set it equal to 600
and you'll get another equation in terms of y and x
form here you can get the value of y
and substitute that in the expression for volume
yw
.close
Closed by @brisk spindle
Use .reopen if this was a mistake.
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.
okay this is kind of embarrassing but can someone help me rediscover why my argument works
Back when I wrote this, it made perfect sense in my head
now I barely even remember what bezout's identity even is and most concerningly I don't understand why gcd(2, k) would belong to the ideal
it's possible that the proof is flawed to begin with but I vividly remember that it used to make sense to me
@left wharf Has your question been resolved?
bezouts identity says that there exist integers x,y such that gcd(a,b)=xa+by. so the gcd of the two numbers a,b can be written as an integer linear combination of them
as ideals are closed under integer lin combinations, it follows that if a and b are in the ideal, then the gcd also has to be
I want to point out that you can make the argument much quicker. the number n has to be odd, so gcd(2,n)=1 immediately, as 2 only has the factors 1 and 2
@left wharf
I get that, by why is k in the ideal
this makes a loooot more sense though XD
and that generalizes too, because if you add something to the ideal (p), then it cannot have p as a factor, and therefore gcd(p, n)=1, and bezout lemma says that you have a linear combination of p and n that gives 1, so therefore 1 is in the ideal
ohhh shit I'm dumb
yeah now I understand the original argument too
oh I didnt even catch that. yeah that doesnt immediately have to be true
of course it will be true because the ideal turns out the be all of Z
gcd(2, n) belongs to the ideal because of bezout and therefore gcd(2, k) also does and that's the argument
but yeah it's dumb I'll rewrite that according to your suggestion, thank you so much
thank you a second time this is very cool
.close
Closed by @left wharf
Use .reopen if this was a mistake.
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.
excuse me how do i write limh->0 inside word
There's probably an option to use math symbols in it
they have limit right there
Closed by @strange fractal
Use .reopen if this was a mistake.
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 to get the slope of the line l we get the derivative of 2^x which is (2^x)/ln(2)
Then sub in x = 3 so we have (2^3)/ln(2) = 8/ln(2)
Shouldn't ln(2) be multiplied instead of divided?
Yep
Then we do the same for 3^x, giving us the slope of line l 9ln(3)
So then to get the slope between them we use arctan
So its arctan(9ln(3) - 8ln(2)), right?
Which is arctan(ln(3^9) - ln(2^8))
There's a formula for the angle between two lines, but honestly I don't remember it at the moment
arctan(ln((3^9)/(2^8)))
Is there something else im getting mixed up with?
Cause I know I remember using arctan to get the angle between 2 lines or something
I can only suggest you to revise your lecture notes, probably the teacher has told you something about this kind of exercises with arctg
I will find it 1 moment
This one
First you take arctan of the slope of l, which gives pi/6, then you take arctan of k, which gives -pi/6
pi/6 - (-pi/6) = pi/3
Yep so arctan(9ln(3)) gives 84.22 degrees and arctan(8ln(2)) gives 79.78 degrees
Which is the answer they wanted
I knew I wasnt crazy 😂
Thanks!
.close
Closed by @warped topaz
Use .reopen if this was a mistake.
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.
f(x)=(x^3 + 2x^2)/2x differentiate with respect to x
hello
do you have a pic of your work,
its a bit hard to read that
missing ^2 at the end
and ideally you should also put () around the denominators to avoid ambiguity
and also
you haven't actually differentiated anything yet
so very inappropriate to put dy/dx =
all it seems you've done is split the fraction so what you currently have would still be f(x)
dy/dx= (3/2x)x^2 + (2/x)x
no
how are you getting that
are you able to draw your work on paint
or display it on something capable to typing/displaying math like desmos
what is the answer?
we don't just give out answers here
$f(x) = \frac{x^3 + 2x^2}{2x} \ \
f(x) = \frac{x^3}{2x} + \frac{2x^2}{2x}$ \ \
simplify each fraction
ℝαμΩℕωⅤ
Closed by @frigid ore
Use .reopen if this was a mistake.
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 author makes these claims in succession (besides the written claim of mine at the bottom), and the point is that I have zero clue as to how (a, a] is an element of C. I fully understand that the empty set is equal to a set (a, a], but by definition of c, we must have the left bound less than the right bound for any interval in C. This is clearly not satisfied by (a, a]
!original
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.
Ok
Sorry kinda big picture for continuities sake but the circled parts are what I specified
ok ic now
this looks like a misunderstanding
a semiring is a collection of sets
so C = (a,b] isn't right
I understand that C is the collection of all sets that can be written like that with a < b, yes, that was handwavy
But no set in C would be (a, a]
well (a,a] is in C
or i would even say, (0,0] is in C
C contains all intervals of form (a,b], where a and b are any real numbers
so that includes (0,0]
No it doesn’t, there are restrictions on a and b and one such restriction is that a < b. Surely that’s not the case and I’m wrong but it seems like that’s what every set in the collection has to satisfy
that's not a restriction on the sets in C
that's something inside the definition of the sets that are in C
a and b can be anything
(0,0] is empty because there are numbers x with 0 < x and x <= 0
$\mathcal{C} = {(a,b] : a,b\in\bR}$
:bending_skull:
right from the definition, (0,0] is in C
$(0,0] = {x\in\bR: 0 < x \text{ and } x \leq 0} = \emptyset$, right?
:bending_skull:
C is the collection of sets of form (a,b] where a and b are real numbers
setting a and b equal to whatever real numbers you want gives you an element of C
due to this condition, (a,b] might be empty depending on what a and b are
but any set of that form is still in C
even if a = b
But then if you can contradict the definition, why not make b < a? What is (3, -7] supposed to mean?
that's also the empty set
Alright then if that’s the case it makes sense, thank you
it's not a 'contradiction'
it's just, the set contains elements that satisfy a condition but there aren't any that satisfy the condition
The way I read this is “you can write a set in C as long as it satisfies these conditions: (the conditions in the interval notation)”
But clearly that’s not the case
It does not need to satisfy a less than b even though the interval notation says that
So I see that if it doesn’t satisfy those conditions, it’s still a legit set in C, it just equals the empty set
Makes sense I thinkkkk
yep
Thank you

.close
Closed by @round forge
Use .reopen if this was a mistake.
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 really not sure what to do with this one
I see there is a quadratic in the denominator so I bet I need to set the discriminant of that > 0 at some point to find where there are 2 values of y or something
But yeah I have no idea what the first step is
Why do we set it equal to p? sry
you will get something like $x_{12}=A\pm \sqrt{B}$
NulledOutChicken
Because this is how you find intersections. f intersects g at a <=> f(a)=g(a)
Closed by @warped topaz
Use .reopen if this was a mistake.
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
where exactly are you unsure?
and see if you get a ratio of 1/2
the last two
oh
try to look up how to divide fractions by fractions
you should be able to solve that on your own
If you divide pizza into 3 pieces, then you take 1 of the pieces and divide it into 4 pieces and take 1, how large will it be (what fraction of the og pizza)
np
Alright, if that's all you can close this channel with .close
do i just type close or
Closed by @modern sedge
Use .reopen if this was a mistake.
(it's already closed now)
green privilege
Huh it didn't work earlier?
Nah i was a helper once , I mean then it wasn't available
It's quite an old feature, maybe you were helpful a really long time ago
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 isnt a rule btw, at least afaik
how do you solve this?
na
actually
yeah
you dont have to
just do some calculation you will end up with the prime factor decompose of it anyway
@compact osprey Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
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.
Decide in natural numbers: x^3 - 3 = 2y^2
I know that x=5 mod 6
so how much do you know about elliptic curves?
nothing
what level of math are you studying?
Olympiad
Can it be helpfull if we write it ?
(x-1)(x^{2}+x +1) = 2(y-1)(y+1)
x-1 divides 2(y-1)(y+1)
Why?
From equation
Sorry, got it
rhs is 2(y^2 + 1) not 2(y - 1)(y + 1)
Maybe we can use it?
we can solve for x^3, x^3 = 2y^2 + 3, now, assuming x = 5 mod 6, and working under mod 6, the cube actually is transparent. That is a^3 = a mod 6. So we have 5 = 2y^2 + 3, or y^2 = 1 mod 6. The y^2 becomes 1 whenever y = 1 or 5 mod 6. So now you have a limitation mod 6 on y.
but I don't feel like this is significantly closer to a solution 😦
@sick lion Has your question been resolved?
when substituting x=3k, you see that y is divisible by 3 and by substituting y=3l and dividing by 3 one gets mod 3 that 1=0
Yea
We can view this in Gaussian numbers Z[i] but I think its overcomplicating
I think there's a solution without them
@sick lion Has your question been resolved?
.close
Closed by @sick lion
Use .reopen if this was a mistake.
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.
Not sure how to do this at all
I thought it was looking for points of intersection
But I don’t think it is after looking at answer
Answer is F
Why do you not think it is [points of intersction]? And by "points of intersection", assumedly you mean where y = tan(x) intersects y = 100x?
@heavy vale Has your question been resolved?
Yeah plot 100x, plot tanx and see where they meet
Closed due to timeout
Use .reopen if this was a mistake.
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.
Please don't occupy multiple help channels.
I need help
alr lemme see
.close
Closed by @limpid turret
Use .reopen if this was a mistake.
Stay in one channel please
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 find the values?
One of them is correct, but I don't know which one it is
You found a value for which h(x) = 4, not -4.
There is actually a unique answer to h(x) = -4
@slow island Has your question been resolved?
I figured it out
Closed by @slow island
Use .reopen if this was a mistake.
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 need to use complex numbers for this i think cuz it is on the complex number section
I know cis^n (theta) = cis (ntheta)
But idk how can i use that
do you know the complex definition of cosine
Like if u have z = a + bi the cos is a over sqrt (a^2 + b^2)?
no
So no
Do you know e^iθ
Yeah
what's e^iθ + e^-iθ
e^i(-θ) ?
Is it?
No
Oh
Just the right term
Yeah i still do not know 😦
what's e^iθ
expand
Cos + isin
Oh yeah i could do that
Hold on
2 cos (theta)
Ohhhhhhhhhhhhhhhhhhh
Interestinggggggggggggggggggggggg
Thanks
Np
Wait can cis (a) = 0?
Hmmmmmm
If not, x = cis (a)
And then done cuz u can just do 0 = 0 for every n 🙂
Uhm i do not think cis (a) can be equal to 0
Cuz we would have cos a = i sin (-a) and idk how to solve that
.close
Closed by @fervent lichen
Use .reopen if this was a mistake.
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.
does anyone know how we got from the second to last step to last step
Please don't occupy multiple help channels.
Closed by @silent goblet
Use .reopen if this was a mistake.
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 you do this question
start by finding how much money he earned in his second and third years, in terms of d
How would you do that
use the information given at the top of the page
I got 3x+300= d
what is x
we are given that d is the amount of money he earned in the first year
Isnt that 3d+V
3d + V is the average amount of money, d is the amount of money raised in the first year
Oh mb I can’t read
So second year would be 6d+2v
And third year would be 18d+6v+300
Then I average and solve
in the second year he raised twice as much money as the first year. in the first year the money he raised is d
V=100 then right
Yeah that was the answer thank you
.close
Closed by @fossil basalt
Use .reopen if this was a mistake.
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 is this incorrect? They share the same exact thing meaning more than one point
So how is this wrong lmao
A and B are the same thing
Is it because it says ( angles ) and not ( angle )
@neat rune Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
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.
cosine is a periodic function
if we shrink the period (which is what 3x does)
it oscillates faster
therefore we'll end up with more solutions within a certain domain
than if the period wasn't shrunk
so its 360/3
so the period is 120
but shouldnt it be 60
because ur not really finidng the period, only the number of times it crosses the line at -1/2
right
so how does that yield 160 200
right within 0<x<=360
ok lemme pullup desmos
Oh wait
sorry i assumed that the intercepts were equally distanced but i forgot we not talking about the x axis 💀
So ur supppoed to tkae the two solutions i originally found
and add 120 to them
?
your range is 0 <= x < 360, but you're solving for cos(3x), so you can extend your range to 0 <= 3x <= 1080
so i shouldve left it all at 3x
and then found the solutions by adding the period
and then divide all the soltuions by 3
adding 360 yes
then divide all by 3
so just adding 120 in the end
is the extension of the range nessecary for working points?
?
like think about it
i already found X
not 3x, x
so then i can just add the period of this wave to my solutions
no need for this funny buissness right
i suppose you can but i always do this
Closed by @brisk spindle
Use .reopen if this was a mistake.
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.
number 12 plz
Is that we need to simplify it?
just multiply it dawg
Given: (a+bi)(c+di) = ac + bci + adi -bd
@void sable Has your question been resolved?
i got 14-rad 70 i plus rad 140i plus 5 rad 2
i just dont know what to do next
@drifting seal
@alpine sable
group the imaginary part and the real part
and that should be it
Ye
ok i got it right then
@void sable Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
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 find the domain and range, im confused with the gaps, please help thank you.
It takes the value where the closed dot is made
how can i open a help channel?
And dosent take the value for the open dot
Since it's a piecewise function
for the range?
Yea for the range look for the values the function can take
For the first one it will be -1 to 3
For the second it will be -infinity to infinity
For the third one you should make brakets since the function takes all values between 2 And 4
so for number 2 the range and the domain will be the same answer?
No the domain is -3 to infinity
But range is -1 to 3
Ohh wait yes for the number two range and domain are same
Sorry i thought u were Reffering to number 1
Nvm I'm just high 
HELP
u helping me tho so I appreciate it 😭
the third one what is the domain would it be -5 to 5?
Can u help me
bro I need help as well
!occupied
Someone else is already using this help channel. If you need help with a question, please open your own help channel/thread (see #❓how-to-get-help for instructions).
@rustic minnow Has your question been resolved?
Nope look closely the u can substitute x values from -5 to 1 but between 1-2 function is not defined so the domain should be [-5, 1] u (2, 5]
Ok
Not to be rude sorry but do u know what domain and range are?
Again I'm just asking not taunting you

If not I can help u understand
kinda, like the domain are looking at the x values and the range the y values?
thank u sm 🙏🏽🙏🏽
again sorry but for number 4 the domain would be -3 to 3? n the range would be -1, 1, and 3 or am I just lost
Yes values for which the function is defined
Yes 
You're welcome 
I've answered u in the other help channel

IT TIMED OUT GRRRR
wait why is it not -20? i thought it was bc it has the lowest point
How come -20 is the lowest point
Huh? The lowest value y is taking here is less than 5
oh!
Where what I can see is that graph is only defined for positive
I thought since it didn’t have a point I didn’t think it was the answer
bruh
It doesn't matter wheather it's a point or not if the function is defined there it can be the maxima Or minima
Np 
It's good to be slow
Why minus?
Is the value that y is taking -ve
omg I got confused it would be 4
Yes perfect 
and the domain wouldn’t be 39, to infinity??
Can x = 1 here
Look is the function defined for all x other than for x = 0 , 16 , 61
So what all values can x exactly take
it would be all real no exept these ones
how would I put it as an answer
(0, 16) u(16, 61) u(61, infinity)
sorry for the late response
thank u so much for helping me along the way 🙏🏽🙏🏽
bless ur soul
saved a life right here
goodnight n thank u again!!
It's morning here but ok gn to u
Your welcome

@rustic minnow Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
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 I'm stuck here.
what I tried first is find the area using pi r^2 where I got 78.5 using that 5in as r then idk what to do next.
to find the area of the shaded region, compute the area of the square minus the the area of the circular sectors
is the area of the square the ones with r?
while the sectors are abcd?
cuz if so then the sectors are equal to each other?
oh wait brain dead sorry
I followed this site to solve but I can't understand it either
while for the sectors I used 78.5in where I'm not sure myself if its the one to use
or should I consider the radius to get the sector?
@spice venture Has your question been resolved?
.close
Closed by @spice venture
Use .reopen if this was a mistake.
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.
None of this is in my course yet, but I was wondering what other ways there are to integrate expressions like 1/(1+x^5) and my first guess was to write it in the form of it’s Taylor series
What are the conditions that a function/expression must follow to have a Taylor expansion (in layman terms)
well a function that can be represented by a taylor series is called an "analytic function": https://en.wikipedia.org/wiki/Analytic_function
In mathematics, an analytic function is a function that is locally given by a convergent power series. There exist both real analytic functions and complex analytic functions. Functions of each type are infinitely differentiable, but complex analytic functions exhibit properties that do not generally hold for real analytic functions.
A function...
one thing that's worth noting is that taylor series will only converge to their function inside a particular interval. for some functions that interval is the entire real number line.
I see I see
but for 1/(1 + x^5) we would expect that to have a radius of convergence of 1
so if we expanded at x = 0, we would expect the series (and hence its integral) only to converge in (-1, 1)
we can expand it about any point
but the radius of convergence is 1, so the interval of convergence would be (a-1, a+1)
hmmm
So if I wanted to write the original function in terms of its Taylor expansion entirely, so that it covers all its domain and range , would I have to make a piece wise function?
sorry for pinging >.<

if you integrate the taylor series and you're able to simplify the resulting series back into an expression which is defined everywhere then that will be the integral
yesyes that was my goal originally
that's probably not easy
you might have an easier time doing partial fractions over C
apologies, this was incorrect. the radius of convergence does change based on the point (i am up too late, sorry)
the radius of convergence is kind of irrelevant here though because whatever power series you get will define a unique analytic extension
I see I see
still out of interest, is there a meaningful way to attempt this
well you could try expanding out the geometric series
it looks like you might have to some kind of roots of unity filter though
but that would only apply for |x|<1
there's a unique analytic continuation, so it doesn't matter
I dont really know what an analytic continuation is
like if you have a power series that's defined on some ball, theres a unique analytic function that extends it on some maximal subset of C
so if you can work out the answer for |x|<1, then you have the answer everywhere
woaaaa this is genuinely so convenient
I wonder how the proof of it goes tho that’s beyond my scope
it's called the identity theorem
thanks a lot, I’ll check that out
one more thing
the geometric series I got for |x|<1 was 1 -x^5 +x^10 -x^15+…
how would that look like after its analytic continuation?
yep
so that's the analytic continuation
even if the power series is only defined for |x|<1
but if you had some random power series that didn't come from an expression that you expanded
you could try unexpand it
like 1 + 2x + 3x^2 + 4x^3 + ... is the derivative of 1 + x + x^2 + x^3 + ... for example
so you could "unexpand" it by simplifying it to 1/(1 - x)^2
that extends the power series analytically to all of C except at 1
oooh
in gp cases it’s like the reverse process of finding the sum
alright, got it, thanks a lot c:

Closed by @mild fractal
Use .reopen if this was a mistake.
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 have to find values for rho, t and theta. This is a swap of coordinates I have to use to find a parametrization of the curve of intersection between an iperboloid and a cylinder that are $9y^2-4z^2=9$ and $9x^2+4z^2=36$
x_Shadow_x
I've already found rho and t that are easy, but I'm stuck to find theta
it should have a range of [-pi, pi]
but how
@autumn acorn Has your question been resolved?
@autumn acorn Has your question been resolved?
<@&286206848099549185>
I think it goes well every theta since it always satisfy both equations. but is it a problem if it goes from 0 to 2pi instead of -pi to pi as solutions?
@autumn acorn Has your question been resolved?
@autumn acorn Has your question been resolved?
@autumn acorn Has your question been resolved?
yup
then I tried to draw it on geogebra
so
and setting theta with a range of -pi to pi or 0 to 2pi nothing changes
so I don't think it was a problem to consider a range of [0, 2pi] instead of that one of solutions
@autumn acorn Has your question been resolved?
Closed by @autumn acorn
Use .reopen if this was a mistake.
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 question is find the value of p and q
what does it mean mathematically when the golf ball is on the ground
I think its saying like the ball was static 3 meters to the left from point A. Then it was hit and then traveled until 10m from the point it was static which was 3m away from point A
if you get what im saying
quadratics for anyone wondering
@signal shale Has your question been resolved?
Closed by @signal shale
Use .reopen if this was a mistake.
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 someone just walk me through how we solve this by "extending" with x-1?
I got the right answer using L'Hopitals, but would like to know how the alternative approach works
well i'm confused about how they wrote the answer
but we're essentially doing sin(x-1)/x^3-1 * (x-1)/(x-1) yeah?
and then we can move then sin(x-1) over to the right one and that one to the left?
i mean yeah that could work too
and we get sin(x-1)/x-1 * x-1/x^3-1
mhm
and now we can suddenly split the limits?
and that's okay when we have multiplication between the terms? or always?
it’s okay as long as both limits exist
interesting
if they don’t then splitting up wouldn’t give you the correct answer
well yeah then we get 1 * (x-1)/(x^3-1)
and then how would you easily factor out x^3-1?
using the difference of cubes
don't think i've heard of that one before
y0shi
haha
but yeah if you use that
the x-1 would cancel out
and it’s just substitution
yep
mhm exactly
cheers mate, you're a legend
yw!
Closed by @eager iron
Use .reopen if this was a mistake.
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
plug x
how
In place of x
6x6 is 36
Write -6
is now -36
-6×-6 = 36
if x=2 what's 3x
-1×-1 = 1
,calc 36-48+7
Result:
-5
@gilded marten Has your question been resolved?
like when i simplify everything
and i think everything is correct it becomes wrongh
Closed due to timeout
Use .reopen if this was a mistake.
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.
hello
I need help with this question:
investigate for which values of b does the equation lack any real answers
sqroot(2x + 1) = x + b
I plugged it into geogebra and slid the thing
but I'm wondering if this can be solved algebraically
Is the answer 1 and -5/3?
let me check
If so then you could square both sides and get a quadratic in x
Then the discriminant (a quadratic in b) would need to be negative for no real solutions to exist
b is bigger than 1
I meant to write b ε R - {-5/3, 1}
But my answer is still incomplete
how would I use the quadratic formula
We know that no real solutions of x exist
So the discriminate for this quadratic must be negative
You need to calculate the discriminant
yeah but how would the quadratic look like
I’m used to only one sole variable when I use it
x² + 2x(b - 1) + (b² - 1) = 0
The coefficient of x is 2(b - 1)
And the "constant" term is b² - 1
The correct name for that term would be the term independent of x but people are used to calling it the constant term
then you can substitute x1 or x2 in x1x2. does this help?
sorry what is x1 and x2?
roots of quadratic equation
@crimson crag Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
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 can’t figure out what I’m doing wrong:
Suppose that a wind is blowing in the direction S45°E at a speed of 40 km/h. A pilot is steering a plane in the direction N60°E at an airspeed (speed in still air) of 300 km/h. The true course, or track, of the plane is the direction of the resultant of the velocity vectors of the plane and the wind. The ground speed of the plane is the magnitude of the resultant. Find the true course and the ground speed of the plane. (Round your answers to one decimal place.)
I think your planes direction is wrong? N60E means 60 deg east of North, so the angle should be the other way
Otherwise the calculations seem right
if it was the other way, what would the angle be when calculating it? like 300cos(angle) and 300sin(angle)?
I mean you have 60 deg wrt x axis in your figure
but the source I linked seems to say it should be 60 deg wrt y axis in 1st Quadrant
yeah I get that
or 30 deg wrt x axis
@sturdy spear Has your question been resolved?
Closed by @sturdy spear
Use .reopen if this was a mistake.
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’ve been trying to look everywhere but I haven’t found a solution…
I’ve been stuck but I’m trying to convert 53/22 into a mixed number percent ** not** a mixed number into a percent.
convert the fraction to a percent, then convert the whole number next to it into a percent, then add them together
thanks for clarifying, "mixed number percent" is not a real math term
did it tell you the percent was incorrect?
It’s because it can’t figure out the fraction part. I have 240%
have you tried 241%
But idk how to get the fraction
Here an example
I did. The software won’t take it though
you mean like $\frac{10}{7}$ becomes $1\frac{3}{7}$?
What?
for this, you multiply 53/22 by 100, simplify it into a mixed fraction, then put a % sign after it
didnt realize that was called a mixed number percent
Bacter10Fr4g
Thank you!
np
@stoic barn Has your question been resolved?
Closed by @stoic barn
Use .reopen if this was a mistake.
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 i need help in quadratic formula, sometimes when i’m solving for the root, the 4ac is always bigger than b² is it normal or i’m just dumb because i always ends up getting negative, what i do is i’ll get the value of b² first then i do -4(a)(c) then b² - 4ac
always?
It’s fine if you get that, just check if you’re missing any negatives for a or c
Not always
my substitution are correct, if it’s fine what would be the next step if the root is negative?
the solution will be imaginary
If 4ac >b² then the roots are imaginary
the root(-1) becomes i
Because in the quadratic formula you get something like ( -b+√(-n))/2a
Where n is a number
how to find the value of x if the roots are imaginary? my teacher didn’t gave an example of it😭
Do √(-n)=√(-1)$\cdot$√n
faiyrose
Thanks 👍🏿
lastly where do i get the number of the n?
$\sqrt{-1}$=i
i’m failing 9th grade 😭
;-;
David
No you won't
ah i see, it’ll be always imaginary if root is negative
lastly where do i get the number of the n?
|b²-4ac|
This
W
If b²-4ac is -ve then you have the case √-n
Where n is the absolute value of b²-4ac
i’ll just turn it to positive if 4ac>b² because of the ||?
what do you call that thing again
Absolute value of
Closed by @acoustic needle
Use .reopen if this was a mistake.
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 am looking for exercise book (with solutions) recommendations for introductory real analysis please 🙂
try searching 'real analysis' in #book-recommendations
.close
Closed by @atomic steppe
Use .reopen if this was a mistake.
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.
Hello
Yes papa
dtheta goes from -pi/2 to pi/2 instead of from 0 to pi
after you integrate dr, you have to integrate cos(theta)^3
to do that, split into cos(theta)^2 cos(theta) then rewrite as (1 - sin(theta)^2) cos(theta)
this lets you use u-sub u = sin(theta)
its alright i know how to continue
but i dont know why my professor choose 0 to theta
when it is from -pi/2 to pi/2 imo
you should take a bigger screenshot
I have a feeling the professor just misremembered the bounds for r = cos(theta) to be from 0 to pi
it should just be a typo
@alpine sable Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
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.
why is the code not working
is that the command for the dot product?
wait, did you run the other cell before? it says In[1]
oh wait i forgot to run the top command
i ran it before and then quit and now i came back
thats why
anyway do u know how to do the problem
.close
Closed by @vapid steppe
Use .reopen if this was a mistake.
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.
would it not be more straightforward to use impulse-momentum theorem?
F * delta(t) = delta(mv)
oh
yeah i just realized it's equivalent
F = ma = m dv/dt = d/dt (mv), so Fdt = d(mv)
both approaches give you 0.07
Closed by @cloud stump
Use .reopen if this was a mistake.
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 get an equation for this along with drawing the line of best fit
algebra 2^
@jaunty bloom Has your question been resolved?
@jaunty bloom Has your question been resolved?
@jaunty bloom Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
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 a primitive root exist under modulo m if m is not a prime?
What's the exact condition, and is it proved?
In modular arithmetic, a number g is a primitive root modulo n if every number a coprime to n is congruent to a power of g modulo n. That is, g is a primitive root modulo n if for every integer a coprime to n, there is some integer k for which gk ≡ a (mod n). Such a value k is called the index or discrete logarithm of a to the base g modulo n. S...
it is stated there
It's very useful, ty for the quick resp. too.
So 9 has it even though it's not a prime because it's p^k with odd prime p and k > 0.
yep
Closed by @hoary herald
Use .reopen if this was a mistake.

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 does it mean to find the derivative of a function with respect to anything other than dx
Like $\frac{d\sin{x^2}}{dx^2}$
PianoDolphin
I always write derivatives with the little dash up top and haven't reallly used this notation
It means to write find the dervative of sinx and replace x by the inside function ik that
But what is it asking?
you can write chain rule definition:
$$\frac{df(x)}{dg(x)} = \frac{df(x)}{dx} \frac{dx}{dg(x)}$$
rafilou2003
I know the chain rule
I write it using the dash defination
But like what does this even mean d(sinx)/dx^2
it means "how much does sin(x) instantly change when x^2 instantly changes"
A dx^2 in the denominator usually implies a second derivative.
But it is missing a corresponding d^2 in the numerator.
I think that happens in the numerator
Unless d(sin(x))^2 was implied.
did you mean $\frac{d^2\sin{x}}{dx^2}$?
rafilou2003
no no
So we are asking, how much times does this function change as we change the value of x^2, but the the question is how are we changing the value of x^2
?
by changing x right, like inputting 2.000001 instead of 2
well you can link change in x^2 back to change in x
with the RATE OF CHANGE of x^2
dx^2/dx
yes but then my confusion is that how is this any different than just saying df(g(x))/dx
isn't this asking the same thing, how does f(g(x)) change instantly with a very small change in x
or rather how many times is that change bigger than the small change in x
? you're not looking at how f(g(x)) changes with a change in x
first of all you're looking at f(x)
and then you're looking at how it changes with a change in g(x)
so if you wanna see it like this
pardon me if I'm wrong but in the case of x^2 vs. x imagine taking x = 0.0000001 and inputting it through the function and in that case you can see that the increase in y in that case will be different for x^2 and x
you could write f(x) as f(g^-1(g(x))
and so f(g^-1(g(x)) with a change in g(x) makes more sense
I said $\frac{df(g(x))}{dx}$
PianoDolphin
I agree that's what you said
and I said that's not what we're looking at
we're not looking at change of f(g(x))
we're looking at change of f(x), with respect to g(x)
so more like
But how is this any different from df(g(x))/dg(x)
Here we are asking how much does f(g(x)) change when we change g(x)
here we are asking how much does f(g(x)) change when we change x
but the only way to change g(x) is by chaning x
oh wait
but
I got it
ahhhhh
well that was a confusing couple moments ll
lol*
that is what I get for always using f` notation
for derivative
yeah, to explain a bit more
this is f'(g(x))
yeah that I know
this is [f(g(x))]'
yes that I know too