Channel closed
Closed by @vast furnace
Use .reopen if this was a mistake.
1 messages · Page 176 of 1
Closed by @vast furnace
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 am i supposed to solve this exercise with only BASICS of integrals (No substitution or whatever but only reverse formulas and first 2 linear proprieties):
Please don't occupy multiple help channels.
Write sin(x) in terms of tan(x/2)
Book's result: (sinx - 1)/(cosx) + c
@thick hedge
That's substitution
ah, right
yes?
What is it?
sin(x) = 2tan(x/2)/(1+tan(x/2))
Hmm, idk if i am supposed to do that
that's what i tough but my mind's calculus went to an unresolvable solution
let me try again
omg
i solved it but in a strage way
i mean, i don't think that i am supposed to do the last operation:
Writing that integral of sinx/cos^2(x) is equal to -1/cosx
i mean, i shouldn't solve integrals by thinking " is that expression the derivate of 1/f(x)?"
you did it right
However that's a clever way to solve it, i should memorize that formula
that's my book of 2 years ago of goniometry
this is what normal people do
yeah
Also my teacher said that inside integrals i cannot multiply and divide by x (and i dind't understandy why) or maybe i didn't understand what she meant.
Can i do it?
that won't help in this case
but can i do it?
yes
Ok, but if i do it then x must be != from 0.
When i do integrals, do i have to mind about Domain?
but of all the integral questions i have come across, i have never used the above method
I mean, when i get the main function, what happens to the Domain of the function i have to integrate?
ok
i didn't ge tyou
I have to integrate that function f(x) which integral is F(x), yeah?
Initially, f(x) has it's domain (such as x != 0), but when i integrate f(x) to obtain F(x) (which may not have x to the denominator and so x can be 0), what happens to the domain of f(x)?
.close
Closed by @leaden yarrow
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 prove that the recursively defined sequence $(an)$ which is is defined as $a_1 \coloneq 2$ and $ a{n+1}\coloneq \sqrt{1+a_n}$ for $n\leq 1$
converges, and I need to find it's limit.
Lukas
Channel closed due to the original message being deleted.
If you did not intend to do this, please open a new help channel,
as this action is irreversible, and this channel may abruptly lock.
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 do you mean by "x != 0"
.close
Closed by @dry zodiac
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 I drew a circle and chord and constructed triangle PAB
If we take area of triangle it's 1/2* PA PB sin P
So PA PB = 2* area / sin P
As P is constant
We need to maximise area
Which is maximise height of traingle
How to select P in such a way?
<@&286206848099549185> sorry for ping

<@&286206848099549185> please ?
Yes?
And b too it's all same question
@indigo 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.
Where is the 6 coming from? since HA is at y=0?
im not sure how this 6 correlates to the asymptote
could it be that they're multiplying the intercepts?
but that wouldnt make sense since 2*-3 = -6
Simply plug in the value of x where the function is nonzero
When you come up with your initial function, there is a k constant that it is multiplied by.
You then use a known value to determine k.
how is 6 a known value though?
Substitute either points into the equation above and solve for k.
Hmm, (2,0) would not be a good choice since it is an x-intercept.
edit : intercept to x-intercept
(0,-3) is also an intercept
The x-intercept will not be affected by a vertical stretch.
However, the y-intercept will be affected by a vertical stretch.
👍
Closed by @analog ridge
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.
Here's just the full problem for context, my question is more specific
We are able to get to an 'ODE" $$ \pdv[2]{\tilde \phi }{ z} = s^2 \tilde \phi$$
jan Niku
now I lost a few points on the old final because i didnt consider all the cases but im curious how exactly this works now
say we take s=0 does that mean that we get the solution $\tilde \phi = A(s,t)z + B(s,t)$?
jan Niku
and then how do we reject this solution given its not present in the answer
solution mentions this method but ignores s=0 as well
@plush egret Has your question been resolved?
@plush egret Has your question been resolved?
$\pdv[2]{\tilde \phi}{z} = s^2 \tilde \phi$
jan Niku
@plush egret Has your question been resolved?
Which part of the question it is?
So the fi = to integral of something is the same fi you find in first part by solving differential equation?
sorry, i didnt realize you'd replied
the question is about the s=0 case
like, it is possible for s=0
you end up with $\pdv[2] z \tilde \phi(0,z,t) = 0$
jan Niku
jan Niku
i mean theres more but agreed up to here?
Yeah but is this part 1 or part 2?
So you want to get rid of dfi/dz
we just want to pick up every component of the solution which satisfies the underlying model given by the BC and IC
this is part ... there are no parts
this is the part "show that"
You mean you solve differential equations for all variables of fi?
have you solved a pde via fourier methods before?
No.......
hmm
it creates an 'ordinary' differential equation
rather its a partial differential equation but only one variable is present
$\pdv[2]{\tilde \phi}{z} = s^2 \tilde \phi$
jan Niku
Now you need to solve this
so s can be anything
then theres 2 cases here
s^2 can be positive or 0
each contributes a solution, m aybe
I'm curious about the case where s=0
this requires solving $\pdv[2] z \tilde \phi = 0$ and applying the boundary conditions
jan Niku
How is s defined here?
its a transform variable
have you done integral transforms before?
its just a fourier variable weve shifted one of the variables to another domain
Is there a link for this paper with solutions or any other context ?
Alright I will try to brute force it so it probably take whatever amount of it.
Have you tried any calculus subredidts?
Maybe studentroom forum
For me onky way to get sensible answer is to trace whole context which will take a lot of time.
So yeah, that's kinda how it is the harder the question the less possible that you will get answer on it
That's why I am saying that someone good at calculus might give you an answer straight away. But I need to rely on context
its just that we transform to another function
So that's kinda the problem by itself how to get answer evn on this specific question
the solution is some say $\phi(x,z,t)$
jan Niku
so we instead solve a pde for some transformed function
$\tilde \phi (s,z,t) \triangleq \int _\mathbb R \phi (x,z,t) e^{isx} \dd x$
jan Niku
we transform each equation and boundary condition the same way
for example youll find that $\int _{\mathbb R} \nabla^2 \phi e^{isx} \dd x = \pdv[2] z \tilde\phi - s^2 \tilde\phi$
jan Niku
I mean if s is constant you can pick any value and it should be valid solution.
But again I just had question with dummy variable in differential equation and question had no specific context so I could have just used special case for my differential equation like n=1
Well I ment that n was a free variable so you can pick any value for show part of the question. So like to solve for particular value of n you pick
so we have to check each possible value of s to see if we get a solution that we need to accumulate
s is not free
its no more free than x is in y'(x) = y(x)
Alright so what can you do with solutions when s=0
Are they useful for you in any way?
If yes
Then is it contradict with any other solutions
If no
Then is it complete the answer.
?
no, its like this
you de transform
$\int _{\mathbb R} \tilde\phi e^{-isx} \dd s = \phi (x,s,t)$
jan Niku
something like this
you see how s sweeps from -inf to inf
so if for some value of s there is a solution, we accumulate it as we un-transform
@torn jolt this is all big picture which is not really required for my specific issue
.
.
jan Niku
you get $\phi (0, z, t ) = A(t) z + B(t)$
jan Niku
sorry, this should be tilde
but lets drop it for a second
you aply the boundary condition $\pdv \phi = 0$ on $z=-h$
jan Niku
then $A(t) \equiv 0$
jan Niku
so $\phi (0,z,t) = B(t)$
jan Niku
yea?
Alright
So for particular value of s there is particular solution that is not listed in markscheme as a possible solution and you want to reject it?
idk how much more to explain
Alright what will happen if s=1?
i'm just explaining my solution in this specific context
Yeah I know.
the solutions are not different here
we can consider s != 0 collectively
since they vary continuously with s
particular and general idk what you mean
Their method Makes more or less sense
Since - inf +inf not really defined so they combine it in such way to suit argument
I don't think setting s=0 contradict with their solutions.
<@&286206848099549185>
@plush egret Has your question been resolved?
Closed by @plush egret
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.
someone teach me
approach with rational root theorem
Closed by @hidden delta
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 to solve this using comparison test
@edgy osprey Has your question been resolved?
oh sorrry
find if the limit converges or diverges
its a limit n to inifinity
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.
if its continuous then we're good by clairauts
or young's, whatever u call it
f_xy = f_yx
Hahaha, i’ll search that up
👍
i learned it as young's, but after coming here, i learned it was also called clairaut's lol
and apparently theres another name too
anyways, its the theorem of equality of 2nd mixed partials
yep
Ahhh, so we need to check if its continuous then for this to hold.
What if it isn’t?
Then we do xy and yx manually and multiply them?
I didn't even know it had name lol
probably something like that. but just lacking continuity doesnt necessarily imply that f_xy != f_yx. it just may not be true, but we don't know for certain unless we check. young's just guarantees it when we do have continuity. without continuity, we may or may not have equality of 2nd mixed partials
u can quote me on the second sentence, but im not 100% on "Then we do xy and yx manually and multiply them" so
but it makes sense so

np
.close
Closed by @distant swan
Use .reopen if this was a mistake.
Another one, finding max and min
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 to find max min and saddle points of this one?
@distant swan 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 solve this? i'm not really sure where to start
Do you know what the maclaurin series is?
i know that the maclaurin series for sin of x is x - x^3/3! + x^5/5! etc
Good
So with the given properties the first two terms are both zero
The first non Zero term would be
0.5×f''(0)×x^2
So you wanna think what the derivative of f'(x)=sin(x)^2 is
Sorry for all the typing but I'm on my phone
no worries!! thanks for all ur help in the first place
2xcos(x^2)
woulkdn't that just result in 0?
if i were to plug in 0
I don't think so
2(0)cos^(0^2) = 0
Oh true I didn't see the x, I should go to sleep 😴
haha no worries
Okay then we have to calculate the next one
but i think it would just keep giving us 0 forever
if we keep taking the deriv
cause you're always multiplying by 0
ohh oops i forgot about that
alr let me try and take the product rule
2cos(x^2) + (4x^2)cos(x^2)
so it would be 2?
Looks.good
Yeah but
The entire term would be
1/6 × 2 × x^3 then
So then we have found the first non-zero term of the solution! That corresponds with answer 3 and 4, so we have to go one further
ohh okay i see, but why'd you multiply by 1/6?
Because of the maclaurin series
SORRY i keep thinking thats the second derivative omg
okok got it so 2(x)^3/3!
which is x^3/3
Yeah
makes sense
Judging from the solutions given, the next term would be at x^7 which means you need a few more derivates first
ah okay
would there be an easier way to do this?
seeing as taking the deriv each time takes quite a while
yeahh unfortunately this is from the ap calc bc exam on the non-calc portion so i'd have to do it manually
ohh okay, so there's no shortcuts or anything?
not that i am aware of , sorry
no worries!! thanks for your help, vien and zue :))
You're very welcome
.close
Closed by @fast agate
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 would need some help with a double integral, please
I've made the first part of an exercise but then I need to deduct something from my result and I don't quite see how it should be done... My first guess is to use the Fubini theorem, but my attempts lead to nowhere
You'll find my work below 👇 (I'm sorry if the redaction isn't accurate, it's the first time I do math in english)
Heres an idea
It might be kinda reaching considering we already know what the bottom integral should be
But
Integrating e^(-x²+y²) with respect to dx and dy
Is the same as integrating e^-x² dx and integrating e^-y² dy
Since the bounds are same, and the function is the same, it's just the square root of π/a
Is that how I should write it ?
What exactly is the question
The math looks good but I’m not sure if you’ve answered the question (cos you haven’t posted what the question you’re solving is)
Calculate the double integral... where a>0. Deduce the value of...from it
Is that in general that if the x part and the y part of
int (f(x,y) dxdy) are the same, then it's just (int (f(x) dx))^2 ?
@brisk grotto Has your question been resolved?
Closed by @brisk grotto
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.
When manufacturing aluminum funnels (cones without the base), designers always aim for least materials cost, that is least surface area of the cone. If we want to manufacture a funnel with a volume of $2dm^3$, what should be the minimum value of its surface area?
dm being decimetre?
not sure how to approach this, i have pi*r^2*h=6, but not sure how to find least surface area from it without at least the base radius or height
volume of cone = pi x r^2 x h/3 = 2
cube? you mean cone
you want to minimize its csa = pi x r x l
yeah mb
yeah thats the whole point
sub in here
and differentiate to find the minima
id have a 5 degrees
pretty ugly
but let me try
doesnt seem correct, the min value doesnt exist
r^2 + 36/(pi^2 x r^4) needs to under a sqrt
oh right, my bad
still doesnt give a minimum value
oh wait
solved, its 6,65dm^2
.close
Closed by @craggy tapir
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.
Channel closed due to the original message being deleted.
If you did not intend to do this, please open a new help channel,
as this action is irreversible, and this channel may abruptly lock.
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 come median not 5? when i draw a line at 50 and line it up with the graph it looks more like 5
what's the actual median
it says 3.5
tbh i'm pretty sure the scale is just broken
Closed by @twin wolf
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's the easiest way to solve 1200/0.63 without a calculator? Is this ability reasonable to expect on an Algebra I level? I asked chatgpt and it fully told me to use a calculator
A decimal
being able to calculate this isnt useful in algebra at all
like its not what algebra is about
the concept of long division is actually useful though
i mean it is
due to relevance with euclidean division and polynomial division
just dont expect to see things like: calculate 1200/0.63
you could first multiply numerator and denominator by 100 to rid yourself of that initial decimal
then divide numerator and denominator by 3
I've been brushing up on my long division for like a week and it got me to solve the actual problem another way (and it feels so GOOOOOOOOD) but if I should know how to do it this way too I wanna be able to do it
how do you say 1200/0.63?
one thousand two hundred point sixty thirdths?
resulting in 40000/21
which is somewhat less intimidating to divide
I'd gotten this far but floundered here
then approach it like you would any other long division problem
Huh
Yeah that worked lol
Idk why I felt like I couldn't do that
Thanks for clarifying my thoughts after I've been so math-forest-addled
.close
Closed by @covert wraith
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 someone help me understand what three equations can be formed with this information.
what they wrote down has to be true for n=1, n=2, n=3, n=4, ... and so on
and...
how does the equation look for n=1
oh you need context
alright
ah i see
so justplug in different values
to form three equations
got it
tysm
.close
Closed by @forest jackal
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 dont know how my teacher got from k(x) to k'(x). I know that the this function has to be treated as two and I understand how to go from 250x to 250 and e^(-o,5x) to -0,5e^(-0,5x), however I am struggling to understand why I can exclude the twenty. Is it not linked to the e part of the function?
But isn't it linked to the e and has to stay with it in the first part like : 250e^(-0,5x) +20 because I only derive the 250x?
It isn't linked to the e no
It's just added at the end of the function
Different terms
oh okay. So I can always leave it out completely like when I do linear derivatives during linked functions?
Well if it's separated by a plus or minus it's a separate term
So it's not linked to the e here and is its own term
The derivative of a constant is 0
If you have a sum of two things, you can differentiate them separately, and a constant always differentiates to 0
So for example the derivative of x+x would be 1+1
The derivative of x+1 would be 1+0
If it helps you to think about it, 20 is basically just $20x^0$
DJJ
I understand that numbers without an x always turn to 0, I was just a little confused because of the links and different rules that were introduced with them. But I get why it is still seen as a single term and can thus be left out in derivitating. Thanks for the help :)
.close
Closed by @delicate oasis
Use .reopen if this was a mistake.
np ^^
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 on integral
Tried substituting cos x here but it solves nothing at all
Looking for a way to solve this with high school integration methods
no elementary antiderivative
not sure where you saw this, but ive seen this integral with limits of 0 and pi/2
the definite integral is solvable with those limits. but not this one
Huh
dont believe me?
yeah you not gonna solve that boy
yeh where'd u see this integral?
it wasnt a definite integral?
can you show with full context?
Closed by @subtle prairie
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 a bit confused about something
Please don't occupy multiple help channels.
hey
whats up
for proving [
\grad\8{fg} \overset?=f\grad g + g\grad f
]
How am i meant to treat [
\8{\vc x,\pdv{!x} +\vc y,\pdv{!y} + \vc z,\pdv{!z}}(fg)?
]
I dont think this is like multiplication so idk how to progress
what is not like multiplication here
you mean the operation between x d/dx + y d/dy + z d/dz and fg ?
@torn jolt
yeah
like thats just composition rather, right?
which level of education u curently doing ?
yeah it's like function application
yeah
(x d/dx + y d/dy + z d/dz) takes a (scalar) function as input and spits you out another (vector) function as output
so like how do i go about proving it if i cant directly modify the expression grad(fg) by writing it in terms of its partials
you can distribute that operator tho
(x d/dx + y d/dy + z d/dz) (fg) = x d(fg)/dx + y d(fg)/dy + z d(fg)/dz
ok yeah fair enough
so you're left with just the three partials
and just product rule it
yah
ok this was uh just like a stepping stone for the actual problem i want to solve
that is
phase 2
,, \grad\8{\vv A \vd \vv B} = \vv A \cross \8{\curl \vv B} + \vv B \cross (\curl \vv A) + (\vv A \vd \grad)\vv B + (\vv B \vd \grad)\vv A
so uh 
how do i do this without crying inside
$\vv A \vd \grad$ is the directional derivative btw so nothing fancy over here


are you just verifying this in cartesian
i mean
thats a question of if i want to be a normal level masochist or an above average l evel of masochist


i mean
its not actually enlightening at all 
you just uh
expand the whole thing out
and verify that the LHS and RHS are equal 
bruh thats why this fucker is so useless
who the frick cares about the GRADIENT OF THE DIVERGENCE
the divergence of the gradient is where its at

ok anyways ill just algebruh it out no biggie
thanks @kindred grove @topaz valley
.close
Closed by @pine dove
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.
$\Phi$
artemetra
this?
chriseubjr
cdf
cumulative distribution function
it's what you use to find P(Z > ...) and stuff
Closed by @fallen osprey
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.
if f(x) = x^3-3x^2+1 i need to solve the inequality f(3+x^2) > f(2+2x^2) and the previous question was to examine the monotone of the function so i thought i need to take cases on each monotone interval but i may be doing something wrong
can someone help me
did you try to develop the expression ?
it is going to be a high degree polynomial
i may have found the solution. x^2 + 3 >= 3 and 2+2x^2>= 2 so both terms belong to the interval [2,+inf) where f is increasing so i can solve the inequality from there?
can you check
@maiden current Has your question been resolved?
Closed by @maiden current
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.
@acoustic sphinx Has your question been resolved?
no
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.
Could you please help me work out the general equation for this pleas
@silent moss 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 sinx be considered a constant?
and move it out front?
probably not right cuz it has an antiderivative...?
or you cant because sinx =/= cosx?
Im not completely sure here but try using U substitution for this, and no you can't move sin to the front
ok yeah its actually really simple using u sub, if you aren't looking for a way to solve this and just wanted to ask the sin question, then yeah its not possible to pull it out of the integral.
Closed by @round rapids
Use .reopen if this was a mistake.
Can you help me with this
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, The AP calculus BC exam is coming up and I am struggling with the content. I only got a 2 on my practice exam, and want to know the best resources to study and help me understand. Any websites, books, or particularly helpful youtube videos that people used would be great!
I know that if there's any specific things you're struggling with Kahn academy is a really good resource
Which is what I have been using all year
also I know it sounds self explanatory but just doing more practice tests can be super helpful as well
Khan hasn't been working very well for me personally, I think I want to do another practice test, but I want to try to change things first, I don't think I'll get a very different result if I try it now...
@drowsy rain help me with this
no not really, I know that isn't very helpful, but I took on too much this year so I'm just generally behind.
I'm not really qualified to be a helper but you could try multiplying everything by (x-9)(x-3)(x-4)
no that's super fair, how about different parts of the test
was it the mcqs frqs?
we weren't allowed to keep the tests since its collegeboard material, but I think I struggle more on FRQs than mc
I think
somewhere I have a test from a couple years back in document form
that you could go through stress free
if that would help
that would be helpful for later, thank you!
Let me grab it rq
that should be the whole thing
and I also have a practice FRQ
Aren't all of those released by collegeboard?
@drowsy rain Has your question been resolved?
Closed by @drowsy rain
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.
hey, can someone help me answer like why does (1+a^2/b^2+a^4/b^4...)=1/(1-a^2/b^2)
.close
Closed by @peak ember
Use .reopen if this was a mistake.
Tysm I got the answer 🫶🏻
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.
In a triangle of vertices A, B and C, consider the point X on the segment AB which AX = 2XB and point Y on the segment BC which BY = 3YC. Let P be the point of intersection of CX and AY. Write vector AP as a linear combination of vectors AB and AC
A: ||2/9AB + 2/3 AC||
@gentle coyote Has your question been resolved?
<@&286206848099549185>
@gentle coyote Has your question been resolved?
@gentle coyote Has your question been resolved?
@gentle coyote Has your question been resolved?
.close
Closed by @gentle coyote
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.
guys
in a mirror
the reflection
of a hooman
is the inverse function?
0:
the mirror is 2D rightt
@torn jolt 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.
is this right 
OMG WTF IS THIS
Can you shade the region common to T,R, C?
🙅♀️
ok, what's the region common to T and R
Think about why this is the answer
do you know what the ∩ symbol means
.close
Closed by @vivid berry
Use .reopen if this was a mistake.
great answer
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 many roots in X² = 0
Just one root, x=0
but it has multiplicity of 2
yep
0 × 0 ?
(x - 0)(x - 0) = 0
Closed by @idle shale
Use .reopen if this was a mistake.
all good :)
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... How did this turn into this
a^2-b^2=(a-b)(a+b)
np
.close
Closed by @timber juniper
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 factorise this
you mean factorize 2x^2 + 9x + 9?
(x+3)(2x+3) lol
what is the original function
I think its 18x^2 not 16x^2
my eyes are blind
How’d u get that tho
it's just the regular factorization gimmick?
,, (2x + ?_1)(x + ?_2) = 2x^2 + (2(?_2) + (?_1))x + (?_1 \cdot ?_2)
nyxie9151
the
this lowkey confusing tf outta me
=2x^2+9x+9
=2x^2+3x+6x+9
=2x(x+3)+3(x+3)
=(2x+3)(x+3)
ohh oaky
@tropic yarrow 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.
what is the area of the square? (cm)
Please don't occupy multiple help channels.
I closed the other one so it should be fine.
Decimal points
Start by noticing that the smaller triangles are similar, that should allow to solve for their sides
the numbers mason50_50…
the numbers mason50_50…
the numbers mason50_50…
Which equates to 73.5
cm
Then subtract the area of the two inner triangles from that area of 73.5
I'm confused by what you did sorry
by the way, the square is NOT in the middle of the hypothenuse line.
I see
I got this on a 10th grade maths test.
Did u get it?
no sorry
The area of all three equals total area of triangle
The area of square is (root x)(root x) equals x
yea ik
that's why I wrote sqrt x
we don't know any values though.
Base is 14- root x
OH
Same for upper triangle
yeah
that makes so much sense now
on the test I literally measured the length haha
I didn't have any other choice
0.5 x (root x) x (10.5- root x)
answer was 36 cm^2
What the
That is not possible if the diagram is not to scale
well my professor said that it doesn't matter how I do it, just that I show how I do it.
Don't tell me you drew the triangle?
I made it to scale on papper.
haha yes
but I believe I got every other question right
Well, it isn't wrong
so probably still an A.
Just that it takes time
That's good
yeah I know
I used laws of cosines when I just had to use the pythagorean theorem 😂
But for me, they'll reduce marks if I do your way
yeah I know that
Bruh
but hey at least it's not a 0 score.

Closed by @limpid monolith
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 confused are they asking for the concavity here or what
i did concavity and it was wrong it must be asking for something else
show work
for local min/max, you'd want to determine location of stationary points using the first derivative
and first derivative also tells you when a fucntion is increasing/decreasing
x=0 and x=2
and then you can plug those values into the second derivative to determine what kind of stationary points they are
@quiet tundra 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 am wondering if someone can help me with some Discrete math questions! Thanks so much
Thanks, im unsure how this is wrong
I haven't studied this yet, so I can't help, sorry
Its just logic?
Assume the statement “No one loves spinach” to be true.
Would that mean “Someone doesn’t love spinach” is false?
If at least 1 person loves spinach then it must be false (negation) to conclude "No one loves spinach"
@loud ferry 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 someone, slide me a hint to calculate for y ?
hint: collect like terms, separate constants from variables (sqrt(ab) = sqrt(a) * sqrt(b) is good here)
so i get something like this: 11\sqrt{2}\sqrt{y} = 2(8\sqrt{2}\sqrt{y}) - 5
yes
indead
well nvm i figured it out thanks 
@rain briar Has your question been resolved?
Closed by @rain briar
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 i have a problem in this question. I'm attempting it like this,
for your information, there is an integrated texit bot here and u can surround ur math with dollar signs to produce an output
whats your reasoning for doing
\frac{576}{25} - \frac{100}{9} - 2
i thaught when we need to find how many numbers are between 2 numbers like 1 and 10, so there are 8 numbers in between. We subtract 1st and last nnumber and then subtract it by 2 to get all the values in between ?? 
subtracting by 2 doesn't even work for integers
yea i just realised it.
and also you want for first consider either the floor and/or ceiling of your fractions depending on personal preference
@rain briar Has your question been resolved?
Closed by @rain briar
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.
Closed by @queen jetty
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.
Closed by @livid herald
Use .reopen if this was a mistake.
.reopen
@livid herald Has your question been resolved?
@livid herald 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've been stuck on this question for a decent while.
I tried making a venn diagram but it was useless.
can you show the venn diagram you tried?
you can let some variable be the total amount of people, then solve for k
x = total
k% of x = ??
oh like 0.6x + 0.5x + k%(x) + 10 = x or smt?
yeah
@rapid siren Has your question been resolved?
<@&286206848099549185>
@rapid siren Has your question been resolved?
<@&286206848099549185>
your 50%, 60%, and k% are wrong
doesnt "50% participated in at least hiking and canoeing" include the 10 students participating in all three activities? so my venn diagramm would look a little bit different.
yeah, that's what i mean
as you have "at least" thsi woukdnt be an equality
a+b+c+10=x
a+10>0.5x
and so on.
and you know that a,b,c,x must be natural numbers.
@rapid siren
Closed by @rapid siren
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.
My notes are unclear what to do next
Please don't occupy multiple help channels.
@long bloom Has your question been resolved?
.close
Closed by @long bloom
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 tan (360 - theta) = tan theta
why isn't tan theta negative even though tan is negative in QIV
Closed by @nocturne garden
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.
That's the question and I know I need a system of equations, however I can only come up with these but they give me a negative answer which I know it cannot be, any tips?
A nice way to find more equations is noting that the sum of each probability*Tokens awarded = 11
and the sum of each of the probabilites = 1
aka a ball will be pullled out
Hmm, lemme try that and get back to you
Same problem, it's still negative
We know that m has to be positive since that's also the number of red balls so the unknowns are all positive
@livid herald Has your question been resolved?
@livid herald Has your question been resolved?
Anyone who can help?
Hey
The second equation is wrong?
First the probability of white will be $\frac {15}{4m}$
Monarch of Eternal Night
So token will be $\frac{(15)(m)}{4m}$
Monarch of Eternal Night
And probability of yellow toke will be $\frac {(5n)(23)}{8m}$
Monarch of Eternal Night
I'm sorry can you explain how you got this? I'm on a serious mental block
I get the next steps you've done
The probability for red ball
It's $\frac {m}{6+m+n}$
Monarch of Eternal Night
Yea
Which equals to 5/8
Yes
So $6+m+n =\frac{8}{5m}$
Monarch of Eternal Night
And for probability of white is $\frac {6}{6+m+n}$ just substitute 6+m+n
Monarch of Eternal Night
@livid herald
Sure np
.close
Closed by @livid 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.
Hey is this correct?
@terse dove 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.
Let there be $f(x) = ax^4+bx^2+c$ $(a, b, c \in\mathbb{R},a>0)$ such that $f(x)$ has 3 extrema at 3 points A, B and C$\left(1,-\frac35\right)$. Let there be $g(x)$, a quadratic function having the graph passing though A, B and C. The region confined by $f(x)$, $g(x)$, $x=0$ and $x=1$ has an area of $\frac25$. Evaluate $\int_0^1 f(x)\dd x$
rough diagram
Wow
not sure where to go from here
What is the range beside C
what do you mean?
Yeah
the problem is i dont know B
Hm
(0, c)
yeah
oh wait
If there is max or min it should give 0
yes
this feels like a problem you posted a long time ago
satisfy it with A and C to get a, b