#help-0
1 messages · Page 424 of 1
Yes
Just think of it like this
ohhh
Those are brackets btw
Closed by @vivid badge
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.
why is k = -2 and not 2? where is the negation coming into play?
-k=2?
i dont really understand that phrasing
a negative before the variable name
i understand k = -2
you mean --2 = -2?
What’s wrong with -k = 2
-k(where k is -2) = --2
That’s not right
is there implicit simplicification happening here or something
why do you go from (y-k)^2 to y+2
makes sense if k is a negative already. then double negative is positive
but is k always guaranteed to be negative in this equation
nope if the eqn had y-2 then k would would have been postive
can you say why -k goes to 2 exactly
i feel like an explanatory step is being skipped
like some translation is happening
ok i think i get it. You are obvserving that the standard form is x - something, y - something. So the fact that the equation they show us is y + something, means that the original something must have been a negative, making y - something a double negative thus y + more simple
exactly
i am sorry but i could not explain into words as i did not understand what you meant at first
no worries you helped me get there
aight
Closed by @rugged cosmos
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 know the differential equation is separable, but we were asked to solve it as if it was a linear non separable one
But we have no idea where it went wrong
(the integral at the end is incorrect)
y' - 3x²y = 6x²
ok
I know the solution, just have no clue why solving it this way leads to nowhere
y = -2 + e^(x³)
@magic arch Has your question been resolved?
this differential equation is not separable, you have to use the integration factor
it is tho
y0shi
if you move the y term to the other side
yea
there is no way to factor out a y
so it is
y0shi
y' = 3x^2 (1+y) ?
well it’ll be 2+y instead
y mb
yes
as ive said
i dont care about the end result
my question is where did it go wrong
it should be solveable the way we started
your C’(x) is wrong
and honestly i’m not sure if you can solve it using homogeneous and particular solution, but you probably can
y0shi
oohh
yes
cuz
f(g) * g' has a primitive
so
6x^2 / e ^(x^3)
where
x^3 = g
and we get
-2 * e ^(-(x^3))
@magic arch Has your question been resolved?
Closed by @magic arch
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 dont get this lines
the solution to the box will be the answer on the line u need to go to
for example if the answer to the first box of 6, you would go down
if it was 5, you'd go right
the answer is 2 thats why i dont get it
so its 5?
why does it has to be least to greatest?
these metrics we use, mean, median mode, are all about finding the "center" or "average" values
if we had a sequence
9, 9, 2, 9, 9
the median is 2
however, thats not helpful, because everything else is a 9, thus the 2 is a bad representation of the actual sample
or if we have
10000, 3242, 12342, 9, 3282, 8779, 87721
the median is 9
"is 9"
but we havent ordered it from least to greatest
the median is supposed to give you a good "center" read on the sample
9 doesnt do that at all
in range does it has to be least to greater also?
range is just greatest number - least number
for this, range would be 9-2
for this itd be 87721 - 9
Closed by @true dagger
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 guys, i'm currently learning proof by induction and the video my uni gave me confused me. i've watched a couple of other videos now and i think i understand it a lot better, however the original video confused me. when we're aiming to prove that LHS < RHS for k+1, what's with the additional steps, is it not just enough to say that because k >= 5, that for all cases (k+1)^2 < 2^(k+1)
this is the video if you wish to take a proper look, i've timestamped the start of the question https://youtu.be/So-Sd5K7PgE?si=SE7tEsctEtOSX7Ob&t=367
it's a terrible wording, instead of saying suppose k>=5 and P(k) true, they should suppose P(k) true for some k>=5 (but not necessarily all)
For the case of considering k, you actually consider it to be true, assuming it to be true then gives you the motivation (normally using algebra) to prove that "Well if the number before it is infact true, then this case has to be true" That is the motivation for everything after the green text
ok that explains it
i believe they're more specific in the video
why does it suddenly go from k^2 +2k +1 to k^2+2k+k
i know it's obviously greater
but why go in that direction
Effectively you are supposing that if you can prove that something is true if it's previous step is true this means that everything up "k" is true
yea i remember that about induction
It's an inequality for the convenience of proof since we know that k^2 +2k + 1 < k^2+2k+k and that k^2+2k+k = 2^(k+1) which is of the same form of the required proof
Effectively this inequality just proves your statement
okay so it's shifting it into the same form as the inequality in order to show that it's greater
This statement is trivially true and it allows us to prove the more general statment that:
(k+1)^2 < 2^(k+1)
okay gotcha
Which is what you are required to prove
is this particularly just for inequalities
i've practiced a lot of others and the ones making both sides equal seems far esaier
This property is most useful with inequalities
okay gotcha
thank you :)
is there any chance you could quickly look over one of my proofs
Sure
seperate proof by contradiction just learning proofs and not too confident atm
Send it through
most other people i spoke to chose to expand the quadratic out and then determine the parity of each part of it so you end up with like even + odd = even contradiction
not sure how much my proof relates to z being irrational in the original statement tho
For this contradiction you really just want to assume that z is rational for odd a, b and c and then prove that this cannot work
okay so that would be by expanding further before rearranging
then determining parity of each part and concluding that for rational z, a, b and/or c must be even
?
You can certainly do that
It's normally that a and b are of the same parity and that c is odd
Just as a hint
yea ok that was my original plan but i found the implication thing messing around
ahh okay cool
from a marking perspective do you think this proof is inherently wrong?
And just remember, if x is even x^2 is even and if x is odd x^2 is odd
yea cheers
Certainly not, rather it may miss what the question expects you to do, which will see you lose marks irrespective of wether or not your proof is true
ok gotcha
I ran into the same issue in 1st year with vector space proofs, I would prove it say using properties of triangles, rather than properties of vectors because the question constructed a triangle, and this would see me be decucted even if my mathematics and wording were perfectly adequite for a perfect score
alright will keep that in mind
will redo it if i get time but probs not
thank you so much for your time
i'll probs be back in like 5 with another induction question
Feel free to @' me
sure
@lime garden Has your question been resolved?
Closed by @lime 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.
what have u tried
i have integrated it to x^4+ k/2 x^2 +c
not quite
$\int 4/x^3+kx :dx=\int 4x^{-3}+kx: dx=\frac{4x^{-2}}{-2}+\frac{kx^2}{2}+c$
Max
ah ok
@near hollow i am not sure how i'm ment to get the vale of k tho
oh weight its not asking for me to
sorry silly
thanks
.close
Closed by @fleet grove
Use .reopen if this was a mistake.
✅
yes?
okay
just add the bounds to the integral
$\int_0^2 4/x^2+kx:dx = \left[\frac{4x^{-2}}{-2}+\frac{kx^2}{2}\right]_{0.5}^2=8$
Max
then you sub in and take away thing
yea
is it the top number - bottem?
so like the 2 subbed in squar brakets - 0.5 subbed in squar brakets
yea
i subed it in and now im confused a bit sorry
what did you get after you made the substitution
I did the square bracket thing with subbing in the 2 and 0.5
@fleet grove Has your question been resolved?
yeah what did you get
preferably show us your working
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
my current lesson is about using derivatives for related rates and optimization
im having a hard time with it esp on this problem, could someone guide me through the solution
@magic falcon Has your question been resolved?
hey, im new here so i dont really know how to proceed, but imma try my best to help
I think u are supposed to develop a function related to the volume of the cone and derivate it to obtain the speed and acceleration at which the water rises, and the same for the radius of the balloon
this is where i ended and i dont really know how to proceed from here
i think i should equate negative dv1/dt to dv2/dt
Ok, so the problem is asking you to derivate w/ respect of t, which u dont have in the equation of volume
But you can put both the radius and height as a function of time using the information the problem gives
Bc in this case height and radius are not constant
I dont know if im properly explaining myself 😅
Is it okay to explain Calculus to a 5th grader?
I mean, this is what this server is for isnt it?
r1 would be 2
h would be 6
I don’t have an idea on what to do regarding the other variables
I am in a situation where I have to teach my friend's son, for a math competition, now I am just asking if a 5th grader can pick up Calculus and understand it deeply.
Anything is hypothetically possible - it's question of many variables, though.
oh ok, i didnt understand the question srry 😅
Ah okay, I am very new to teaching and I don't really know a 5th grader's limits.
My prognosis is not optimistic, but it does depend on the amount of time and patience allowed.
The competition is in 2 weeks.
What exactly would you plan to teach in calculus?
I'm not sure, I haven't seen the questions yet in the warm-up tests.
gimme a second. im grabbing my notebook so i can explain it visually to u
thank you
Check this out while I write the next explanation
As u see I borrow the equation of motion to get height as a function of time
Also at the very end whats cut off is h = 0.2 t
but 0.2cm/s isnt like a constant throughout the whole process, only when the water level is 5cm deep
i was thinking i need to somehow get dh/dt from that information but i have no idea how
r1 is 2
h is 6
r2 is 1
the unknown is dh/dt and dr1/dt to solve for dr2/dt
im not quite sure what dr1/dt represents
i know dh/dt represents rate of water level increase within the cone, for dr1/dt i dont get because r1 is already a constant?
dr1 is the derivative of the radius w/ respect to t, but to do that you need r as a function of t
wait wouldnt it just be 0? the radius of the cone will never change
therefore rate of change is 0
hmm
dr1 is not a constant. they just give u the height and radius of the cone so you can know the angle of the generatrixes
i meant r1 since r1 refers to the radius of the cone, 2, which doesnt change
Ok
so i was thinking it cant have a derivative if its a constant
so
Nono
dont worry
This is not an easy problem
Let me make a sketch to simplify the problem
with this logic that must mean dh/dt is also 0 because the height of the cone also does not change
which makes the right hand of the equation equal to 0
so im probably not right at al
i realized i havent taken this into consideration yet
trying to figure out where this info fits in
Ok, so we maybe shoud have started from there
do i need a new variable for water level?
W is the rate of water right?
dw/dt is the rate of which the water level in the cone is rising
whilst w itself represents the water level height
i think(?)
so rises .2 per second when 5cm deep
dw/dt = .2 when w = 5
wait then ill need another variable for the water leaking onto the balloon or rather the rate of water entering the sphere
i am so lost
i just took it from the hint
oh man i dont get anything anymore, i missed that first negative sign at the top
that might be it
anyway
i think ive never solved a problem the way your doing it
i guess bc ive been taught differently
ive been taught to just equate the derivatives
and plug the variables in
could u solve it the way u would solve it?
ok, lemme try
@magic falcon 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 dont even know where to start
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.
so how would you figure this out without actually solving the integrals. I assume the answer is false since if you switch the intervals you would have to make the function negative?
@gilded galleon Has your question been resolved?
@gilded galleon Has your question been resolved?
Draw the region
Is it a simple region?
If so then you can swap the order of the bounds hence they are the same
Otherwise they are not
ok so its true since the region is a box and it doesnt matter the order you integraet it in since they are just constant bounds
for some reason i thought the intervals were switched too
.close
Closed by @gilded galleon
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 can I find the angle θ?
only info youre missing is the radius, then you should be fine using soh cah toa
The radius is sqrt(5)-1
then thats your hypotenuse
I don't know the other angle though, or the third side so I'm missing something from soh cah toa
?
to find the angle you only need to know the lengths of two sides of that triangle, which you do
I need the length of the long side to do that though
I only know the length of the short side
i just told you the long side is the radius
^
@stark flicker Has your question been resolved?
Closed by @stark flicker
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 do i do here?
hey using this channel already :))
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).
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
I'm not really sure what to really do here. I've been brute forcing to find f(x,y) and not really sure what bounds to integrate by
@whole scaffold Has your question been resolved?
<@&286206848099549185>
path independent means you only care about the start and end, it's f(5,1)-f(1,0)
so i just integrate one from 5 to 1 and another from 1 to 0?
but which variable od i integrate by?
you did the integral already
gradf = F is basically derivative of f = F, so little f is the integral equation already
like
my integral is y^2+(x^2)(e^-y)
what variable do I integrate by, cuz i have x and y
oh like
i just evaluate?
oh
so i know i should probably make a new channel but what about this one
is it just the same thing?
i just repalce x and y with the parametric formula and just plug in 1 and 0 for t?
instead of integrating from 1 to 0?
not sure what you mean, but you find the start and end and do f(end)-f(start) again yes
just from the parametric part with t
Closed by @whole scaffold
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.
have i done this question right?
other than that looks good
Closed by @primal thicket
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 am I unable to graph this onto my calculator?
I'm able to graph tan(pi/x) but not xtan(pi/x)
also how would I have found the asymptote?
compute the limit of the function as x->+inf
wth is that 😭
I can graph tan(pi/x) just fine it shows what the answer shows but if I graph xtan(pi/x) it doesnt show anything
https://www.desmos.com/
use this website 

i wont have that during the exam bro what 😭
its a graphical calculator
i have to use
calculator issue
hmmmm. post input and output 
then idk
okay forget about that then
but like
how would I have found the asymptote
to equal pi
just look at what it is for large values of x
oh yea ur right
sub in a large value and i get 3.14 so its pi
my calculator graphs tan(pi/x) just fine and it shows what the answer shows so i'll just simple shift the graph up and add an asymptote at 3.14... simple work around
thanks for the help
appreciate it
.close
Closed by @karmic saddle
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 tell me how to proceed
what is y_2 and y_1?
maybe the subscript is the p
thats my question too
just a guess tho
the first derivative of y wrt x (bad notation)
well plug y = cos(pt) into this
its using the pythag trig identity
oh shi
to write sin in terms of cos
Closed by @wintry sluice
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.
.open
Need to find out if xsin(1/x) has infinite number of maxima and minima on the interval (0,1)
You can prove by limit as x approaches zero, the frequency of the oscillations of sin(1/x)) increases to infinity, leading to an infinite number of oscillations within the interval (0,1)
Since for every period of oscillations return 1 local max/min
then u also need to prove that these local max min doesnt = to each other
near 0, x=0
take the infs and sups
x*sin so x acts as altitude
that is true
and start by considering the subintervals x in [1/(4pi n), 1/(2pi n))
so only way to prove it by showing that the given function oscillates too much, and hence there are infinite number of extremums ?
Not too much
as x approach 0, the period approach 0
I mean infinitely
it does
Oh not local
but using the derivative tests, can't it be shown ?
Global
Hmm
what derivative tests
first or second
[ \frac {d} {dx} xsin(\frac{1}{x} = 0 \ ]
We can use it, then it repeat the very arguement that we made from the start
yes I was trying to do so
no
the assumption is f has a local min/max
not that f' = 0
the converse isn't true
[ \frac {d} {dx} xsin(\frac{1}{x}) = 0 ]
shanks44
you can't just say f' = 0 for inf many x in (0,1) implies f has inf many min max
no but solving the equation f'(x) = 0 ?
i mean you can if you want to get an idea of what's going on
but if you're asked to prove it
then you need to prove it
[ xcos(\frac {1} {x}) \frac{-1}{x^2} + sin(\frac{1}{x}) = 0]
shanks44
please don't solve for x
what you're doing is not a valid proof
oh, I don't get it, may you explain ?
intermediate value theorem
ok
and this part also
do you know what the statement of the theorem is
oh, let me quickly check
the assumption is f already has a min/max
you're assuming f' = 0
you can't apply this theorem
but I was thinking about finding out all the critical point
and then what
so at critical points the given function will be horizontal
why
that is some local extremum is present
you're assuming the converse of this statement is true
which it is not
ok
but what about this fact ? I know I am missing something very basic
slope of the function will be 0 right
the statement only works one way
IF f has a min/max THEN f' = 0
it is not true that
IF f' = 0, THEN f has a min/max
what is the derivative of x^3 at 0
0
is there a minimum/maximum of x^3 at 0?
actually neither
ok, I am getting some of it
so the only way to show that the function has inf. number maxima and minima, is because the function oscillates infinitely then
i mean
im sure there's another way to prove it
but taking all the subintervals [1/(4pin), 1/(2pin)) is the most obvious to me
what is 1/4pin ?
chebyshev's infinite pee norm
yes
and why choosing the sub intervals in that specific way ?
anyway thank you both @wraith stratus , @wanton peak
You haven't finished it yet?
yes as you suggested the first way, by showing the inf. no. of oscillations
I found out that f' = 0 cannot be used here
also why semi open intervals ?
open intervals also serve the same purpose right ?
yh
ok, so the entire (0,1) can be split in (1/4pi,1/2pi), (1/8pi,1/4pi) and so on
and we need to show that each such sub interval has an infimum and supremum
so there are infinite numbers of extremums
right ?
@wraith stratus ?
yh
yes yes
but ye
.close
Closed by @cobalt 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.
can you give an example of 2 functions where :
$\ \lim_{x\to a} f(x) = \lim_{x\to a} g(x) = \infty$ and $\lim_{x\to a} \frac{f(x)}{g(x)} = 1$
Adam Chebil
x^2 + x
x^2
do you want a to be a finite number
no
can you give an example wher lim f = lim g = 0
1/x^2
1/(x^2 + x)
is this possible :
$\ \lim_{x\to a} \frac{f(x)}{g(x)} = 1$ and $\lim_{x\to a} f(x) = 0$ but $\lim_{x\to a} f(x) \neq \lim_{x\to a} g(x)$
Adam Chebil
can't think of an example off the top of my head 
im guessing no because if the limit of g is any other real number it would be 0 and not 1
i was thinking about this yesterday
backwards lhopital gets you lim f = lim g
but obviously can't assume the converse of lhopital
but i couldn't come up with any counter example as well
I'm trying to verify if this statement is true for all functions f(x) and g(x) such that lim f and lim g exist
but i'm guessing it's not true if lim f = 0 or lim g = 0
@frail grove Has your question been resolved?
@frail grove Has your question been resolved?
Closed by @frail grove
Use .reopen if this was a mistake.
✅
Closed by @frail grove
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'll try to translate this the best I can, but I'm supposed to calculate the coördinates of point A and B. while trying to coördinate point A, I bumped into a small problem on where I didn't understand why t = 5/6pi. Why isn't it 1/6pi or 1 1/2 pi instead? I was just wondering, since they're within the given domain(?is that how you call it in english) too
i basically understood everything up until the last step, so if anyone can explain it to me i'd appreciate it alot!!
@dusk cave Has your question been resolved?
.close
Closed by @dusk cave
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.
hopefully these questions too much, but I'm confused on how a converges. When I do the ratio test, I obtain $\abs{-5}$ which is 5 and thus does not satisfy the ratio test
parakeeti
parakeeti
I think I messed up the latex thing, but it cancels out to just (-5)^1
should be c_(n+1) in the numerator
the problem is you don't know what c_n is
what if it's 1/42^n
that makes sense, but if we don't know what Cn is, how can we conclude anything from it
well you're given that sum c_n 7^n converges
the ratio test should tell you something about the limit of c_(n+1)/c_n
do we have to find r
you can't know r for sure
what I'm suggesting is using the ratio test in reverse essentially
comparison test?
you know the series converges
oh lol xD
so |r| is less than 1
could we multiply c_n on both sides
wait
nvm
doing so would get c_n+1 < cn
$r = \lim_{n\to\infty} \frac{c_{n+1}7^{n+1}}{c_n7^n}$
aPlatypus
that thing has to have absolute value less than 1
parakeeti
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
just use paint if latex screams at you
I think I understand it now, there was a video with the web-assign
I'm a little confused on where -4 < x < 4 comes from and why it's not just {4}, I'm assuming it's because when ur doing the ratio test x is abs value right
it's the domain where you know the power series converges
so pretty much yes
okay, that makes sense
my brain is so fried
so much calculus today
but thank you
.close
Closed by @fluid moon
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 know when to use p equals p primed and ek equals ek primed
I don’t know how I would know that Batman’s final velocity is solved with p equals p primed
your starting point should always be conservation of momentum as it is always valid and a safe thing to do
Conservation of kinetic energy is only true if we assume no energy is lost in any other form (heat, sound etc)
In this case, you need both because you have 2 unknowns (your number of unknowns has to be equal to the number of equations)
So if you are given no idea of the final velocities/momentums/coefficients pertaining to how the collision took place (which I imagine you haven't done yet so dw about it), then the second thing to do is to consider Ek
I just don't know which formula I employ for which collision object
Does it have to do with the magnitude of V or the mass?
It shouldn't matter, provided you're consistent with which way is positive in the case of momentum
I think the red arrows are probably confusing you
Ignore them
It doesnt matter though
But I don't think it matters though
You use both for both objects
m1 and v1 relate to car 1, m2 and v2 relate to car 2, put 's on the vs and it relates to the final velocity of 1 and 2
Just be consistent with your notation
We know that v1 and v1' are the initial and final velocity respectively of car 1
yeah
Closed by @sour sphinx
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.
pls help
with?
why can't the mean be: 25/5
of?
👀
yes?
Why can't the mean be: 25/5
I don't understand! Just why not!?
Why do we need to multiply the capacity with the capacitors to find the sum then count the total of the capacity!? Why not just take the sum of the capacitors over the number of the capacity?!!!!
JUST WHY NOT.
[6(21)+5(24)+3(27)+5(30)+6(32)]/25
we want the mean of the capacity, so we have to add all said capacities
Not what I was asking for 😡
on what basis
I dont want [6(21)+5(24)+3(27)+5(30)+6(32)]/25
Logic
Just count the number of capacitors= 25
over the number of capacity (the x axis)= 5
why on earth would that work, that would just give you the mean number of capacitors for each capacity
yes thats how it's supposed to go like
Like why not?
Why not my solving?
i dont understand why you believe that would work?
at least i dont see the logic behind the thinking
sum/25 is capacity/#each capacity
What about the logic behind your thinking
sum/5 is capacity/#each type of capacity
proof?
the logic of mine is i summed all the capacities and divided it by how many capacitors there are
thats the definition of mean value
what-
prove mines didnt sum all the capacities and divided it by how many capacitors are there
you took the number of capacitors and divided it by how many values of capacity are available
Prove that
whats the basis of that giving you a mean capacity if you didnt even use capacity
mean capacity with respect to capacitors is amount of capacity/number of capacitors
mean capacity with respect how many types of capacitors is amount of capacity/number of different types of capacitors?
the capacity is the many values of capacity that were being used at the denom
HEADACHE
bruh
5 isnt even a capacity
that's why i put a question mark, maybe you seeing it that way?
youre saying 5 as in there are 5 capacities
what way?
but thats not the capacities themselves, just how many unique values of them you have
total no./sum of capacity: 5
25/5 would be the mean number of capacitors for each capacity
thats completely correct?
thats not what it asks for though
it asks for the mean capacity
of all the capacitors
thats what its asking bruh
mean capacity? so two equations?
well it says "capacities w.r.t capacitors", not "capacities w.r.t types of capacitors"
im just going to step away
all im saying is it wants the mean capacitance thats it
good luck
capacities = 25
ok? i gave him the capacitance
good luck for you too
ok im out too
alr bye
just "disassemble" the diagram
it never says you need to organize them by 4uF, 7uF, 10uF, 13uF, 16uF
in total there are 25 capacitors
and each capacitor has a unique capacity
disamble?
thatswhat i said
ok? and how you define mean?
sum over total
5
that's the number of TYPES of capacitors
know what the answer is 59159190610369
?
bye
It's the best one I could screnshot
Yes.
I seriously can't read this properly lmao
Then don't
what's being said here?
microfarads greater than the capacity of each
I see
But you don't
Here.
Mean value : 25/5 ❌
25/5 not correct answer
yeah it isn't
It is?
why would it be?
that's mean for amount of capacitors
^
and you need mean for capacity
they want that
it says mean for capacity
same thing
they are not the same thing
can u prove it
capacitors have capacitance/capacity
then?
I have a bunch of capacitors.
that was my last contribution apart from reactions, salut
I want to find out how good they are on average
ok
ok suppose you have power, engines and different types of engines
what u doing is mean for engine/different types of engines
not power/engines
what's the difference?
$amongusamongusamoagnawuigigh69834 ihu609ytwi 094y$
svc
Clearly understood that.
the mean is the sum of all the capacitors' capacities, divided by the number of capacitors
you have 5 types of capacitors
each type has a different capacity
Oh okay
you want to sum up all of their capacities to get a total capacity, and then divide that by the number of capacitors to find the average capacity
Thank you for your clarification 🥰.
...does that solve your problem?
Closed by @humble totem
Use .reopen if this was a mistake.
i dont know what to say
me neither
I don't even know where the confusion lay lmao
I guess in the definition of mean
No, it's just that the other two prolly never once presented for class
.close
@paper mango go away
(jk)
Keep in mind that independent of other's backgrounds, everyone helping here is sacrificing their free time voluntarily to aid others with problems they're likely too good for. Mutual respect is the least I'd ask for.
? 😭
you're aware what I refer to
Not everything has to be taken serious btw.
what does this even mean
Class presentation
the other two have almost certainly done presentations before, but I don't see why that's relevant
Dw I've got you
not sure what you mean
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'd like help on this problem please!
I have no idea where to start, what formula to use, or just how to go about this problem 😦
one second I got you
tysmm
Here we will likely use the intersecting secents theorem
(in case you need it https://www.varsitytutors.com/hotmath/hotmath_help/topics/intersecting-secants-theorem)
Math homework help. Hotmath explains math textbook homework problems with step-by-step math answers for algebra, geometry, and calculus. Online tutoring available for math help.
Let me know if you need any more help
TY!
@gilded nimbus Has your question been resolved?
Closed by @gilded nimbus
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 was hoping someone could check over my reasoning in my proof for part (b) of this
Just the forward direction of the proof actually
Let $a\in H$ and $b\in K$, then $ab\in H \cup K$ and assuming $H\cup K$ is a subgroup this implies that $(ab)^{-1}\in H\cup K$. So either $b^{-1}a^{-1}\in H$ or $b^{-1}a^{-1}\in K$. If it is in $H$ then by closure $b^{-1}a^{-1}a\in H$ and $b^{-1}\in H$ which implies since $H$ is a subgroup $b\in H$ so $K\subseteq H$. And the argument is the same if $b^{-1}a^{-1}$ was instead in $K$ we'd get the opposite inclusion and hence prove the forward direction.
Austin
Does that work?
no
because you could have some (a, b) pairs for which you show b in H
and some (a, b) pairs for which you show a in K
so you don't get inclusion
What do you mean?
for all (a, b), (a in K) or (b in H)
That doesn't let you claim K in H or H in K
There's no ordered pairs here
I don't understand what notation you're using
let a be an element of H and b be an element of K. I have to show either a in K, or b in H.
you start with "let a in H, b in K"
That specifies a pair (a, b) on which you reason
You do that reasoning for all pairs (a, b)
you have shown that
I claim it doesn't trivially imply inclusion of the whole groups
I don't understand
this might be easier to read
same reasoning
I just typeset
ok then
explain how "b in H" implies "K subset H"
b was arbitrary in K
but for a given pair, you've got one of these
it need not be always the same
you could sometimes show a in K and sometimes show b in H
in which case it could be that you failed to show either total inclusion
well how could that fail ?
I'm not sure
then think more
Your question isn't even clear what I should be thinking about
I don't see why ab\in H U K
if you can formulate how it can fail
then you might see how it can fail to happen
i.e. the failure case is actually unachievable
ab in H by closure of the group operation
assuming H U K is a group, then it is closed under multiplication
assuming neither K subset H nor H subset K
Then you have 2 counter-example elements. What can you say about them ?
there exist g1 in H\K and g2 in K\H
then apply the above reasoning to these g1, g2
and we will achieve a contradiction?
Suppose H U K is a subgroup but for the sake of contradiction that there exists $g_1\in H\setminus K$ and $g_2 \in K\setminus H$. Then $g_1g_2 \in H \cup K$ which under the assumption that it is a subgroup implies $g_{2}^{-1}g_{1}^{-1} \in H$ or $g_{2}^{-1}g_{1}^{-1} \in K$. If it is in $H$ then $g_{2}^{-1}g_{1}^{-1}g_{1}\in H \implies g_{2}^{-1} \in H \implies g_2 \in H$ which is a contradiction, and the same for the other case.
Austin
I assume the thumbs up means yes, but is that now correct Bezier?
ye
it's the same thing, except we showed there's an instance in which this leads to a contradiction
Closed by @vapid shuttle
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 would I solve for a?
Did you differentiate the curved graph?
huh?
@full nimbus Has your question been resolved?
<@&286206848099549185>
start by differentiating the curved graph, which is the graph of y = ax^2 + ....
what does that mean?
it means to calculate y', the derivative if you prefer
@full nimbus Has your question been resolved?
idk how to do that
I think I need to solve it by doing something with the discriminant
you dont need the discriminant to differentiate a function, so you dont need it here
you should probably have a table or a spreadsheet with the common derivatives
I'm in pre calc, idk what that is
.
oh, then im not sure what to tell you
i thought that was how you were supposed to solve that
cant help you then sorry ;/
@full nimbus Has your question been resolved?
just derive it with inspection
if two graphs intersect
they have the same point (x,y)
try plugging in y from the first
into the second
-4x+5=ax^2+(a-4)x+3
and then find a such that it has one solution
(discriminant 0)
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.
Anyone here???
.close
Closed by @twin nimbus
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 apply those fractions to real life problems? I don't understand how to interpret that into a real math problem
Anyone got time for some pre algebra /algebra problems
just ask
its used to make various objects
