#help-36
1 messages · Page 241 of 1
The implication as you wrote it is incorrect
I wrote |x(t)|≤M
Think about what happens if x is very close to 0
So |y(t)| ≤ |log(M²)| so limited constant?
No you can't conclude that
Mmm
Take your time to write down exactly what the inequality |x(t)| <= M implies
y(t) = log(...) you mean
?
Its an example
Yes
Take your time to go through the inequalities' implications one by one
You start with |x(t)| <= M
What can we do to get closer to the expression of y
Yes
|y(t)| = |log(x²(t+1))|
Then what do I have to do?
If I know that |x(t)| ≤ M
s=t+1
You can apply functions on each side of the inequality
So |y(t)| = |log(x²(s))| ?
Take it the other way around
We start with the inequality
And from the inequality, we try to recover y(t)
So we start with this
In y(t), there's no |x| but x²
So what should we do?
I bring the absolute value into the log
Once again, you're looking at it the wrong way. And no, you can't do that
what's inside the log already needs to be positive
How do we go from |x| to x²? What's the link between those two quantities
But if I can't get |x|≤M, how can I write x as M? Then it's not stable because I can never get |x|
|x| ≤ M -> |x|² ≤ M²
x • x*
x is a complex function now?
No
So |x|² is x • x
You know how to take the log of any complex number?
I only know that x:D->R or x:D->C
Let's assume x is real for now
If x is complex then you can take x = i and the log makes no sense
if x(t) = 0 the log is not defined => not stable?
From here you get y(t) <= log(M²)
And not |y(t)| <= |log(M²)|
I can't apply ABS both sided?
.
In the definition it is only written |x(t)|≤M
I Need a lower bound
<@&286206848099549185>
@scarlet sequoia
@scarlet sequoia maybe he can take x(t) = 1/(|t| +1) <= 1 ?
so M = 1
$y(t) = \log\left(\frac1{|t+1|+1}\right) = -\log(|t+1|+1) \rightarrow -\infty$
alee
so $|y(t)| \rightarrow \infty$
alee
so limited input that does not produce limited output
im studying this
but I'd like to see how you proceeded
It's the same, just take x(t) any positive function that goes to 0
did you study this by any chance ?
it should be called signal processing / signal theory
btw before i missed a -2
and it was (....)^2
@twin pivot Has your question been resolved?
@twin pivot 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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
Consider an exponential function whose rule is of the form f(x) = acb(x-h) + k, where 0 < c < 1.
What are the possible values of the parameters a and b?
Closed by @soft pewter
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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 help with my geometry work
,rccw
are those two lines parallel?
it does not matter honestly
the 51m and the 68m line
No but for similarity it would
You have three angles that are similar.
That is enough conditions
it already fulfills AA similarity
oh wait I missed the label indicating equal angles
@sturdy grove, hopefully that gives you an idea of where to go.
Use the fact that if two triangles are similar, then the ratio of their sides are equivalent
okay
Is it 36?
I got 36, is that correct
I did 68/51 multiplied by 48/z
oh
Yay
Thank you everyone for your help
.close
Closed by @sturdy 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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
you just have to write out what g(f(x)) is
Closed by @wanton heron
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
GENUINELY what am i doing wrong
i bet its something super stupid
there shouldn't be a boundary at 1
recheck your signs
If you are done with this channel, please mark your problem as solved by typing .close
.close
Closed by @prime tusk
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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 explain the solution? I dont understand the derivations for a > 1, 0 < a < 1
@tulip panther Has your question been resolved?
When a > 1, a^{sin(x)} <= a
When 0 < a < 1, a^{sin(x)} >= a
(when a = 1, a^{sin(x)} = a, obviously)
ah
it took me a while to see it but i do now
why do we select the greater value of x for a > 1 and vice versa for 0 < a < 1
and are there any resources online so i can practice considering cases for exponentials (and maybe logs)
Wdym "the greater value of x"?
so for the case $a > 1$, we say that $a \ge \frac{3 + \sqrt{5}}{2}$, and for $0<a<1$ we select the lower value (the value with the - instead of the +)
keqae
Oh that
how do I explain
I think it's kind of implicit but they're taking sin(x) > 0 because the equation has both sin(x) and -sin(x)
Like it's a^{sin(x)} + a^{-sin(x)} and one of these terms is > 1 while the other is < 1
a^0 = 1 and a^u as a function of u is monotonic, so a^u and a^-u are on either side of the (0,1) point, both horizontally and vertically
So just pick u to be the one on the right, so u > 0, and if a > 1 that gives you a^u > 1
(3+sqrt(5))/2 > 1
On the other hand, if 0 < a < 1, that gives you a^u < 1
(3-sqrt(5))/2 < 1
Just graph it
what do i graph? a^sin(x)?
No we don't really care about sin(x)
It's just there to restrict the exponent to [-1, 1]
Think of the question as a^x + a^-x = 3, but with the added restriction that x must be in [-1, 1]
So graph a^x and play around with a
Maybe graph both a^x and a^-x at the same time, though really you should be able to imagine a^-x as the reflection about the y axis
hmm okay
Also graph y=a so you can visualize when a^x is above or below a
i can definitely see that a = 1 => y = 1 for all x
although trivial
yeah can see that
Sorry I have to go
I made you this: https://www.desmos.com/calculator/3rxz87lm0k
When the vertical green lines show up, that means there's a solution
Should be enough to understand what the question is really about
Good luck
oh alrighty thank you so much
i understand that it works now
i just dont understand how
@tulip panther 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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
Given a circle with center O and diameter CE.
From point C, draw the tangent Cx to the circle with center O (C is the point of tangency).
On ray Cx, take a point A.
From A, draw the tangent AB to the circle with center O (B is the point of tangency, B ≠ C).
Let H be the intersection of OA and BC.
Draw AE, which intersects the circle at point D (D ≠ E).
Prove that HB is the angle bisector of ∠DHE.
I’ve been thinking about it for two hours and still can’t solve it.
Have you made a diagram?
What have you tried?
i made
ofc
ok , wait for 5 mins
@bold flume Has your question been resolved?
Here's a better diagram I made, sorry I had things to do, I'm free now
Also you made me recall the reason I hate Geo
If we show $\angle DHA =\angle OHE$, then we can deduce the given
Alexis_Fx
why DHA = OHE ?
Similar triangles
What conditions are needed for those two triangles to be similar?
Since we need the angles of those triangle
We might want to look for the ratios
It's a good idea to try showing Side-Angle-Side
now we have a new problem
Which sides are proportional to which sides, and which angles are equal to which angles?
Why don't you try first
alr
i will think
but I find your method a bit hard to understand.
My solution is pretty short tbh, take like 5 lines
I feel completely stuck now.
well I can give you a hint: triangle ADH and triangle AOE are similar
oh lmao
are u sure , angle ADC is 90o , angle AOE is not 90o
hi 
gm csp
oh i see
now we have AHD = AEO
um
still hard
can u gimme the next hint
wait , we need to show triangle HDA similar to triangle HOE , dont we?
now , we have angle ADH = angle HOE
the ratios are hard now
ye , showing it is a problem
why is that a problem
triangle ADH and triangle AOE are similar
That should directly deduce AD/DH=OE/OH
what
I thought this couldn’t be deduced directly, because my teacher taught me that it can’t be inferred directly.
This doesn’t relate to the two main triangles we need to prove, because it doesn’t involve OH.
It does
Also, i hope this helps somewhat declutter the drawings,
not directly tho
So can OA be replaced by OH, or what?
Dude no rush, have you tried to relate OE/OH to other ratios
no , i didnt
Then try that out
ACO as a triangle itself doesnt tells us jackshit, right?
its just part of the construction
yeah, but it's important to keep in mind since we are not sure what related and what not
While solving
tbh i havent read much of the convo so im just brainstorming
but AOC and OHC are similar
therefore ABH and BOH also are
then we have AH x HO = BH2
AH x HO = HC2
i tried and saw nothing
okay i found a way to reduce the problem a lot
Both OE=OB=r
we can literally get rid of B
What now
AO/OB=HO/OB=HO/OE
HC has to be a bisector of these lines too
basically we are done
Hmm well that could be an approach
Have you found the sol with that construction
still looking at it, but i think it should be relatively simple from here
I already sent my method above, so ig Imma head out if OP doesn't have any question
im asleep , maybe i will think about this tomorrow
close this ticket then
Using geogebra
.close
Closed by @bold flume
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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 unsure how to complete these questions (the text reads “solve the equations”)
Starting with a)
The correct answer is 6. I got two answers, one of which is 6.18, pretty close but I’m unsure how the correct answer is ONLY 6, given I’m pretty sure the only way to solve is to use the pq formula
Which inherently gives two answers
wait
Yeah, the 16 and -16 cancel each other
What did you do here
I multiplied 1 by x+4
You can't just do that
You have to multiply both sides
That means you also have to multiply x/(x+4) and -16/(x+4)
you have to multiply everything on both sides
Oh, now I’m getting x = 6
Ok
For b)
It seems pretty clear cut to me, but the answer is that it’s not solveable
The sticking point that I could see being in error is multiplying both sides by t-2, but it seems correct to me
you were so close
8 = 4t
that does not imply t = 0.5
everything before that step is correct
Oh, t= 2
yeah
Right, but according to the textbook it should still not be solveable?
indeed
cause you're dividing by t - 2 which would equal 0, in the original equation
actually if you go back to (t - 1)/(t - 2) - 3/(t - 2) = 5
the denominator
Yeah
combine the fractions and (t - 2)/(t - 2) = 5
that's impossible
Ok, so I just did a mistake at the very end, that’s not too bad
Now, for c
I’m unsure how to ensure the denominator is the same across the board given there’s a y^2
Like this
But as there’s a y^2 the denominator is still different
So I am unsure how to rectify this
<@&286206848099549185>
(Pinging due to inactivity)
SHAW!
Hegale!
Mutiply y^2 on both sides
yesz
Ok so using pq it’s either 3 or -2
According to the textbook it’s only -2
However, neither 3 or -2 make sense if you put them into the original equation?
Did I make a mistake in using pq?
Its either -3 or 2 so ye i think you made a mistake
The textbook says the answer is -2? I don’t see any mistake in my working
Aint it supposed to be -1/2
?
You’re right
In pq it’s - x/2
Right I’ve made that mistake before
Ok ok
Now I got 2 or -3
Onto the final part
For d
@unreal scaffold Has your question been resolved?
This is what I got so far
But the answer is -2 according to the textbook so I must’ve made a mistake somewhere, I just don’t know where
Idk
Ok got it
Thanks for the help!
.close
Closed by @pliant shore
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
@stiff lynx
Do you have a maths question?
Does Jai have a maths question?
@uneven token 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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
exercise2: second equation
you know l'hopital?
well I'd love to know how you solved the first thing of exercise 2
yo i gotta go now i have some work
wya
me need help
how do you know this
the exercise says f'(-2)=4
very true
f'(-2) is
ahhh that's what they want alright
try to write the bottom of the expression as the derivative part
yeah
now devide the top AND bottom by x+2
there is no x+2 in the bottom
yes
Need more help or do you got this
but how did u go from this
to this
we devide the numerator and the denominator by x + 2
so on top we have 3 (x + 2) devided by (x + 2) and in the denominator we have (f(x) - 1)/(x+2)
in the numerator, x+2 devided by x + 2 is just 1, so we are left with 3
.close
Closed by @old pilot
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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 re-learning some math and I am really struggling with bounds of polar curves. I think it's because they are drawn in cartesian instead of polar coordinates.
Here is a question which doesn't make much sense to me indentifying the boundaries.
To provide some of my logical-assumptions.
So the function appears to be in Qiv, so it must be bound by 3pi/2 and 2pi because that's outside the bounds of 0< theta < pi
Obviously that's not right.
Doing some math, I set r(theta) to 0 to find points of theta where the radius is 0.
At that point I get solutions that are 0, pi/2 and pi.
I am not entirely sure what is the upper/lower limits of the integral.
Looking at the R area's loop shape and I think that, well the bottom left loop has a 'negative slope/angle' but so does the upper right loop. But none of my theta values represent negative values; as 0 to pi/2 is Qi that's positive values, and pi/2 to pi is Qii which is again positive values but my R is a region with negative values.
Then I read about 'following the loop' method. But that didn't help me either.
Are you sure that pi/2 to pi is in Q2?
At θ=3pi/4, sin(2(3pi/4)) = sin(3pi/2) = -1.
using this unit circle as an example. yes
https://lh3.googleusercontent.com/proxy/o2BQKpBGTtOGBT7zrPRZC1HJWEqqzfOGISEOPxe23hrrpY-XBfMQ9zyfW8fdGAV9IhK5QTJNTohUQ7mhaZtYCdACgpjnb32wlyicetIF40JAOnozyKfS-SGsSvuk
The 2 in 2θ changes the periodicity though.
I understand the point you're making.
in that case the pi/2 to pi would fall into Qiii and qiv which is both negative
Correct.
However ... that is only relavent in suggesting that sin(2θ) is negative. It does not necessarily force the curve into Q3 and Q4.
Imagine an arrow pointing in the direction of θ. Along that arrow, there is a negative and positive direction with respect to the origin. If the radius is negative, then the point will be in the opposite direction of θ.
I am mainly using khan academy to re-learn. I tried using chatgpt but they aren't as helpful without visual assistance. I tried reading a textbook from Stewart - Calculus - Early Transcedentals 6e and they just skip 'bounds' entirely and the problems themselves are in r, theta plane so the bounds are just readable.
I tried looking up youtube videos but they seem not helpful to me.
I am struggling to re-learn this concept.
My brain feels like it's melting.
One moment, let me make a graph that may help out.
here is another example I am doing it. I already 'solved it' and the website is just re-cycling the question. I can also 'feel' that the correct bounds should be 0 to pi because xy is in Qi and Qii but also i know that isn't a good assumption to make translating to r(theta)
i found theta solutions for when radius is 0 at theta = 0, pi, and 2pi
so i think like this
i am making these assumptions based on the region R having a positive slope and then a negative slope
It would be alot simplier if i found a 'formal' guide explaining how to find these bounds but i've tried using 7 different sources and none of them were helpful.
In that graph, the green line is the direction of theta. The distance away from the origin is r(theta).
If r(theta) is negative, the point will go in the opposite direction into the red line.
The whole concept of a negative radius tends to confuse a lot of people.
Still there?
Finding the bounds in polar integrals can be tricky. Even when you have intersecting curves, theta is not always the same for both curves.
i feel like i am going in a feedback loop because i can't grasp the basics
Because in one problem i think i understand the idea but then the next question gets me more confused.
In the second problem
i know radius is zero at theta = 0, pi, 2pi.
So I i think, for what theta value do i have an area R that is above the x-axis.
Well that means, i have positive y values.
But i intuitively equate that, without thinking, that it also means r(theta) must be positive.
But since's sin^2, r(theta) is positive for all theta's then pi to 2pi should also be valid bounds? Obviously not, but i don't grasp it fully.
It just really confusing being given a function a (r, theta) but plotted in (x,y) and then go back and forth making these analytical deductions with a single visualization... it's so confusing because i am using incorrect assumptions.
I know that it looks like the area R is the positive part of the function, so the bounds are probably 0 to pi, but r(theta) is still positive for pi to 2pi bounds using the r(theta) equation.
if the graph was in r, theta coordiantes i wouldn't be struggling at all.
i was watching a youtube video of a slightly more complicated problem, and they made assumptions which i don't understand how they made.
Here it is:
I don't understand how they figured out the shaded region is bound by pi/6 and pi/2 .
I understand mathematically how they found the various points at which radius is 0
But to tell what interval denotes what area makes no sense to me.
Are you trying to find which interval of theta R is?
He is having difficulty understanding how to determine the bounds for regions.
yes my issue is only bounds
The first thing I would do is determine the periodicity of the radius. You can do that by using the identity 2pi/P = B.
For r = 3 cos(3θ), 2pi/P = 3 means that the periodicity is P = 2pi/3.
At that point, barring any external variables, the curve should overlap itself.
So you know that at the bounds r(theta)=0
And to work out which ones you want, you use this, and if r<0 then it's the opposite
but in this question the r(theta) is never 0, so how do you do bounds here...
If r(theta) isn't 0 then it's either always r positive or r negative, and the theta would just be #help-36 message (or flipped if negative)
I can't tell you how to do every question because I have no idea what sort of question they'll be but I think these are the two cases
So in this one it starts at theta=0 and ends at theta=3*pi/2
If it's a loop that doesn't appear to have boundaries, (Like this one but in all quadrants), then the bounds are 0 to 2pi or anything to anything + 2pi
Try making them on desmos https://www.desmos.com/calculator
@sinful compass 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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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 explain how he goes from these two steps
wdym
the negative from -lim moves into the denominator, and lim(h->0) is the same thing as lim(-h -> 0)
it's two separate steps
Closed by @left trail
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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 do not understand example a
@runic phoenix Has your question been resolved?
If b is nonzero then the identity is not in the set
@runic phoenix 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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
🙁
Your channel timed out so you need to repost your question
Just read azyrashacorki's explanation
Identity is a synonym for the 0 vector if that's what was confusing you
@runic phoenix 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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Help pls qs1
Could you perhaps translate this?
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
The population P(t) of a village is given by the rule
P(t) = 6530(3)^0.1t
where t is the number of years that have passed since 2011.
By how many inhabitants did the population of this village increase between 2016 and 2023?
what have you tried
nothing so far this was b) i did a)
but thsi one im having trouble
you are looking for P(2023-2011)-P(2016-2011 )
not quite, t is the number of years since 2011
right mb
how can i make 2 equations
you dont need 2 equations
you need two numbers
the population in the year 2016 and in the year 2023
oh alright
the formula tells you how to compute those
yeah
yes
2016 - 2011 = 5
,calc 6530(3^((0.1)(12)))
Result:
24403.869107068
yes
alr
btw
its 11 310 for 5 years
but what do i do about the decimals
since its peopel
round to greatest integer less than your number
oh so 24 403
24403 for 24403.869107068
alr i see
yes
now i have to subtract ?
yes
np
.close
Closed by @soft pewter
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
But does the Fourier transform of 1 equal infinity?
$\int_{-\infty}^{+\infty} e^{-2\pi iy\xi} dy$
Goofy Joe
Help !!!
@twin pivot Has your question been resolved?
You can use the sine-cosine form instead of exponential
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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! can someone help me with this angle chasing problem my friend sent me
the only idea i have was to reflect D across AC so that AD'BC are cyclic but i dont think thats getting me anywhere..
i might be kinda stupid guys
!status
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
the triangle OBC with that middle intersection point being O is isoceles, to be a little cpt. obvi
since you've worked out that BOC = 6x, then that gives you something to work with
im just going to try and angle chase all of the angles in this diagram
with O as the intersection of BD and AC
The remaining angle of the isosceles triangle will be 180-6x and you try to find <BCA. After finding <BCA, use sum of angles of triangles is 180 theorem in triangle BCD.
im probably stuck somewhere midway
oh, is that it?
ayyy
or you worked out all 3 angles in this triangle
Calculate these angles in order as shown, then you can find the value of x from triangle BCD.
sum of angle in this
Ohh wait...
i mean, <BCA = 180-17x + 3x = 180 - 14x but that doesnt simplify...
you worked out this far, try sum of angles in a triangle in this
you should be able to solve for $x$ with some algebra
1 divided by 0 equals Infinity
or you can do what he said here
Hmm...my idea does not work. We might need some construction
i just used <AOD' = 90 and then sum of angles
Where is O?
Closed by @lime crest
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
Given 2015 distinct positive integers not exceeding 3019. Prove that among these 2015 numbers, there exist a, b, c, d such that a + b + c = d
i will show my work right here
i think maybe i can use this but have no idea how to proceed
:<
,rccw
,rotate 180
it seems like u are a wise guy, pls give me some guidance im so lost 😭
diriclet exercise?
@arctic sand Has your question been resolved?
pls help
!close
.close
Closed by @arctic sand
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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 here im confused a bit
Assuming normal distribution, you are to find the area that satisfies < 98ml and > 105ml
yeah
but
You use your z-table for these
Nope
You find the prob of an individual bottle not fitting the criteria
and multiply by the amount of bottles
but
how do i know what number of bottles are outside the tolerance
wait
shir
omg
dont i just do 1-p(98<x<105)
yea
also its not <= right
oh shit
Since the probability of a single point is 0
ohhh i remember
my teacher did the = in (=)
man 😭 its 9 pm i gotta learn inverse normal distribution and hypothesis tests
i got a big exam tomorrow
For any question of this kind, you work with the logic that the expected proportion of valid/unvalid is always equal to the theorical probability of an individual product being valid or not
And in reality, by the law of big numbers, the more products (bigger sample), the closer you get to that expected proportion
yeah i was wondering like
the mean is the same as 100 ml
The mean is 100ml, yeah
is rhat what u mean
Not really, gimme a sec
okay
When you have any distribution you use to find the probability of an event
Here we have the normal
yeah
and we want to find the probability of a random value being below 98 or above 105
And once you find that prob., if youre asked "how many products are above/below that threshold /aka invalid"
Then you multiply the probability by the amount of products
lets say here we have p% * 10000
And thats how many products you expect to be invalid
ohhhhhhhhhh
yess
ty
Its the same basic idea as coin flipping but with extra steps
ill do this exercise really quick then move on to the next omfg im gonna br fucked
yeah
btw in the example we did its basically "or" right
how do we include that or
@copper roost Has your question been resolved?
Closed by @copper roost
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
Apparently the answers are the 2nd and 3rd
I got the 3rd cause the degree of x in the numerator is 1 higher than the degree of x in the denominator
But for the 2nd I got this
Which isnt 1 higher (I think)
Cause you can divide all terms by x, right?
Or does the 1/x mean I cant?
Or is my method just wrong?
$\sqrt{x^2}=|x|$, not just $x$.
Civil Service Pigeon
So $\frac{\sqrt{x^2+x}}{x}=\sqrt{\frac{x^2+x}{x^2}}$ for $x>0$
Civil Service Pigeon
but not for $x<0$
Civil Service Pigeon
Civil Service Pigeon
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
asymptotically equal to

.close
Closed by @toxic tree
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
looks fine, what's the question?
In the solution they gave how come the absolute values just dissappeared?
when x is near zero, x+1 and 1-x are both positive
so you can remove those abs vals
for the one in the denominator, |x| becomes x for the limit from the + side, and it becomes -x for the limit from the - side
just in case, remember the definition of |x| as a piecewise function
Closed by @toxic tree
Use .reopen if this was a mistake.
yw
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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! is parametrisation if i can describe a geometric object with an amount of variables equal to the dimensions of that object?
yes
okay, i have a followup
more specifically, the number of parameters is actually the degree of freedom of the object
which is formalized to define dimensionality
okay thanks for telling me that, i also have a followup question: if the amount of parameters matches the amount of dimensions, but i change the parameters, but still only use the same amount, is that also a parametrisation?
sry for such a confusing way of phrasing it
or am i just changing coordinate systems
or maybe something else
parametrization is not unique, e.g. changing coordinate system
i'm actually not sure if parametrization is unique within one coordinate system
but my bet is yes silly me it's not
oh true
that is parametrisation
we were discussing whether a parametrisation is unique or not
if you can express your variables in terms of functions of that variable, then it's a parametrization
oh sry ye i didnt follow that
what does it mean for something to be unique
you can only do it one way?
okay this confuses me
because to me it sounds like
"Unique" means that if two elements satisfy the property in question, then those two elements are in fact the same element.
copy pasted straight from reddit lol
i mean i could express a variable as something that depends on 1 variable, or multiple
but i thought i wanted to match the amount of parameters to the dimensions
to verify if it is a parametrisation
so if i have a surface, it an object that can be described in R^2 even if it lives in R^3, so i would want to go from some amount of parameters to 2
for it to be a parametrisation
or did i misunderstand –
it is okay if i did!
my goal is just understanding
i feel like those two things contradict eachother
i don't think this is necessary
i will get an example
damn a guy convinced me of that being how i should think of parametrisation
and i liked it
i feel like i have moved between 3 or 4 definitions and i dont feel closer to understanding it 😦
it's very likely that i'm the one who doesn't understand, i will illustrate one example but i think that's all i'm good for
not too well versed in this
but let's say you have a 5 variable matrice and you notice that there's 2 non leading columns
none leading means? sry language barrier
then we have that the 3 leading variables will be parametrised by the 2 non-leading ones
like uh
it's not the first entry in the row after the matrix has been reduced to row echelon form
wait that might not be a complete description
yeah idk i'll leave this question up to someone else
are they like pivots?
maybe just re post it so people know what they're coming into
pivots are what leading columns come off of
should i be picturing some form of staircade but maybe the steps are uneven
staircase*
or does none leading mean that there is no real triangle to be seen
or anything triangle adjacent
ignore the circles, the 4th and 5th columns are non leading and hence x4 and x5 are non-leading variables
we set them as lambda1 and lambda2
oh i see!
tho i'm probably not hitting your question, repost your original question below since it's been clogged now
hopefully someone else helps
ok
hi! is parametrisation if i can describe a geometric object with an amount of variables equal to the dimensions of that object? im looking for a way to look at it so i can determine what it is, i really havent understood any definition so far or way to think about it.
@latent gazelle Has your question been resolved?
basically is this way of thinking about what is and isnt a parametrisation correct, or does it need more context – like is it not all-encompassing for what a parametrisation is
@latent gazelle Has your question been resolved?
well you can have more than your dimension
but yes it is a continuous map from some open subset of ℝⁿ to your geometric object that you might want to be surjective or additionally differentiable or smooth or whatever
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Could somebody check my answers and answer the questions I wrote down on 3 of the problems
the negative angles are not in the interval
because the interval is 0 < theta < 360
which is just positive
the other answers are correct
This is confusing me why would sec not equal 2/sr of 3
Sec is the radius/y
so where did the square root of 3 go
what is cosine?
the adjacent side right
sine is vertical
sin0 = 0
two ways of remembering it
a 3rd one: sin1 is very low, draw the triangle and see how the sides are oriented
the same idea can be done with sin30, which is also relatively small
@static oak Has your question been resolved?
Forgot to also send the first page and I have one question at the bottom
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
shdnt i consider the kinetic energy provided by Fsintheta too
@vapid haven Has your question been resolved?
!helpers
To ask for mathematics help on this server, please open your own help channel or help thread. See #❓how-to-get-help for instructions.
<@&286206848099549185>
consider work-energy relationship
or Integrate accelereation
you mean integrate work?
you are not given m
The first line...
take m constant
Well you do not 'take' it as constant. It is given to be constant at m for this problem. The mass may not necessarily always be constant
but work energy is better
but if you take as m
n would be in terms of m
Read what I wrote
in 1/2 mv^2 m cancels out
i asked my doubt
wont Fsintheta also contribute to KE.
Do you know the WE theorem?
yuh
how/
Okay for your question, the vertical component is adjusted in the normal reaction with the surface
Try to think about this physically, things dont levitate like that
||int vdv = 1/m int
you get v^2/2, multiply m m cancels out||
And in the context of the WE theorem, no work is done in the vertical direction @vapid haven so no K contribution
Sorry Intergalactic
alg
why
bruh how.
For reasons I explained above
linear motion
is given in q?
yes
👍
80% phy can be solved by energy conserv in jee
It shouldve still said F < mg. Youre right
ill keep that in mind fo sho.
i hope i finish WPE by today ngl
they gv linear motion so ig we assume, but thanks
what is WPE/
work power energy, short form i use.
cannot be directly you have given forward acceleration
true.
like it can be 2D if Fsintheta> mg
edit:mb
Wait nvm

If you are done with this channel, please mark your problem as solved by typing .close
Closed by @vapid haven
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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 help
i found this answer key online
but i dont get how they got yxy/2 = 1
how do they know that the height of ABE and base of ABE is the same
How do we know which square is smaller
DEFG is smaller because Pythagoras
👍
that relies on showing triangles ABH and ADE are congruent
if you do a bit of angle-chasing
say angle BAH = x
then angle EAD = 90 - x
so angle ADE = ...
or alternatively RHS congruence might be easier if you know it
ABH and AED are congruent => AE=HB
what does that give you
AE and BH
because AE and BH are both the shorter sides of the triangles
It gives , AE =BH , then we know that
(BH ×AE)/2 = 1, so AE =√2
.
@sand escarp 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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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 clarify what i've wrote thanks
again same
what did you not understand ?
@rain sentinel Has your question been resolved?
the reciporcal bit
yh]
so what you have is 1/a *(a^g/Rlamda)
then just apply exponent law
a^b/a^c = a^(b-c)
@rain sentinel Has your question been resolved?
Closed by @rain sentinel
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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 prof just introduced my class to complex numbers n said there's 3 ways to represent them:
Trigonometric form
Polar form
Exponential form
The class ended before she could explain any of them
Can someone explain em to me
Just look for some materials I'd say, it's been already explained better than we are able to write down here I guess, there are plenty (videos, websites, tutorials etc.)
Actually yeah this
But
Trigonometric and Polar are the same
I think
And then, if you get stuck somewhere, come back and ask
@merry lodge Has your question been resolved?
Closed by @merry lodge
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
How do I do this? My main issue is that I don't know if I'm supposed to add al lthe steel parts together before doing the equation or not. But I also still just don't know how to do the actual question itself. I get the modular ratio, but other than that, I don't.
@sterile willow Has your question been resolved?
Now it would be useful to know the position of the neutral axis
then you need to calculate the moments of inertia and the equivalent moment
How do I do that?
start with the cross-sectional areas of the individual components (you can divide the steel channel into 3 rectangles)
DO I need to find the area of the transformed areas?
I basically looked throughout many websites on how to do this question, but I don't understand this part
If you're using such a method - yes (and I see you do, because you told us about the modular ratio)
Okai, would it be right to add the widths up together and then multiply with n? or to do all of those separately
I wouldn't calculate transformed dimensions, rather transformed areas and then transformed second moments of area
Separately, at the end you can apply your modular ratio (n)
This is why I suggested to split it into components
So 375 x 16.667 +12x 16.667 (x2)
??
n should be applied to areas, not dimensions
and only to the non-reference material (wood)
I'm so sorry, I really don't understand anything-
Okay, do you understand why we need position of the neutral axis to calculate the stress?
Not really
Or do you know the formula for the stress (i.e. flexure formula)?
this?
I think the furthest point from the neutral axis
Yes and this is why you have to know its position
Yeah, you'll need it
Ok then, the later parts make more sense to me now, this is the only part where I'm HIGHLY confused