#help-27
1 messages · Page 341 of 1
@wheat umbra Has your question been resolved?
No.
@wheat umbra Has your question been resolved?
@wheat umbra Has your question been resolved?
<@&286206848099549185>
i had to endure this in class last semester
but tbh i don’t get it
@wheat umbra Has your question been resolved?
https://www.youtube.com/watch?v=L1gd5PrTcUY This seems not too bad too
Recorded Friday, February 18.
A second course in linear algebra covering vector spaces and matrix decompositions taught by Dr. Anthony Bosman.
Full Course:
https://www.youtube.com/playlist?list=PLOROtRhtegr4HyXIIHKHketOm2k3JWSpK
The lectures closely follow 'Advanced Linear and Matrix Algebra' by Johnston:
http://www.njohnston.ca/publications/...
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.
$\lim_{z\to \pi n} (z-\pi n) \left[\frac{\cos(z)}{\sin(z)} - \frac{1}{z}\right]$
jandro0103
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
can i do this ?
also : the limit on the right approach 0
can i just evaluate the limit on the left side by using de l'Hospital ?
i mean (if i apply the limit on the right side) :
$\lim_{z\to \pi n} (z-\pi n) \frac{\cos(z)}{\sin(z)} - 0$
jandro0103
pls help
isn't (z- pi*n) just 0, so the ans is 0?
right
.
idk
<@&286206848099549185>
remember that sin(z) = (-1)^n sin(z - pin)
so then recall sin(t)/t when t-> 0
im asking if i can do this
you're asking whether you can do lim(f+g) = lim(f) + lim(g)
if you know one of f or g converges
anyway thanks for the tips
i know that lim(g) is approaching 0
yes
so you're allowed
because if f diverges
then f+g diverges too
and if f converges
then f+g converges too
ok so when i cant do this ?
if you have convergence of neither f nor g
so if both diverges?
okok
so this is correct ?
yes
that i writed -0
oh yes
also did a little oopsie
forgot a (-1)^n
anyways
that's about it
but cant i just apply the l'hospital since its 0/0 ?
i mean when i get to this point
$\lim_{z\to \pi n} (z-\pi n) \frac{\cos(z)}{\sin(z)}$
jandro0103
i can apply the l'hospital
how would you apply it here then
with function is your "numerator"
and which function is your "denominator"
(there's also easier than l'hôpital)
$\lim_{z\to \pi n} \frac{(z-\pi n) \cos(z)}{\sin(z)} = 0/0$
jandro0103
that's gonna cause you unnecessarily problems imo
why?
don't you know the limit of sin(x)/x?
so its (-1)^n / (-1)^n = 1
when x -> 0
isnt this enough ?
(z-pin)(sin(z))
just to show we make a lot of mistakes
with unnecessary computations
sorry
(-1)^n / (-1)^n
yes that seems easier
ok
$\lim_{z\to \pi n} \cos(z)\frac{(z-\pi n)}{\sin(z)} = \lim_{t\to 0} (-1)^n\cos(t)\frac{t}{(-1)^n\sin(t)} = 1$
rafilou is not not born in 2003
mm
so you sub t = z - pi n?
oh no
yeah
ok i got here
jandro0103
mm now ?
ok
so we use lim(f*g) = lim f x lim g ?
@sick valley 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.
Given a n x n array with unique entries, with an equivalence relation of a possible rotation by 90k and then a possible reflection across a line that is 45k (k is any natural), how many, and what, are the equivalence classes
i solved this problem for 2x2, using differences in diagonal entries, but the general case probably needs linear algebra or smth
no idea where to start with the general solution
most likely needs a case for even and odd n, as odd n results in n times more classes just due to the center
another wording of the question is, how many different initial states would you need if you needed to get all n! possibilities given the transformations
and how would you obtain one of every initial state
If I understand your question correctly I believe if you are given the location of the 4 corners of your array you can figure out the position of all the other elements. Thus, considering 2x2 should be enough
how come
oh i figured it out, you only have to consider quadrant amount and n mod2
ty
.close
.close
Closed by @lavish patio
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.
wouldnt tan pi/6 be sqrt3?
no
1/sqrt(3)
pi/6 is 30°
Try to use the 30-60-90 triangle I mentioned to you in the previous help channel
Again don't memorise those
sure
Yes!! One way is to memorize the triangles, the other is to just use sin / cos to find tan
remember the coordinates are (cos, sin) in that order
eh.
You can but generally we rationalize the denominator
yeah like you shouldn't treat the presence of roots in denom as something inherently illegal lol
sorry I have another question
how do u graoh this?
i find graphing very confusing
im guessing its based off of the angle so it would probably be d
but how can i be so sure? (The answer was d im just checking if there is something else I can look at incase)
y = sqrt(3)*x goes thru the origin (as does any line of the form theta=something)
a and c are out on that alone
and it's got positive slope greater than 1
@zenith viper Has your question been resolved?
Closed by @zenith viper
Use .reopen if this was a mistake.
.reopen
✅
how is this done?
how have you been doing polar-to-rectangular conversions normally?
idk i usually find the polar coordinates
I recommend visualizing this
Then it will be easy to figure out
so i should graph it?
you know how an angle corresponds to a point on the unit circle?
Yeah sure
sort of
you take this standard correspondence with your given angle, then scale both coordinates by the given radius
the words are kinda confusing sorry
i.e. an angle theta corresponds to the point (cos theta, sin theta)
then scale everything by the radius
Just make the relevant sketch, it’ll be easy to understand then
the sketch makes more sense visually
this might help
oh ill try that
forgot the right angle but still the idea is there
wait 2pi/3 is r or y for me?
2pi/3 is the theta polar coords are always (r,theta)
doesn't matter it represent something differently
no
polar coord use a distance (radius) and an angle to show position
where cartesian only show position
the point given is in polar form (r,theta) and you want to convert to rectangular (cartesian)
you can use this
ofc don't forget the rectangular is represented as (x,y)
so i find y using 4sin theta and x using rcos theta?
then the answer i get for those is the coordinates for the rectangular
it'll be -9sin(2pi/3)
for y
yep
or do we find that some other way?
ok thanks
sorry is it ok if u kinda show how ud solve it to end up with a fraction? when i use a calculator i get a decimal
and im pretty sure the question is looking for fractions
are you familiar with reference angles and special angles ?
yes
what is the reference angle of 2pi/3 ?
120?
still not the reference angle (that's just the same angle in degrees)
oh sorry i meant the angle was 240
so 4pi/3
i accidentally subtracted 360 from 240 after getting it as an answer when subtracting 120
the reference angle is (pi-2pi/3)=pi/3
but you still need to consider quadrants
the angle is in quadrant to (so the cosine value should be negative and the sine will be positive)
-9cos(2pi/3)=((-1)(-9)cos(pi/3),-9sin(pi/3))
oh ok is there a step after that?
because in the answer key it says that the answer is:
ofc you need to find the values of sin(pi/3) and cos(pi/3)
pi/3=60deg
oh i got it im so dumb i forgot u can get sin and cos from the coordinates on the circle
@zenith viper 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.
not sure how to simplify it
factor out the 1/3 and it's just in form of af(x)
integral of af(x) is aF(x)
Closed by @tawdry harbor
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 happens to f(x), f'(x) as x approaches infinity
f'(x) becomes a value bw 0 and 1
f(x) diverges to infinity
ohhhh
I see so after some point f(x)>f'(x)
yeah
yea
Closed by @remote sun
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
How do I solve for perimeter of region
try connecting the transition points between the segments and the circular arcs to the centers
in order to figure out the measures of the circular arcs
so then each arc would be 60?
not quite
or 120
why would it have to be 360/3
idk if this is right but each circle is 360
didnt really indertsnad that
It's more that, if you connect the centres to each other, you get an equalateral triangle
oh
^
That angles around a point sum to 360 degrees?
i said that wrong
i knew that
but i didnt think to solve it like he did
Ah
This is less of something that is "taught"
This is general problem-solving skills
In this case, explicitly:
- if we connect the centres, since they have the same radii, we get an equilateral, so its internal angles are all 60 degrees
- if we connect the centres to the point where the "perimeter" diverges into a straight line by leaving the curve of the circles, then these lines are connecting to tangents of the circles
- this gives us rectangles drawn connected to the main equilateral triangle
- so the other blue angles are each 90 degrees
You can sorta see that you do know these individually, but the main trick is to force it out of the question and convince yourself (and a reader - in this case just drawing the lines and right-angles will probs be enough) that what information you're drawing out is logical
And then bringing those things together
Closed by @junior jewel
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.
this is so confusing
Im guessing he wants you to fjnd the hypotenuse that the 2 distances of the trains make
first find how far away train A is at 11 am and how far away train B is at 10 am
@somber garnet Has your question been resolved?
Yeah you can find the distance of train A at 11 am and the distance of train B at 10 am and then try to find the wanted time from there
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
how
can someone help
you know the time and you know the speed
thus you can find distance
like how much they traveled in 1 hour?
how do i find B's distance?
yes
it traveled for 1 hour at 45 km/h
towards the station right
yes but that doesn't matter
well it does, but not for the distance
it was at some point an hour before arriving to the station
it's the same way you did it for train A
then the hypotenuse?
not sure what you mean by "the hypothenuse" so can't say if it's correct or not
rn you are finding the "boundary values"
is this a calculus or no calculus question
calculus
great
what are they btw
as in what did you get
45 for a 60 for b
correct
now let's consider what's happening at some time t
how far away is A from the station at time t?
can we let x represent some distance
(we can let t be in hours)
why not
nvm
i thoght you said
we cant
mbbb
okay yea
ohhhhhhhhh wait
so we can rewrite the distance at time t
using v = d/t
?
yes
what did you get
for this
how far away from the station is B at time t?
at t=1 hour, how far away is B from the station?
yes precisely
ohh so we want their position relative to station
yes
it would be helpful to draw a little diagram to help visualize this
great
do we find the hypotenuse now lol
yes
omg
you find its length in terms of those two equations
hint if needed: ||distance between two points formula||
i will
what do you get for c?
no worries
we need deirvaive riht
after you get the expression yea
uhhhhhhhhhhhhhhh
what's up
OMG
I've done that mistake SO many times
mbbb
i knowwww 😭😭
the answer is gonna be nice
huhhh
wait actually on line 2 aswell
,w expand (45-45t^2)^2
ye
okay :(
could i get some help when you guys are done?
no shame in that – simply sparing you the misery of having to redo a question 5 times from scratch :)
take a look in #❓how-to-get-help
ok, sorry
show
no two squares
you got this broski
yessir
that's your final answer
4th time was the charm indeed
good job!
i have an optimization test tmr, do you have any tips cuz i feel like with optimization there's way too many different types of problems to study
🥹
it's allll about getting the model right
cuz after that it's just derivatives
so try to use both fornulas and common sense
plug in values to test your model
and you want everything to be in consistent units and (most likely in your case) dependent on exactly one variable
the question asks to find the time, so i figured using t will be helpful
the only issue is that it's not always like that, for example of they asked to find the least distance between trains you would still pick time to be the variable
that's because time is consistent between both trains: their velocities and distances are completely unrelated
okayy
if you tried picking distances as your variables, you'd either get stuck with two variables, or eventually stumble upon what we did here anyway
yea omg 😭
i thought i reacted to this lol but my internal reaction was like "that's just not gonna work"
you have like 3 different distances
distsnce between trains and the station, distance between the trains themselves
you can't pick one x
ohhhhhhhhhhhhhhh
but! all of those depend on time
and they have the same time?
yes
oh okay
they all depend on the same time variable
which is why we use time
so yeah i think that's about it i can give advice-wise
I'll probably go to bed now so i think you'll end up talking to someone else
are you from the US?
nope im from canada
okayy sleep well
aha i see
🙇
7 hour difference damn
oh for uni?
yes
well if that's it for now, feel free to type ".close"
Closed by @somber garnet
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
i need help knowing which trig function to use for which right triangle scenario.
for example:
in the first one, i am given the opposite angle and hypotenuse. this means i use sin.
for triangles #2 and #6, they are the opposite angle & opposite side and adjacent angle & adjacent side. how do i know what function to use for these?
and am i getting any others wrong?
please ping when responding :)
there are no trig functions for opp/opp
that is just 1
we are related ratios of triangle's sides to the angles
they either need to give u two sides (means u r likely finding an angle) or one side and one angle to find the other sides
what function would i use for triangle #2 then? since they're both opposite, there's no function that would work
@royal grail Has your question been resolved?
whatever i'll try later
Closed by @royal grail
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
!help
To ask for mathematics help on this server, please open your own help channel or help thread. See #❓how-to-get-help for instructions.
Try partial fractions and write it as a telescoping sum
Closed by @tough vigil
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 got my answers but how do i graph it?
horiz tan at (2,-1)
vert tab (1,0)
d^2 y/dx^2 = (-2t+4)/(9t^5)
on paper or with a computer/calculator?
paper
make a chart, t|x|y
for t = -1, x = 0, y = 3
and so on, for enough values of t that you get a curve
Closed by @placid trout
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’m double integrals
I don’t know how to horizontal strips for this example
I feel like I have to split it up but I’m not sure
@hybrid maple 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.
This just confused the hell out of me what happened
The y= 3+3.5lamda to z = -1 - 4 lamba also does not make sense to me
oh wait
Why did they pick x to be the lambda?
You can pick any of the three. x, y, or z. x is just conventional I think
one of the unknowns gotta become a parameter
there's no sacred meaning to picking x specifically for the role
Oh ok and I get why the x in the directional is 1 but why is the x in the positional vector 0? is it always zero when the unknown is the lambda?
x = 0 + λ
Closed by @unreal falcon
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Can someone help me with this
,rccw
For the area of shaded region which is the triangle
the area is base times height over two
what is the base and height?
I tried to find the base QS using pythogaras theorem but I don’t think i did it correctly since the answer is diff
you know the height doesn't have to be inside the triangle
But i thought h is supposed to be in the middle of triangle
Oh
if you are not convinced, mirror it over the base
it's a parallelogram
which is also base times height
not really mirror but if you add another triangle it makes a parallelogram
area if parallelogram is bh
so the triangle is 1/2 bh
and if you arent convinced that a parallelograms area is bh then i also have something to show you
Closed by @barren gulch
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Could someone help me understand what did they just did
Which step did u not understand
The one that I have marked
How top red went to bottom red
oh they used the half angle formula
wait a sec
They used this formula
I dont remember the derivation tho
Yea
u mean 1 - cos^2 = sin^2?
yea
Thank you!
np
.close
Closed by @night cypress
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.
@steady marsh every 4th Y means literally if you number the Ys that occur with indices, then the ones numbered 4, 8, 12, etc are guaranteed Xs? Or does it mean that if you have a string of 3 Ys in a row the next one is guaranteed to be an X?
you are asking for P(X) but clearly it depends on which Y you talk about because of the every 4th Y thing
so are you really asking what is the P(X, n) where n is the number of trials?
each trial here will have a 4% to be Y and of those 25% will be X, and every 4th Y will be X as well
so the probability X occurs is a function of how many trials are done
Maybe the value of the number of X/n as n->inf?
i dont think that's what's stumping you because i dont think you've precisely asked your question
This sounds like a gacha system.
is this what you're looking for
100 in particular?
And I'm guessing you want to know the total occurrence rate of X per pull
As the number of pulls get large
this is not good because each pull has a different probability
you can ask of its limiting probability yes but is that what you're looking for
you need to be clear
any finite trial will not be exactly this limiting probability, but will asymptotically approach it
(especially because it will take a lot of pulls to reach the limiting probability, so it's probably only relevant to whales rather than f2players)
well okay in this case we can probably just use the limiting probability
i think given the numbers thousands of trial are sufficiently large in magnitude?
i would say tho
if you arent good at probability you can simulate this
it will do a great job and not be too difficult
it's a good skill to be able to write simple scripts like this!
So every time you pull an X the counter is reset, so we have
X
YX
YYX
YYYX
Each of these we can label with a probability of appearing.
X = 25%
YX = (75%)(25%)
YYX = (75%)^2 (25%)
YYYX = (75%)^3
We can then label each string with the proportion of Xs
X = 1
YX = 1/2
YYX = 1/3
YYYX = 1/4
And finally perform a weighted average
1 * 0.25 + 1/2 * 0.75 * 0.25 + 1/3 * 0.75^2 * 0.25 + 1/4 * 0.75^3
,w 1 * 0.25 + 1/2 * 0.75 * 0.25 + 1/3 * 0.75^2 * 0.25 + 1/4 * 0.75^3
A little bit under half
this is the non-math perspective on conditional probabilities lol
but i really like it for explanatory purposes
It's only ≈ 0.5 so it's slightly less than 2% but yes
there's a similar mechanic in world of warcraft actually
it's a sort of badluck protection
And Fire Emblem Heroes
everytime X fails the occur when Y happens, the probability that X happens when Y happens increases until 100%
Actually, FEH has 3 layers of bad luck protection
so here it stays at a constant 25% until the 3rd fail
Which makes calculating probabilities obnoxious as hell lol
the mechanic im describing goes the first fail makes the next one go from 50% to 70% then to 90% then 100%
they just make the odds hard as hell to actually calculate haha
that we can calculate :p
that's what probability is for
we can quantify exactly what the variance will be
I had a streak of luck so bad I went full tilt and made an old spreadsheet where I kept track of my pulls, to verify that the odds were more or less the same as advertised. And keeping track of the probability state was maddening lol
Which, I'm F2P, so I don't even have skin in the game
ive just realised that your wording of variance is not what i was thinking
the % are deterministic by number of trials it's not random
Exponential distributions have a very long tail, but have probability mass concentrated near the start
So it will probably take thousands of pulls to approach the limit
Yes
i mean given n trials, E[the number of appearances of X / n] is a deterministic number
for n trials, the expected number of appearances of X is not random, so the % at each trial value is deterministic
it's a sequence of % that approaches the 2% value
uh let's see, this seems really complicated 😭
P(X = 0, 1) = 0.96 + 0.04 * 0.75 = 99%
P(X = 1, 1) = 0.04 * 0.25 = 1%
P(X = 0, 2) = 0.96 * 0.96 + 0.96 * 0.04 * 0.75 + 0.04 * 0.75 * 0.96 + 0.04 * 0.75 * 0.04 * 0.75= 98.01%
P(X = 1, 2) = 0.96 * 0.04 * 0.25 + 0.04 * 0.25 * 0.96 + 0.04 * 0.75 * 0.04 * 0.25 + 0.04 * 0.25 * 0.04 * 0.75= 1.98%
P(X = 2, 2) = 0.04 * 0.25 * 0.04 * 0.25 = 0.1%
so this P(X = 1, 2) means the probability that with 2 trials, X shows up exactly once
ideally we have some formula for P(X=k, n)
because then E[X]/n is just 1/n sum k=0 to n of kP(X=k, n)
$\mathbb E[X, n] = \sum_{k=0}^n kP(X=k, n)$
frosst
that's the formula for the expected number of X occurences in n trials
but idk if P(X=k, n) has a nice closed form
no yeah i know what you mean
you're looking for |E[X, n]/n - 2%|
how far is this exact value from the limiting value for each n
but the problem is i cant think of an easy way to find E[X, n]
it's an interesting question for sure
Closed by @steady marsh
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
I need help with 31 if anyone knows how to do this
what have you tried so far?
Do you know how this would be represented?
Then plug the resulting output into f.
Huh?
whats the input
You tell me. We can start with part a.
Yes.
so 6(3x+7)
what's your understanding of composite functions?
nothing
This algebra video tutorial provides a basic introduction into composite functions. it explains how to evaluate composite functions. This video contains a few examples and practice problems.
Algebra Review: https://www.youtube.com/watch?v=i6sbjtJjJ-A
Join My Newsletter:
https://bit.ly/4jUXp6M
Func...
how about you watch this
and then see if that helps with your question
Do you know what g(6) represents?
This algebra video tutorial provides a basic introduction into functions. It contains plenty of examples and multiple-choice practice problems as well as free response problems.
Functions - Free Formula Sheet: https://www.video-tutor.net/precalculus-formula-sheets.html
Functions - Video Lessons:
https://www.video-tutor.net/functions.html
...
id recommend watching the videos so you can see how much you understand and so we can help clarify content
It represents the value of x that you’re going to subsitute for g.
Hence why g(x)=3x+7.
can you show me the steps its alot easier for me to learn that way
Okay.
So we have g(x)=3x+7.
g(6)=3(6)+7.
Whatever you see inside the parentheses, you replace the x for it.
Does that make sense?
The function g(x) is basically saying, you give me x and I give you 3x+7
yes
Okay. Try to apply the principle, then.
Yes.
ok so for B
its different
and idk where to plug in 125
is it
log 5 125 =3x+7
that doesnt make sense
Okay.
The one on the outside is applied last.
You apply the innermost one first.
Does that make sense?
@twilit scroll Has your question been resolved?
Closed by @twilit scroll
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
i need help with a geometry task:
there is a rhombus ABCD with an acute angle a. A belongs to a line that divides the angle a by a ratio of 1:3 and |CD| by a ratio of 2:3.
prove that cosa = 1/8
so i ended up with the last equation and earlier i decided to do something like cos(3*1/4a) = cos(3b) but it didnt really work and it made things a lot messier
@pallid stream Has your question been resolved?
@pallid stream Has your question been resolved?
@pallid stream Has your question been resolved?
@pallid stream Has your question been resolved?
<@&286206848099549185>
@pallid stream Has your question been resolved?
Have u solve it?
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.
Hey, so this is a semi-mathematical, semi-programmatic question I have. I am trying to implement an algorithm that computes the integer square root of a number. Meaning, for a non-negative integer $x$, the largest integer $r$ that satisfies the inequality [
r \2 r \le x
]
There are several algorithms one could use, but my question is to gain a better intuition on the following iterative, numerical method:
\begin{itemize}
\item Start with a guess $r = x$
\item Repeat: [
r = \lfloor\4{r +\lfloor\4xr\rfloor}2\rfloor
]
\item Stop when $r$ stabilises.
\end{itemize}
I can't really understand the mathematical intuition behind why the above should eventually converge. Could I gain some insight on this?
Aero ݁˖ ❀ ⋆。˚
if r is bigger than the sqrt, then x/r is smaller
and you are taking the average of them
so you get put somewhere in the middle
and then you repeat
so intuitively the numbers r and x/r get closer and closer together
and always one bigger than sqrt, the other smaller
(if you didnt round then this would converge to the actual sqrt)
ahh that makes sense now
If your guess r is too big, then x/r is too small
If r is too small, then x / r is too big
thanks
.close
Closed by @sand quarry
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
is there any formula to find the sides of a polygon
i remember studying something liek that in class but cant recall
length of sides or number of side
and with what given info
calculate number of sides @stuck vortex
given?
angle
what angle
of?
strange
as in all interior angles are 156 degrees?
no polygon has 156 degrees sum of internal angles 💀
as in this is a regular polygon?
supposedly not what they mean
oh
The diagram shows part of a regular polyugon
The interior angle of the polygon is 132 degree larger than the exterioor angle
Calculate the number of sides of this polygon
hmmm so all them are 156 degrees
the sum of the exterior angles is the constant 360°
and getting the number of those will get you the number of sides
24 + 132
we get 156 degree as intereio angle
i think n * 156 = (n-2) * 180 something like this maybe
i.e.
(number of side/interior/exterior angles)*(your exterior angle x) = 360
i get 15 from this hmmm
since all the sides are 156, the sum should be n * 156 as there are obviously n vertices then just apply the angle formula...
hmmm
i swear tehre was a formula to find the no of side
yes
BrutalCandor
try applying that
Closed by @stuck vortex
Use .reopen if this was a mistake.
There's another that uses the exterior angle which is more efficient
which saves you a few lines of work
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 anybody help me with z tables?
I don't understand why the solution in this case is Z=+/- 1.96
Cause our critical z value is -2.12, and our alpha/2 is 0.025
So to me, our Z value should be 0.1357 to like 0.0951
you need a wider z table
-1.96 is not shown here
Yeah, it's not shown anywhere, but given my critical z value and alpha, it shouldn't be greater than one, right?
This is what I'm given
I found the Z-test and the alpha values
Z_test is -2.12 and alpha/2 is 0.025
So I should get a value that's in the region of 0.0132 and 0.017, right?
I genuinely don't understand where they get their 1.96 from
the critical z value and alpha values you found are from the data. it has to be measured against the significance level alpha = 0.05 to see if you reject or do not reject the null hypothesis.
I think I understand that part, I just don't understand where they got their 1.96 value from at all cause it's in no place in the Z table except for the values go that high for the critical z values
.
I've looked everywhere online and I can't reverse engineer this.
Ok, could you show me an example?
Cause here's the thing
GIVEN that critical z value (-2.12), that should be my first column, furthest to the left, right?
And GIVEN that alpha is 0.05, that would put me at like ROUGHLY some value between 0.012 or something
But that's a whole column??
I'm fonfused
What's a whole column
Like z could be anything in that column
Nope. Should be 1.96
You're saying all I have is 0.05
Cause to me, my critical z values was this column...
Yea you're not reading z tables correctly
So how do I read it correctly? I get that like this is an area under the curve
And the area under the curve can't be more than one
So that's why I'm so confused about it being 1.96
And I looked online and everything's about how to find the area
Like I'm not given a percentage to find the critical z value, I thought that was this column
Is the z-score my alpha?
Could you just walk through this problem with me? Cause the link you sent me is the same thing as every other tutorial
I would need the alpha and the percentage to find the z value, but I thought that was my -2.12
@supple knot sorry to bother you, I just seriously don't find any relevance in the tutorial you sent me. Is there any way you could walk me through one problem?
You have to read the z table correctly first
On the column under z, -3.4 is just the first part
Each column afterwards corresponds to the next decimal place
-3.40,-3.41,..., -3.49
Are the z values for the first row
Then the entries in the table are the area under the normal distribution to the left of that z value
The next decimal place of what? My z value?
Yes
Hence
Stare at that until it makes sense
Ok, so my z value is -2.12
My alpha is the first row, right?
So if I go to -2.1
The ROW of -2.1
And I go to the COLUMN of my alpha, which is 0.05
It unsurprisingly does not give me -1.96
Or positive 1.96
No
There is no column of alpha
alpha is the value in the table
You're saying that0.5987 is my area?
Yes
God damn that took way too long to get an answer for. I looked literally everywhere for that information
Ok
This z table tells you the value (area under normal distribution) left of z=0.25 is 0.5987
So in my case we're look for the ROW -2.1, and the alpha 0.05
No
alpha = 0.05 is a value in the table, not the first column or row header
Find z=-1.9
Then move to the right until 0.06
Tell me that alpha value
So I don't have the table going far enough to the right
Cause there is no 0.05 in this row
.
I thought my critical z value was -2.12? Is the first row the critical z values?
Somebody should have put axes on this bitch
So somehow I was magically supposed to know that my answer would be -1.96
So ALL I'm given is my alha, that makes sense
Since this is a two sided test, alpha = 0.05 is split into area to the right of 1.96 + area left of -1.96
But then what are the columns? What are those headers?
0.05/2 = ?
0.025
What's the value in the table at -1.96
I explained that here
#help-27 message
.
.
.
This is explaining the first column, I'm talking about the header of each column, meaning the first row
With like the 0.00 and 0.01 and so on
Yes keep reading
You're a saint, riemann thank you so much for helping me out. I'm instantly much more relieved cause I couldn't find this information ANYWHERE
So it's just the decimal place of the alpha value?
No
Do you see this list
And this table as an example
Yes but it didn't make any sense
0.05 is the 0.05 in 0.25
You need to understand these things before trying to jump ahead
Oh, so that's my alpha values and my row x column entries are my alpha/2?
If you don't say you don't understand and you jump ahead, that signals you're either not paying attention or you understand what I wrote
I paid attention and didnt' understand
If I could have understood immediately, I would have
Then don't jump ahead
Did you understand this