#help-39
1 messages · Page 256 of 1
Not sure what you mean by real life meaning, but basically, when we imagine expanding
(x+y+z)^n, its like doing (x+y+z)(x+y+z)(x+y+z)... with n factors. We can take either x, y or z from each of those factors, so each resulting term will look like x^a * y^b * z^c
There are exactly n factors, so that means that a + b + c has to be n. So counting the terms is the same thing as counting non-negative integers a,b,c with a + b + c = n
and counting a, b, c with a + b + c = n can be done with stars and bars
Okay if i changed in the equation (xy+x^2y^2+y^3)
so like (xy+x^2y^2+y^3)^n?
now this is more interesting
im not even sure if there is some way to do this that's better than expanding it
for this specific one, we could prolly find some formula
oh, you actually did
There was a formula which tells coefficient of specific terms
Can we use it here for see different powers?
for counting total terme
possibly, idrk, sorry. I'll also have to go soon, ill try to think about this later and let u know if i find out anything. You can keep this open in case someone else wanted to try and tackle this
Here is what i got so far: each term will look like (xy)^a * ((xy)^2)^b * (y^3)^c with a + b + c = n, the only issue is that this wont always produce unique terms. Simplifying, we get
x^(a + 2b) * y^(a + 2b + 3c). Now we when will it not be unique and maybe we would be lucky enough to get a formula for it, and then we could subtract it from stars and bars. Unfortunately, i dont really have the time to try this atm
Thanks for giving me idea
@fading ledge Has your question been resolved?
Closed by @fading ledge
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 formula for the total number of terms in the expansion of [(x+y+z)^n] comes from the stars and bars combinatorial method, which counts the ways of distributing [n] identical items into 3 groups (the powers of [x], [y], and [z]), where each group can have from 0 up to [n] items (i.e., each variable's exponent ranges from 0 to [n]) ��.Explanation Using Stars and BarsImagine you have [n] stars to place into 3 bins, each bin representing one variable ([x], [y], [z]), where each bin's count gives the exponent for that variable in a term. To divide the stars among bins, we use 2 bars to separate the stars into 3 segments (so the configuration [||] means [x^1y^0z^{n-1}]). The number of ways to arrange these [n] stars and 2 bars is the number of terms in the expansion.Mathematically, the total number of terms is:Each term in the expansion corresponds to a non-negative integer solution to [a+b+c=n], representing the exponents in a term [x^a y^b z^c] ��.ApplicationFor [(x+y+z)^4], number of terms:There are 15 unique terms, such as [x^4, x^3y, x^2y^2, xyz^2], etc. ��.Stars and Bars VisualThink of the stars as units to assign and the bars as dividers. For three variables:Place [n] stars in a row.Insert 2 bars to split them into three groups (one for each variable).The arrangement of stars and bars tells you the exponents for each variable in every term ��.This explains how combinatorics links to the expansion formula for multinomials, using the stars and bars method.
Source?
ChatGPT?
no, thats something else
hmm
ChatGPT + ME
Yeah, seems like you didnt even remove the weird symbols and weird formatting
!nogpt
Please do not trust ChatGPT or similar AI tools for mathematical tasks, as they often generate output which "sounds correct" but has numerous factual or logical errors. Use of these AI tools to answer other people's help questions is strictly against server rules (see #rules).
dont use AI generated content for helping others, if you need AI to generate the answer, you might not be the right person to answer the given question. AI can be wrong often
and this part has been solved btw, the 2nd part that wasnt yet solved is
(x^2y^2 + xy + y^3)^n
.solved (popking's not here)
Closed by @latent quail
Use .reopen if this was a mistake.
Of course, why bothering? 
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.
sorta stuck
I attempted it but used a bunch of assumptions to get root 19
which I highly doubt is correct
labelled graph if that makes it easier
k what your approach?
umm like I have found a way
🥴
lol like how you got root 19
what's the answer?
damn
is it that bad
I can give a hint
please do
like see the triangle IAD draw the a perpendicular to AD from I
it bisect AD at rt angle
u can find it's length
like find the length of perpendicular bisector from I to AD
by pythagrous thm
but what does that make I?
I get what ym
but then what sorta triangle does that make? i can't visualize it
umm like it would be better if u join I with the pt on AD and the mid pt of BC
right triangle
what how
OH
BRO
THAT'S SO OBVIOUS
oml i need to get myself checked
thanks yall
root 8 then
yeah then add root 8 with 2
np
Closed by @zenith mural
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.
not sure how to do this
i made it 1 - (2cos^2 (t) - 1) + (2sin(t)cos(t)) / 1 + (2cos^2 (t) - 1) + (2sin(t)cos(t))
brackets.
or TeX.
anyway:
better is $\frac{1 - (1 - 2\sin^2(\theta)) + 2 \sin(\theta) \cos(\theta)}{1 + (2\cos^2(\theta) - 1) + 2 \sin(\theta)\cos(\theta)}$
Ann
clean shit up first
2sin^2 (t) + 2sin(t)cos(t) / 2cos^2 (t) + 2sin(t)cos(t)
brackets
(or, again, LaTeX)
otherwise i'll start misreading this on purpose
and now you factorize what you can.
sorry
yeah i done it now thank you
.close
Closed by @fluid dove
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• 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.
Okey so
I understand the distribution curve and that it is right skew, , however I don't really know how to estimate the average of the 10,000 policies
Sooo umm I need like the $\frac{\mu}{\sqrt{\sigma}}$ which is $\frac{150}{\sqrt{10000}}$
Alphurion
so I get 1.5 from that............. I think
Which makes little sense... cause if thats 1.5 dollars then... maybe thats meant to be 150 dollars which makes 160 dollars outside the range
So maybe I say yes it is safe to say the average loss is under... but i not sure
maybe it means 1.5 times... something is the average
so N( 10000, 1.5)
how do I z score this? who knows...
helpppp
ok fine ummm $\frac{\overline{x} - U_{0)}}{\frac{\sigma}{\sqrt{n}}}$
whyy
Alphurion
close enough
$\frac{160 - 150}{\frac{300}{\sqrt{10000}}} = 3.33 \overline{3}$
but idk the meaaaaaaaaaan
WAIT
160
$ = 3.33 \overline{3}$
cmooon
do ittt
$ = 3.33 \overline{3}$
hullloooo
$hellooo$
WAT
💔
Alphurion
whatev
R u tryna solve smth like this
this works
og question
Is that related to probability
It's a standard deviation question
So ummm
Er
its the confidence interval kind of, its like how sure are we that the average is below 160$
Well till that point u r going correct
Standard deviation is a measure of spread of the data
okay okay thats good
but what does 3.33333 represent though..
Cause I need to know how sure I am that the average will below 160$
but I'm not sure how that number helps, you know?
I mean, I would harken to the referenced "Example 15.8" at the bottom of that screenshot
Thought that too
hrmmm
this is like an example
so I have.... the mean... I think thats 3.3333
no.. but its not money
OH wait so do I z score the mean
er the sigma
and then itll maybe work out?
P(z >3.33)
so I need the z score of... 160?
Yes
so $z = \frac{x - \mu}{\sigma}$
Alphurion
$z = \frac{160 - 150}{300}$
Alphurion
Over 300?
should it be 3.333
Yes
okay
Why did I want this number...
OH
p( 3.33 >= 3.333) ...
wel actually I got like 3.00003
because 10/3.3333
Why 10/3.33
300/root of 10000?
oh, 3
o..
u right
so its less than, so it isnt true right
p(3 >= 3.33) is flase
Yes
No bro wait
D:
Its gonna be less than 160
Oh, because the number is less/
Ye
like the statement is false, so it is less, therefore this is a good investment
This one unfortunately doesnt
But atleast its done
Thank you for helping me out
Np
Closed by @proud kiln
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.
hello how would this loo like
The graph y=x squared is reflected in the line with the equation y=x to give me the curve C (a) sketch the graph of y= x squared and the curve C
i got something like this but idk what to do
in general what do you get if you reflect a function across the line y = x
the negative of it?
nope
then
thats if you reflect it across the x axis
reflecting across the line y = x produces the inverse function
wdm
how can i even draw that
is only possible to flip it oppositly
or reflect it on the sides
solve for x
x= +-root y
so the inverse function is?
root of the y value
x = +/-sqrt y is the same thing as y = x^2
reflected function should still have y as the subject
but u said solve for x
yh
the graph of the square root function is what your question is asking for
I get what youre saying but it's slightly wrong in how youre presenting it
For a function to be invertible it has to be one-one, that's why y=x^2 in its base form has no inverse
yes i guess inverse is the wrong term
but the loose idea of a square root being inverse to a square function is decent enough without needing to bring up bijections
+/- sqrt x is the reflected function @rare holly
Closed by @rare holly
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 with this limit, i dont know where to start i have plugged 0 but you get 1 over infinite
does the structure of the limit feel similar to anything else
limit defintion of a famous constant
sorry idk
do you know the limit definition of e
damn i didnt know what that was
i just googled it
but this is such a specific case
i feel like these kinds of questions are not uncommon in a school setting
literally got this limit from last years calculus midterm
oh i thought u meant are not common
yeah no ive seen this kind of limits like a hundred times
really
getting sidetracked
because u got to remember that x is approaching 0 and then all the other bs
using the limit definition can you see how it can be manipulated
theres really only 2 limit definitions for e
and they can be mutually derived with a substitution
i still dont know what to do tho
basically you want the same thing in the parenthesis and the denominator of the power
ok how can i do that
btw this is the one we're talking about right
yes
ok
yeah
it stays there
so its 1 + 6x)^1/6x*2
so is this wrong?
ok oops i missed the *2
now use the limit definition
well the definition doesnt have the *2 thing
well think about whether the definition would still have been valid if there was any other real constant in place of the 1 in the numerator of the fractional exponent
with indices rules its equivalent to ((1+6x)^1/6x)^2
ok now im lost
this would be easier if i knew how to use the latex bot thing
$((1+6x)^{\frac{1}{6x}})^2$
ashy!
ooh first try
because a^(bc) = (a^b)^c
practice and practice
dont try to memorize. understand! the logic behind
it should come naturally but its complicated
foundationally the indices rules show be engrained into your brain
its easier said than one
done*
anyways
we have this
well there is a direct result for 1^(infinity) forms but this problem was so simple that the way ashy was instructing you is the best
which the definition doesnt have
so with the ^2 what would it be
"simple" 😭 im trying my best
yes 😭
btw you can only ignore the powers in the limit if it doesnt create an indeterminate form
and the limit exists
meaning?
if it was an ^infinity instead of ^2 you cant do that
if it looks like it wont give you any trouble (😃) its probably fine
$lim_{x\to0}{f(x)^{g(x)}}=\exp{\lim_{x\to0}{(f(x)-1)\cdot g(x)}}$ \ where $f(x)\to1$ and $g(x)\to\infty$ as $x\to0$
T&C
haha but this is a direct result from the same definition. however it is derived by taking the natural logarithm on both sides first and then taking the limit
i understood this better
well thank you guys so much for helping
.close
Closed by @vestal pelican
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, I need help.
This notation is not mentioned in our textbook nor was it covered in class (calc 1).
I have attempted to apply the quotient rule, here, though I don't think I know how it applies here, or, how to configure that application properly.
I might be jumping the gun on needing help. But I'll keep this channel open for now, and wait for anyone to show up as I run through it again.
this is the leibniz notation of derivative
$\frac{\dd}{\dd x}\left(\frac{h(x)}x\right)\eval_{x = 2}$
this essentially means calculate the derivative of h(x)/x, then plug x = 2 in
I do not have enough tools at my disposal to do that, because I have not seen this before.
I do not know where to start.
I have found derivatives for a myriad of other problems leading up to this point, but not one where the only information given is h(x)/x.
@lunar egret Has your question been resolved?
I have attempted to apply the quotient rule, here, though I don't think I know how it applies here, or, how to configure that application properly.
in this situation
with a problem that looks like this
Closed by @lunar egret
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• 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.
When doing points for parabola… and using the table method, how do I know what value for x to put?
Well it depends
Do you know the vertex
When you are given a vertex?
@carmine juniper Has your question been resolved?
the vertex is where the parabola turns, finding then plotting the vertex first will let you choose x values around the vertex that when plotted, will give you a clear view of how the parabola should be drawn
find the vertex point of
x^2 + 2x + 1
you think what you can do after that!
the image is NOT how x^2 + 2x + 1 is drawn btw
its just an example of what a vertex is
I'm also assuming you know how to find it...
There are other ways like finding the roots and where the parabola intersects with hte y axis
but the table method doesnt require it
actually... there are so many ways 😭 you need to choose one
or tell us what your teacher wants you to do
get the key values,
and use whatever values are nice to evaluate
(the more values you use the better your graph will look)
Yes
But if they already know it there's no point
@carmine juniper Has your question been resolved?
Is her question on how to find the vertex of a function?
@carmine juniper Has your question been resolved?
@carmine juniper, is your question on how to find the vertex?
You gotta answer or else you might not be getting help
@carmine juniper Has your question been resolved?
.close It's been an hour since the bot message with no reaction so I'm guessing something went wrong
Closed by @ivory basin
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.
wai
$1<x<2 \implies 1<√x<√2$
wai
well
this is the CDF
yes
$2y \cdot \frac{2}{y^4} = \frac{4}{y^3}$
wai
yes
What is x
wai
what happens with y
wai
$\int_{0}^{t} \frac{10-(z-y)}{50} \cdot \frac{(10-y)}{50}dy; 0<t<10$
why is (10-y) squared
typo
wai
the limit of the cdf
that's z
then what should the limits be
well $F_Z(z) = \int_{-\infty}^\infty f_X(z-y)f_Y(y) \dd{y}$
kheer257
the thing that's limiting your integral is that f_X and f_Y become 0 in certain ranges
what is the range of Z = X + Y?
(0,2/5)?
.
@sharp smelt 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 help me w this please?
factor out 2 from the denominator on the left side
can you describe me why we do that and all that please?
any algebraic expression you want to simplify as much as possible before doing anything
4 and 2 share a common factor
okay after that?
write it out and see if you can continue simplifying
well im very new to this "high" level of math ik this is not that high but in my country this is high level graduation in math and highschool and i wanna do that but im afraid i will be too stupid for these
so im not sure whats next actually :/
did you write out what the denominator equals
.
Lets make this simple
Given an equation in the form a/b = c/d, you can ALSO say that a/c = b/d.
Then that gives you two linear eqns
that's actually harder than my suggestion
Yea true
nah i get it
yes
no
damn
factor 2 out of 4p + 2q means 4p + 2q = 2 * (2p + q)
plug the right side into the the original fraction
but how do i do that?
im not really sure what you say cuz my english math is very bad ngl
replace 4p + 2q with 2 * (2p + q)
okay
and you can do that because of
so 2p+q/2*(2p+q)=10p/9q right?
what now my friend?
riemann
c / c = ?
1
@plush bramble so the solution is 1?
nope
i write 1/2 * q/q
yeah
okay and after that?
then u have 1/2 = 10p/9q
i dont understand sorry
what dont u understand exactly
u simplified a fraction, u still got the rest of the equation
so we got 1/2*2p+q right?
no
$\frac{2p + q}{2p + q} = ?$
riemann
use this
and
ye i write this and after that?
what do u have on ur paper at the moment?
we can't tell unless you show what you have
if you didn't make a mistake you should have this
ye well its not

im stuck here
.
.
1/2* 2p*q?
no
$\frac{2p + q}{2 (2p+q)} = \frac{1}{2} \times ?$
riemann
but you told me to simplify dont you?
yes
and also how we got 1/2
because u simplified
hes trying to explain you what simplifying is
heres a number example
you simplified incorrectly
ye ik what simplyfying is but i dont understand why we got 1/2
answer this
using this logic
2p/4p*1 right?
no
read this as many times as it takes
how are u getting to these results?
try writting it on a paper
so we can see what ur actually doing
why did u cut stuff on one side of the equation and change stuff on the other side?
i dont know man 😭 im confused so hard now
u probably should get back to some easier problems
this is only the first step to solving ur problem and it doesnt seem like were making much progress
like im not that kind of stupid belive me i just not always understand what you guys awnt
want
my english math is really bad
thats why i got confused and write these stupid things
this is my first time writing in this server so i dont really know how all these works
no1 is calling u stupid
u have written the equation correctly, english wouldnt be an issue here
its basic algebra thats the issue
u shouldnt be afraid to take a lil step back and re-learn that
@nocturne owl 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.
my question was in fact, not resolved
"i need to find a distance for a test mass m_2, i have the acceleration which is shown as the equation for g, which to get the v_f i multiply by time.
the problem is that to use g, i need a distance, which must be the previous distance. i need to be able to use d as a smooth function (not jumping from the d value at one second to two seconds)"
i have d_i (or d(0)), m_1, G, v_i and time is to be input, im trying to "solve" for d, however since d is in the equation for d, i cant exactly do that, if i used a regular function of d(t) then that wouldnt be smooth
this might be at a post graduate level
heeeeelp
<@&286206848099549185>
@quasi lynx Has your question been resolved?
@quasi lynx Has your question been resolved?
assuming that d = d(t) in both places, why not multiply both sides by d^2? you would then be finding the roots of a cubic polynomial. (it appears to be solvable assuming G = G, and that velocity and mass are >0)
that being said, i am a little unsure what the setup is exactly here, and this formula strikes me as weird if im honest. are you averaging the velocities to get distance?
this is just /\d= (v_i + v_f)/2 but with v_f being the gravitational acceleration multiplied by time
and multiplying by d^2 doest get rid of the d
i thought it was $\Delta d = \frac{(v_i + v_f)}{2}t$, i.e. $d = \frac{v_i t + \frac{Gm_1}{d^2}t^2}{2}$? but i digress
ηασιβ ♥
it doesn't get rid of the d, but it gives you a cubic polynomial you can solve for 3 "possible formulas" for d
right now this is some kind of recurrence relation, but those 3 solutions will depend solely on v, t, G, and m. they would be messy, though
i feel as though my eyes have been burnt, looking it up with some ai (not the bad kind) assistance, it seems very complicated
oh no did i write it down wrong.... is the original displacement equation multiplied by time...
shit
oh god its worse now, oh lord
ahhhh, thanks ok bye
.close
Closed by @quasi lynx
Use .reopen if this was a mistake.
help plsss
hence why i was wary about the formula 😭 but if this is it, then i would solve for 3 potential formulas and eliminate incorrect ones (e.g. a formula that assumes distance is less than zero)
this channel hasn't opened yet - how about #help-30 or any channels in the available category?
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.
Hello! I am just reviewing a linear algebra exam I had a couple days ago, here is the question.
I thought both (a) and (b) would be valid diagonalizations because they just have their eigenvalues and associated eigenvectors swapped, but the answer key only says answer (a). Are both options diagonalizations?
I also plugged them in, and they both worked
yes theyre both valid
alright, I will just have to talk to the professor then I fear, thank you for the help!
np
.close
Closed by @ember zinc
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.
For part b isn’t the range where f’(x)> 3/4? I thought it would be just above the y-intercept why is it 1/2? thanks
Help me
can u restate yr query?
Why is the range of the inverse f’(x)>1/2? idk where they got 1/2 from and I thought it would be instead >3/4 (because that’s the y-intercept)
wait wait im rechecking
yes u r right it should b 3/4
i cant think why would it b 1/2
Closed by @mortal wolf
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• 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.
彡+开
I can see 5 shapes, before I saw just crumples
4 disks in a disk in in a disk in a space?
@void grail 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.
Do you know about the remainder theorem?
hm i don't think this question will be solvable if you dont know that. not much information has been given
well simply put, the remainder theorem states when a polynomial P(x) is divided by a linear of the form x-b, the remainder is simply the value of the polynomial at x=b, i.e, the remainder when P(x) / (x-b) = P(b)
oh ok ..how do we use that here
from this theorem, a result can be derived which sates that when P(x) is a polynomial with integer coefficients and at least one integral root for any integers a and b, P(a)-P(b)=P(a-b) which is divisible by (a-b)
yes, but this wont help us much. lets assume a=2 and b=the integral root of the polynomial
so P(b)=0
now P(2)-P(b)=13-0
so 2-b divides 13
can we say that?
P(2) is in your question
oh ok now i can cross check w the options and get the ans from this only
now what is one special property of the number 13
prime no.?
yes
so what can we say from that
you tell me if 2-b divides 13 and 13 is a prime, what can we say about 2-b
its prime?
if a number is prime, then only 1 and the number itself can divide it
so 2-b has to be 1 or 13
got it?
yea
but here we're dealing with a polynomial so it may have negative roots too, so we've also consider -1 and -13
so 2-b= -13 or -1 or 1 or 13
now can you find the possible values of b?
similarly you've to repeat this process with 10
oh alr alr was just abt to ask what about P(10)
you've to repeat the same process with 10, again assume the root to be 'b'
you'll find another set of values
the root 'b' will be the one which is common to both the sets
Closed by @eager 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.
• 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.
It's asking for the positive of tanx - cotx and the answer is 3 but I want to know how it's done
Also I accumulated some of the questions I couldn't solve is it okay if I can ask all of them here?
,rotate
consider what
(tan(x) - cot(x))^2
expands to
Yoo guys Hlp me with an question
!occupied
Someone else is already using this help channel. If you need help with a question, please open your own help channel/thread (see #❓how-to-get-help for instructions).
You can't close someone else's thread
You don't get to decide if someone else has a doubt or not
11 - 2tanxcotx = (tanx-cotx)²?
If,X=2(3-x) and Y=2(2-x)
Then,
X-Y=?
That seems good to me
What?
Help me with this pls
Why don't you use another room instead?
It was said to get your own channel
Ok
Do you see where to go from here?
Not really
Notice the 2tanxcotx
OH
Can you do something to simplify this?
So 2?
Yep
Yeah
Can you also check this one out?
It's asking for tan but I don't know how to solve it
The solution is sqrt(7)/3?
You can draw a perpendicular from A, which bisects 2beta
Yeah
So a + b = 90
Oh
Yeah, but you know sin(beta)
I got it thank yoy
Great 🙂
The answer is E
I need to find cotx to find tanx here?
I tried to find |AT| but it's too complicated
Actually, finding AT seems to be a good move
If angle TAO’ is 90-alpha, what is the angle AO’T?
Not that much
Write down your Pythagorean theorem
You forgot to square the 3r
Wouldn't -r² be -r and 3r sqrt(3r)
No, you would have $(3r)^2=r^2+x^2$
FriedRiceKing
x=2r?
$(3r)^2=r^2+x^2 \ 9r^2=r^2+x^2$
FriedRiceKing
Ha I see, that happens
Yep
Yeah thank you
You know where to go from here?
Yeah
👍
.close
Closed by @desert patrol
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 you solve these questions?
Yeah
there’s a formula for this
sinus theorem idk
is there any angle given?
you need the area no?
I see
Is BAC 90 degrees?
If that’s the case it’s quite easy
Actually isn't cotB+CotC
Just BD/AD+CD/AD= BC/AD
So it's just 8
I was overthinking it
You are right😭
Can you help me with this one as well?
It's asking the solution for cos³x/1+sinx
what do you think?
I couldnt't figure it out
you know cos^2x =1-sin^2x?
I'd do $\cos x = \frac{1}{1 - \sin x} \frac{1 + \sin x}{1 + \sin x} = \frac{1 + \sin x}{\cos^2 x}$
south
omg I just gave you the answer
try to think and fill in the intermediate steps yourself
@desert patrol 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.
Is it possible for a singular square matrix to have LU decompositon without the Piovting matrix P?
Let's say that the linearly dependent row is the last one, so I get a 0 for the last row of U ?
@rapid wagon Has your question been resolved?
well just pick literally any singular triangular U you want and pick L=I
and then A=LU
Oh..
What if A is symmetric?
Singular square symmetric matrix can have a LDL^T decomposition?
So how I know is that symmetric PD matrices for sure always have a LDL^T, so if i broaden the range and go to symmetric, it doesn't always work, because if the matrix is singular then i will have 0's in the diagonal of U so I can't do U=DL^T
Then again what if the zero is in the last row of U?
LU decomp is literally just gaussian elimination but fancy
of course there are symmetric matrices that you can do gauss on without having to switch rows at some point
wdym you cant take U=DL^T
under what def of LU decomp are you working
I mean if the matrix is symmetric and PD then the decomp can look like LDL^T where U=DL^T and D is a diagonal matrix with the diagonal of U, L^T is unitary upper triangle but the elements are "normalized" because i divide by the diagonal element for each row, and if the matrix is singular and I have 0 on the u_ii then i cant divide the row ii by 0 so LDL^T decomp doesn't exist for it
I see, that answers my question ig
If i think of it like that
Buhh
If u dont have anything to add i will close ok?
.close
Closed by @rapid wagon
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 I ask a question?
you seem to have already asked a question :)
injectivity looks good, surjectivity is correct, but i think the proof could be clearer.
something like "let a in A" at the start, then at the end you say "f(a,b) = a for any a in A, so surjective"
i.e. just making it clear that you are picking an input for all possible outputs
which proof, c1 or c2?
both of c1 and c2, specifically about surjectivity
where do I say "for any a in A"?
right at the start should be good
something like: \
For any $a \in A,$ pick $(a,b) \in A \times B.$ Then $f(a,b) = a$, so $f$ is surjective
ηασιβ ♥
isn't mine saying the same thing? "if a is in A" implies not just one element but all elements in A?
what i think they're trying to tell you is that proofs are better and more clearer to read and understand if you use a bit of language
yeah, the way you wrote it, it felt like you were setting the input as arbitrary, as opposed to picking an input based on the output
according to an online solution C2 i. is not injective
?
this is the online proof
um? the proof basically says that f is injective and then the last sentence is the opposite
yea I don't understand
you see that it ends with a=c and b=d which is like the definition of injectivity, right?
maybe im losing it but that seems like a typo to me
indeed a typo
ok
so in this example, you are including all possible inputs of A x B, whereas in my solution it was choosing arbitrary a in A and b in B which only covered one input?
@thick musk Has your question been resolved?
.close
Closed by @thick musk
Use .reopen if this was a mistake.
Is D 1-3?
I think 1 and 2 are correct
3 I am having a bit trouble fully understanding
with 3 g(f(x)) => g(1/x)
^ at that step we need to evaluate the domain (0,1) to ensure every g(1/x) is defined?
then we go from g(1/x) => ln(1/x)
^ at that step we still could only evaluate x with the domain (0,1)?
so basically my question is if both F and G have different domains, we actually only evaluate the composition of both F and G within the domain belonging to the function that is being composed with? so in the case of G composed with F, we evaluate 'x' within the more restrictive (0,1) domain and if F composed with G, we evaluate 'x' within R->R?
✅ Original question: #help-39 message
Is this true?
@thick musk Has your question been resolved?
Yes
If you are finding F(G(x)), the function is only defined when:
- x satisfies the domain of G(x)
- The values of x where the image of G satisfy the domain of F.
Closed due to timeout
Use .reopen if this was a mistake.
.reopen
✅ Original question: #help-39 message
Why does it not look well defined?
Because the domain of g is all real numbers
But
That's definitely not so, if g(x) = ln(x)
But it’s g(1/x) such that x is in this interval (0,1) making it defined for g(x)
1/x defined in the interval (0,1) results in a value that is in R (domain for g(x)
@thick musk 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.
AB=5, BC=6, AC=9, incircle tangent to BC and AC at D and E, AD and BE intersect at F, find CF
how do you do this without bashing like every single length 
barycentric coordinates?
havent studied that
bary bashing 💀
menelaus spam 😭
huh i forgot menelaus existed
is it to scale?
hello fellas
i made it so yeah
Welcome to mathcord @solemn kernel
This is a help channel, go to #discussion for casual conversation
also bro did you take amc 12
no
BD=1, CD=5, AE=4
I think you can do ||mass points|| followed by ||Stewart's if you extend CF to meet AB||
extend CF to meet AB at X
if im not mistaken X is the other tangent (?)
ye gergonne point
ok yeah this works
from stewarts 6^2×4+9^2×1=5(CF^2+4×1)
CF=sqrt41
put B=4 A=1 which gets C=4/5 i think?
then X=5
Ngl I didn’t actually crunch the numbers lol
orz
.solved
Closed by @dapper kraken
Use .reopen if this was a mistake.
whar

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 tried
- using Bernoulli's equation
- substituting y = tanθ
The latter got me to this equation-
(x - e^θ)dθ + dx = 0
But idk how to proceed from there
i can give you a hint
try bringing the expression in terms of dx/dy instead of dy/dx
try playing around
you'll see that type it is
@gentle lichen
Closed by @gentle lichen
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• 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.
Trying to make dy/dx gives me - 2k²/y dx
What do I do with dx in the denominator
Is the equation even correct?
I feel like there should be a d(something) in the RHS too
<@&286206848099549185>
try to make d(y/x)
and then substitute it as t or something
What about the RHS
Yes
$d\left(\frac{y}{x}\right) = - 2\frac{k^2}{yx^2}$
If I integrate both sides
There's no dx or dy on the right
Dhruv
hmm i think youre right
theres something off with the equation
ill try solving it as they originally intended and lyk
👍
@gentle lichen 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.
guys am i doing something wrong here? why is my 5/2 negative?
what's f(x) there?
$-\frac{4}{1+2x} -\frac{3}{2-x} + \frac{5}{2-x^2}?$
donkey
this onee
You mathed wrong somewhere because it should be positive.
5(2-x)^-2
we’re supposed to bring the (-2+1) down right?
Wdym
You're supposed to divide it by -1
wait yes thats what i meant
But i have multiplied it by -1
Oh wait so multiply by -1 is for the derivative of -x?
That's from the -x, but you disregarded the negative sign from the exponent.
Yes
Ohhhhh
So it's supposed to be positive
