#help-10
1 messages · Page 276 of 1
Closed by @ember oar
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.
quick question:
in a probability distribution table, can x be something other than a number? Like yes or No?
.close
Closed by @white hinge
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
hi anyone able to help a bit with latex
trying to make a tittle page for lab report
Hello, I can't get a hang of the function domain
#latex-help for your latex questions
.close
Closed by @twin oracle
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
hi
@merry girder 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.
a little confused on how to do this
do i calculate the partial derivative with respect to z, then with respect to x, divide them (z/x) and then plug in 1 for x, y, z?
uh i think you can just implicitly differentiate
like apply d/dx to both sides of the equation
hmm
no
you have no dz/dx present which is the thing you want to solve for
d/dx(z^3x) is not z^3
and d/dx(2yz) is not 0
im confused
how is not z^3? Aren't you treating z^3 as a constant? like d/dx(3x) is just 3
no, z is a function of x and y
okay i understand that now. So I implicitly differentiate, right?
yeah
i got the problem wrong lol so it gave me a different one. Same concept but just different numbers
so im not entirely sure i remember how to implicity differentiate. So im differentiating with respect to x, right?
so d/dx(9xy) + d/dx(z^4x)...etc
so to start, d/dx(9xy) is 9, right?
how exactly do i implicity differentiate?
cuz there are three variables
y is constant with respect to x so d/dx(9y*x) is just 9y
z^4x is now a product of two functions of x
oh okay. so is d/dx(z^4x) = z^4 * dx/dz?
you're forgetting both the product rule and the chain rule
im just confused because z does not look like a function.
like i know chain rule is d/dx [f(g(x))] is f'(g(x)) * g'(x)
but i don't really see how chain rule can be applied here
so its really z(x)^4 x, right?
yeah, we just dont write it all the time
well sorry really z = z(x,y)
like the question says
but importantly its still a function of z so chain rule must be applied if youre partial diffing wrt x
here f(x) = x^4 and g(x) = z(x) [really z(x,y) but for this purpose its fine]
yeah but now these derivatives are really partial derivatives
i wouldNT use ' to denote them
wait so how would you denote d/dx (z^4)?
$\frac{\dd}{\dd z}(z^4) \cdot \pdv{z}{x}$
ΣΑCu
so would this be correct ?
uh no
you didnt finish evaluating this
yes
and the derivative you have here should really be a partial derivative
so is this right?
yeah
and d/dx (-2yz) is that just -2y dx/dz?
dz/dx
so now do i just solve for dz/dx but moving everything to the other side of the equation?
yeah rearrange for it
i got dz/dx = (-9y-z^4)/(4xz^3-2y)
oh awesome. Yes and then i just plug in 1 for all the variables. Thank you so much @warm canopy
really helped me out
.close
Closed by @steel goblet
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 have a tridiagonal matrix with dimensions n x n, which is a symmetrical matrix. I know the eigenvalues of this matrix are real.
Now I multiply the first and last row of this matrix with a scalar. Apparently the eigenvalues of this matrix are also real. Is there a proof of this, or a theorem that says this?
I have tried to verify this using examples, and it seems to hold true for my case. However, I can’t seem to prove this myself, or find a proof of this online
Well if I multiply the first and last rows of a symmetric matrix with a scalar it is not symmetric anymore
ah sorry
My professor said that doing this is some sort of transformation, and since this transformation can be reversed, and the resulting matrix has real eigenvalues (symmetric again), the non-symmetric matrix has real eigenvalues.
mh,.. let me think
no its false
for example if you multiply only the first raw for a scalar ..then you could get a matrix that has not real eigenvalue
$\begin{matrix}\lambda &&2\lambda \ 2 && -1 \end{matrix}$
everg
everg
I was thinking of proving it using something like this:
Let A be a symmetric matrix with values a b 0 … 0 in the first column. Then the characteristic polynomial is equal to (a-lambda)d1 -bd2, where d1 and d2 are determinants. Let lambda be an eigenvalue. Then lambda = (ad1-bd2)/d1.
Since the eigenvalues of a symmetric matrix are real, the RHS is real too.
Now let B be matrix A after multiplying the first row with a real scalar c. Then its characteristic polynomial is (ca-lambda)d1-cbd2, where a, b, d1 and d2 are the same as before, but lambda is an arbitrary eigenvalue of this matrix B. Then we can express lambda as lambda=(cad1-cbd2)/2=c (ad1-bd2)/d1. Which is a multiplication of a real value and a real value, which must be real.
Doesn’t this hold up?
has det>0 and trace <0 ...impossible for real eigenvalue
you did a proof for a symmetric matrix and then you change only the first row by multiplication ?
Well we can also assume A to be an arbitrary tridiagonal matrix with real eigenvalues. Point is that (ad1 + ad2)/d1 is real, and a real value multiplied by a real value is always real
Or did I do something wrong?
sorry i can t follow ..now i am very tired ...maybe there are more energic guys here
No worries, thanks for the effort
@unreal storm Has your question been resolved?
<@&286206848099549185>
@unreal storm Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
can i get some help with this
I assume you have learned how to actually find an explicit antiderivative?
@fair girder Has your question been resolved?
is that the one with numbers on top and bottom of the S
Edward II
anyway
uh yeah except I'm questioning the x^2
?
definite integral
thats just some example i found
explicit antiderivative is definite integral?
yea i have
oh
then it gets much easier
so $\int_0^9f(x)dx=F(9)-F(0)$ and rearrange, and the integral is the area under f
Edward II
yes
and now f is really nice to calculate the area under because it's all triangles, rectangles, and a missing semicircle
(unimportant: by find an explicit antiderivative I meant FTC and forgot the theorem's name 💀)
yes
i know how to find the first two
the triangle and rectangle
how would i find the area outside the semicircle?
from 4 to 6
those curved triangles
riemann
?
well, if the semi circle wasn't there it would be a rectangle
true
and we've 'cut' a piece out
alr one sec
ah i see
so i get 1 for triangle then 3 for rectangle and then circle is pi*r^2 so pi(1)^2
and then from 6 to 9
they cancel out cuz they are symmetrical
so the second rectangle is 3 but we cut out the semicircle which is pi/2 so 3-pi/2
plus the 4 from the triangle and first rectangle
7-pi/2
so thats F(9)
and then -F(0) which is 2
so 5-pi/2
right?
oh wait
we dont need to subtract the F(0)
its just asking for F(9)
and on rearranging this you need to add the F(0) to the LHS that is the area
you overestimated the area by two and didn't add
why do i have to add the F(0)?
we want just F(9) right
yea
so we have 'area' = F(9) - F(0), so F(9) = area + F(0)
oh yea makes sense
cuz this is the area of whole thing
ok i got it
alr ty again
.close
Closed by @fair girder
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.
are these correct?
im pretty sure they are
<@&286206848099549185>
<@&286206848099549185>
.close
Closed by @unreal whale
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 this question
Its integral of (-3cscx times cotx) dx
@white mulch Has your question been resolved?
Closed by @white mulch
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
hello
The amount of a certain medicine, in milligrams, in a patient’s body t hours after an initial dose can be modeled by the exponential decay function f given by f(t) = ab^t. An initial dose of the medicine is 10 milligrams, and after 2 hours the amount in the body is 5 milligrams. At what time will the amount in the body be 0.01 milligram? (Assume no additional doses of the medicine are given after the initial dose.)
i don't understand this problem at all
have you learned half life
.
Have you learned half life?
what is that
it means every set number of time, something will be halfed, in this care, its the medicine
every 2 hrs
so how many times of 2 hrs do it need to pass to have only 0.01 milligrams left?
idk
In this video we go through 3 word/story problems involving writing and solving an exponential growth or decay function. We discuss how to identify the initial amount, rate of growth or decay, and the time.
Join this channel to help support this free YouTube content:
https://www.youtube.com/channel/UClOR1BiPyOkkIAnv9Cmj4iw/join
Take Your Lear...
that will help you understand how to do ur problem
@timid silo Has your question been resolved?
@timid silo 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.
Trying to figure out the correct domain for f(g(x))
first, what is f(g(x))?
F(g(x)) is also (f•g)(x)
can you write it out in a formula form with $x$ and numbers in it?
Dee3Cay
not just $f\circ g(x)$
Dee3Cay
I believe I wrote down 1/(1/(x-9)+(3/1) for that
ok now you'll need $x-9$ to not be 0, also, $\frac{1}{x-9} +3$ cannot be 0 too, why?
Dee3Cay
I do not know
here you wrote $f\circ g(x) = \frac{1}{\frac{1}{x-9}+3}$
Dee3Cay
so now do you know why?
Yes because I subsitituted g(x) for x in the equation of f(x)
Dee3Cay
Oh shit. Is it actually 1/(x-9)+3/1=0
yes
So combined I got 1+3/(x-9+1)=0
I hope that’s correct for now
4/(x-8)=0
@timid silo Has your question been resolved?
Closed by @quiet shale
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
now I know this would lead to an improper fraction
and then turned into a mixed fraction
wait bruh Im stupis
.close
Closed by @junior jay
Use .reopen if this was a mistake.
.reopen
✅
so the mixed fraction would b
but how do I make this into a %
<@&286206848099549185>
just write 2 as a percentage, 3/5 as a percentage then just add them together
@junior jay what is 3/5 as a percentage?
@junior jay 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.
have you learnt about free variables
Yes
okay can you identify which
They are the one's not with leading 1's
the non leading ones
that will be when its in reduced echelon form
So x2 and x4?
Could anyone help me with this sheet of work, I am year 7 and I cannot wrap my head around it.
look at x4 again
!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.
Sorry x2 and x5
very good
What do you mean by this
I mean i know what reduced echelon form is
Isn't this in reduced?
apparently we're expecting 3 free variables? hmm
have you seen the form where its only
1 0 0
0 1 0
0 0 1
Ok i get it this is in echelon form but not reduced
I tried reading what to do next but i don't quite get it
It says we make the leading variables subject of formula?
anyways lets proceed
yeah
so who will be s and t
x2 and x5
okay, now write the equations for this augmented matrix
with those substitutions
Wait so if we substitute x2 with s how will we get x2
S
exactly
Or?
we'll be expressing x1,...x5 in terms of s and t
Hmm okay well let me work it out gimme like 3 then you'll confirm?
np
$$\begin{bmatrix}
x_1 \
x_2 \
x_3 \
x_4 \
x_5 \
\end{bmatrix} = s \begin{bmatrix}
? \
? \
? \
? \
? \
\end{bmatrix} + t \begin{bmatrix}
? \
? \
? \
? \
? \
\end{bmatrix} + \begin{bmatrix}
? \
? \
? \
? \
? \
\end{bmatrix}$$
ping when you're done take your time
.
Y es
then we let them s and t s,t in R
So meaning X2 and X5 is s and t
now now want to find the other variables x1, x3,... in terms of these
yeah
Hmm
still not clear?
A friend of mine
did what
1
are these her free variables
Yes
in this matrix do we have x3 and x4 are free variables
is that the matrix your friend was working with
I have no idea tbh
Same as mine
you gave me a link to this matrix?
if its the same as yours then its plain wrong the beginning
Yes
Im new to this topic 🥲
Ok so the free variables are the one's in not leading 1's
So i was wondering here there are no 1's
non pivot ones
I don't know what that means🥲 iv seen it somewhere tho
or if you want to check with that method of leading ones then you have to further reduce the matrix
eh okay lets do this then
to reduced row echelon form
I end up with
$$\begin{pmatrix}
1 & -2 & 0 & 0 & \frac{5}{3} & -\frac{1}{3}\
0 & 0 & 1 & 0 & 2 & \frac{9}{2}\
0 & 0 & 0 & 1 & \frac{7}{3} & 3\
0 & 0 & 0 & 0 & 0 & 0
\end{pmatrix} $$
look at these two and tell me what changed
Omg same
do you now see how you can get the free variables
with or without the reduced row echelon form
no need for the leading 1s definition
Wait
okay then now identify for here
yeah
So
Here X2 is and x5 is s and t and the other x1 34 are in terms of s and t
x1, x3, x4 yes
im about to show you why and a cleaner way to show that
Ok perfect thank you so much , are there any resources i can refer to which can further explain to me
Ok please do so
hmm
give me the x1, x2, x3, x3, x5 first
Also is there a shorter way than this for getting the reduced row echelon form
:Xd: i learnt from many places checkout #book-recommendations for a linalg book
row operations are the way to go

now fill in 
$$\begin{bmatrix}
x_1 \
x_2 \
x_3 \
x_4 \
x_5 \
\end{bmatrix} = s \begin{bmatrix}
? \
? \
? \
? \
? \
\end{bmatrix} + t \begin{bmatrix}
? \
? \
? \
? \
? \
\end{bmatrix} + \begin{bmatrix}
? \
? \
? \
? \
? \
\end{bmatrix}, s, r \in \mathbb{R}$$
copy paste code
now fill in 
$$\begin{bmatrix}
x_1 \\
x_2 \\
x_3 \\
x_4 \\
x_5 \\
\end{bmatrix} = s \begin{bmatrix}
? \\
? \\
? \\
? \\
? \\
\end{bmatrix} + t \begin{bmatrix}
? \\
? \\
? \\
? \\
? \\
\end{bmatrix} + \begin{bmatrix}
? \\
? \\
? \\
? \\
? \\
\end{bmatrix}, s, r \in \mathbb{R}$$
now fill in 
$$\begin{bmatrix}
x_1 \\2s-(5/3)t-(1/3)
x_2 \\s
x_3 \\(9/2)-2t
x_4 \\3-(7/3)t
x_5 \\t
\end{bmatrix} = s \begin{bmatrix}
? \\
? \\
? \\
? \\
? \\
\end{bmatrix} + t \begin{bmatrix}
? \\
? \\
? \\
? \\
? \\
\end{bmatrix} + \begin{bmatrix}
? \\
? \\
? \\
? \\
? \\
\end{bmatrix}$$
iamlegendd
💀 just fill in the "?"
Oh no😂
lmao
s \begin{bmatrix}
? \\
? \\
? \\
? \\
? \\
\end{bmatrix} + t \begin{bmatrix}
? \\
? \\
? \\
? \\
? \\
\end{bmatrix} + \begin{bmatrix}
? \\
? \\
? \\
? \\
? \\
\end{bmatrix```
these ones replace the ?
With?
uh
.
if its faster do on paper
this is a nice way to combine all the equations into one
Yes
x2 can be written as
x2= s + 0t + 0 right
Yes
what about x3
0s -2t+9/2
0s+t+0
okay good
so now we have
x1 = 2s-5/3t-1/3
x2 = 0s -2t+9/2
x3 = 2s-5/3t-1/3
x4 = 0s - 7/3t + 0
x5 = 0s+t+0
right
Yessir
now look at this again
see we are repeating the same thing over and over
whats the neat way to group all of that
What same thing ..like the s and the t?
yes
how can i write those as a vector
Ooh mhm
this is the biggest clue ever
yeah can you now fill in
x_1 \\
x_2 \\
x_3 \\
x_4 \\
x_5 \\
\end{bmatrix} = s \begin{bmatrix}
? \\
? \\
? \\
? \\
? \\
\end{bmatrix} + t \begin{bmatrix}
? \\
? \\
? \\
? \\
? \\
\end{bmatrix} + \begin{bmatrix}
? \\
? \\
? \\
? \\
? \\
\end{bmatrix}, s, r \in \mathbb{R}$$```
just copy paste
s \begin{bmatrix}
? \\2
? \\0
? \\2
? \\0
? \\0
\end{bmatrix} + t \begin{bmatrix}
? \\
? \\
? \\
? \\
? \\
\end{bmatrix} + \begin{bmatrix}
? \\
? \\
? \\
? \\
? \\
\end{bmatrix```
replace the ? with your answer :Xd:
Like this?
x_1 \\
x_2 \\
x_3 \\
x_4 \\
x_5 \\
\end{bmatrix} = s \begin{bmatrix}
2 \\
0 \\
2 \\
0 \\
0 \\
\end{bmatrix} + t \begin{bmatrix}
? \\
? \\
? \\
? \\
? \\
\end{bmatrix} + \begin{bmatrix}
? \\
? \\
? \\
? \\
? \\
\end{bmatrix}, s, r \in \mathbb{R}$$```
continue
$$\begin{bmatrix}
x_1 \\
x_2 \\
x_3 \\
x_4 \\
x_5 \\
\end{bmatrix} = s \begin{bmatrix}
2 \\
0 \\
2 \\
0 \\
0 \\
\end{bmatrix} + t \begin{bmatrix}
? \\
? \\
? \\
? \\
? \\
\end{bmatrix} + \begin{bmatrix}
? \\
? \\
? \\
? \\
? \\
\end{bmatrix}, s, r \in \mathbb{R}$$
$$\begin{bmatrix}
x_1 \\
x_2 \\
x_3 \\
x_4 \\
x_5 \\
\end{bmatrix} = s \begin{bmatrix}
2 \\
0 \\
2 \\
0 \\
0 \\
\end{bmatrix} + t \begin{bmatrix}
5 \\
-2 \\
-5 \\
-7 \\
1 \\
\end{bmatrix} + \begin{bmatrix}
-1/3 \\
9/2 \\
-1/3 \\
0 \\
0 \\
\end{bmatrix}, s, r \in \mathbb{R}$$
iamlegendd
yay
good job
OmG thank you so much!
yw
So is there like a place where we get this codes from?
you mean latex?
if the linalg you'll see it in your course soon
Hmm okay
One last question
Why were they saying there are 3 variables in the question
did we see 3?
Nope
probably a trick question
Did you check this?
i dont have access to that site
the only thing i saw is the matrix
my only advice is to look up linalg parametric solutions questions and answers
or just get a decent textbook recommendation from #book-recommendations
Great 😊
How do i close this thread
.close
.close
Closed by @unique tendon
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 I need help solving this function: f(x)=ln(1+3(x−1)^2). Im having trouble since the argument seems to never be verified because delta is always negative. Any help?
wym by "solving this function"
i need to find the largest intervals in which it is invertible and finding the equations for those inverted functions
sorry english isnt my first language
the solution starts by saying that this function is defined for all Real numbers
but i dont get how
since for a natural logarithm to even exist, its argument needs to be greater than 0
so i shouldnt try to solve for x
i'd say start by getting a good idea of how the function looks like
the thing is, that 1 + inside also changes things quite a bit
3(x-1)^2 is never negative
the lowest value 3(x-1)^2 can be is 0
which means the lowest value f(x) can be is also 0, because ln(1) = 0
so this eliminates you having to deal with any negative values for f(x)
yeah so
I mean, i wouldnt really be needing to solve anything if i was doing it myself
because intuition is all you need here, probably
im just having trouble visualizing the function
i guess im not really sure what the single things actually do on the plain
yeah we will get to that
i know that x^2 basically copies and flips the function and makes it symmetrical right?
so now i have something like this
because in reality your function is a slightly altered version to what theat looks like
yea that pretty much is it
you need to know three things
1- your graph is in this shape
2- your function intersects the x axis at x = 1
because of the +1?
yes
right
so you already know that the "branching" begins at x= 1
idts
im guessing this was just an approximate drawing
yes
shouldnt the function sort of compress if i multiply it by a number greater than 1?
yeah but like this doesnt matter for your question
right right
you want to find the largest interval for which it is invertible
yes
scaling (x-1)^2 doesnt change that
so one is smaller than x=1 and one is greater than x=1?
talking about the intervals in which it is invertible
yes
and noi i just need to express what happens in those intervals
and since i have basically two normal logarithms but flipped and slid to the right in both intervals i should represent that in the form of 2 equations
but theyre flipped so i have to do ^-1 too
how did e get there
@brazen raptor Has your question been resolved?
.close
Closed by @brazen raptor
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Channel closed due to the original message being deleted.
If you did not intend to do this, please open a new help channel,
as this action is irreversible, and this channel may abruptly lock.
Find all the clicks on the graphs in the image
someone pls
i cant find anywhere what clicks are or cliques
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.
Will it be going north leaning east at a 80 degrees angle at 608km/h ?
@heavy bramble 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.
hey guys, how to solve x< x^2 < |x|
x<x^2 means x-x^2<0 or x(1-x) < 0
this only holds between (-inf,0) and (1,inf)
the other part i forgot how
And x<|x| only holds between (-inf,0)
what about x^2 < |x|
that holds for (0,1)?
actually it holds for (-1,0) and (0,1)
okay but how do i formally solve it though?
You could divide everything by x which would give 1<x<1 when x is positive and 1>x>-1 when x is negative
The first one has no solutions
u can't do that?
u don't know if x is positive or negative
dividing without knowing its sign is kinda undefined
also |x|/x is sgn(x)
Hmm okay sure
@drifting roost Has your question been resolved?
Closed by @drifting 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.
• 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.
e
!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
1
are you familiar with the coordinate plane and graphing linear equations (and maybe inequalities) on it?
maybe not
then this problem is impossible for you right now, unfortunately.
Closed by @frigid gale
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.
who please know the definition to do it
You can just cancel u_2 + 7
Then u_3 + 7 etc.
Imagine cancelling a lot of diagonals
Which two terms will be left?
type .close to close this help channel. : )
@wise relic 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.
Hello, I have a question about Taylor series, a Taylor series has this form:
$f(x)=\sum_{k=0}^{\infty} a_k (x-a)^k$ However, this is only true when x is between a-R and a+R, where $R = \lim_{n \to \infty} \frac{a_{n+1}}{a_n}$
Şêro
Now the part I don’t understand is to find R
Can someone give me maybe an example?
Also I know how to find a_k
It’s just the kth derivative evaluated at x=a divided by k!
Do u have a specific problem in mind
Well let’s say f(x)=sin(x) and I choose a to be 0
Then what’s R
I just need to know what that limit means
How do I calculate that
What’s $a_{n+1}$
Şêro
in that case you use the next nonzero term relative to a_n for a_(n + 1)
So for instance $a_n$ would be $\frac{x^{2n + 1}}{(2n + 1)!}$
1/R is the limit you wrote, with absolute values
Oh yeah I forgot the absolute value
(and rather use limsup but that's out of the point for now)
But it’s when n approaches infinity
So what would be the next nonzero term
Ye im getting to that
Can you just give an example
$a_{n + 1} = \frac{x^{2n + 3}}{(2n + 3)!}$
992qqoloy
From where?
992qqoloy
From the mclauren series of sin(x)
$a_{2n} = 0, a_{2n+1} = \frac{(-1)^n}{(2n+1)!}$
rafilou2003
What’s the McLauren series
I just know the Taylor formula
Taylor series centered at 0
yes it's the taylor formula, $a_n = \frac{f^{(n)}(a)}{n!}$
rafilou2003
yes
But how can we find such a complicated limit
I mean we divide that all by the n+1 term too
And then take the limit as n approaches infinity
So R is the limit of |an/an+1|
I mean what’s the Infinitiv derivative evaluated at 0
there is no infinite derivativ
But we wrote $f^{(n)}$
Şêro
And n approaches infinity
we take the lim of f^(n)/f^(n+1)
f^(inf) doesn't have to exist
as I said, that would be in order to find 1/R
if you want R, you take an/an+1
Şêro
we don't
we take a limit of ratios
lemme show you
Yea but in that ratio is a_n and a_n is defined by the nth derivative of f evaluated at x=a divided by n!
as I said, lim (an/an+1) can exist without lim(an) existing
back to this
?
yes, so lim (-1)^n doesn't exist
Okay I see
ok so we don't care about lim(an) because it probably won't exist
we want lim(|an/an+1|)
What about n+1
Yes how do we get that
we don't care about lim(an+1) either
Okay
well, we compute for a given n, an/an+1
So does something cancel out in the ratio or what happens
Here as I said, since even terms are 0, we discard them
But in our case n approaches infinity
yes, so before we approach infinity, we compute it for a fixed n
Is that even allowed
Hmm
so before taking the limit
I see your point
we compute an/an+1 for any given n
So we choose like an easier n
Compute it
And then find the limit as n approaches infinity of that
yes, while keeping the n general
so, for any n, an/an+1 = ...
we will use the formula $a_{n} = \frac{(-1)^n}{(2n+1)!}$
rafilou2003
.close
Closed by @plush cloak
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Hi! How do I calculate this?
(without a calculator)
all of the roots are like some powers of 4 or 5
you can represent all of them in exponent form and try to see good simplifications
this is good
but this isn't
wait why does this give false?
Can you convert everything in terms of some powers of 2 and 5?
like what?
For example, (0.625)^1/3=(625/1000)^1/3=(5^4/5^3*2^3)^1/3=(5/2^3)^1/3=cbrt(5)/2
Could you write this in wa and send the picture so I can understand what's happening here?
@harsh goblet Has your question been resolved?
@harsh goblet 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.
there are 30 students in a class
the teacher asked every student in which day they were born
as in sunday, monday etc
and the year and month dont matter
what is true to say?
A/ every day of the week at least one student was born
B/ at least in one day of the eek there were born less than 3 students
C/ at least in one day of the week there were born more than 4 students
D/ in two day sof the week there were born at least 5 students
A is obviously False
i agree
WTF
💀
yea
how am i supposed to know
Distribute 30 things into 7 buckets
maybe by elimintation
You'll have at least floor(30/7) in one bucket
Yes, and that eliminates two of the options
And for B/ you can just find a distribution where it's false
how does that eliminate 2 options?
yea
how
it only eliminates A
If all students are born on Monday, then D is false too since all other days have no birthday
D would need for example 25 on Monday and 5 on Tuesday
yea ig
what is the avg distribution of students?
I practically gave you the answer
yea
Closed by @weary saffron
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Channel closed due to the original message being deleted.
If you did not intend to do this, please open a new help channel,
as this action is irreversible, and this channel may abruptly lock.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
if it is 3, how so?
bc i thought it was 5
since it says consecutive
bc like (5,6,7)
but i realised it says that AC and BC are consecutive
so 6 has nothing to do with this whole thing
nvm got it thank you
.close
Closed by @forest ridge
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
for any t(placeholder for an angle) number. sin(-t)+cos(-t)=
Cos (-t)=cos t
Do u know this
sin (-t) isn't sin t
yes
aightt
But once you're told it isn't the other three alternatives, of course you'd know which one it is...
my genius is coming back
party pooper ahh
Whatever you say, you can ignore me and close this if you think so.
Though of course, the ideal thing to do would be look at the graphs of these functions and figure out for yourself which one's even and which one's odd.
It's the other way.
Thought your genius was back.
you're funny
Jesse it's time to cook
help me man
oh I thought u had it already 
.
i do
but i need help on like
8 more of these tiny lil things
You can share them, no help without looking at the question.
soz i was
don smth
for any t number, for which there's cos=/0, we have tan(-t)=
i can't cook
nah i can't even light the gas on this
Again, if you'd just read what odd and even functions mean and their graphs, it'd be much easier.
Because it seems to me all these problems are solely focused on that.
Closed by @wind topaz
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 that actually uniquely determined
no 61 is the right answer
i just don't know how to get it
yea
What do you know about prime numbers?
ah, yeah, that tracks.
Are you sure?
This isn't right.
(5 is a factor of 5)
yeah so 1 and itself are the factors
okay
so it's a prime number
what about it
i remember my teacher going like a is 31
but i can't rememebr
You have that prime number as a product of two numbers. You also know that prime numbers only have 2 factors.
1 and 31
if two natural numbers multiply to give a prime, that could ONLY have happened if one of the numbers was 1 and the other was that prime.
so
b is
1
No?
or is it the opposite way
bro idk i'm trynna remember when my teacher said..
i think she got the answer wrong, she ended up with 31 i think
but i don't get it
.
so b is 1
no
the two numbers being multiplied aren't a and b but a and a-b
and a-b is what's equal to 1 (bc it's known to be smaller than a)
huh
it says a(a-b)=31
so a-b is supposed to be 1
yes a-b is 1 that's what i said
okay
OMG I GOT IT
SO A IS 31 AND B IS 30?
OMG YOU'RE A GENIUS
BRO I'VE BEEN STUCK ON THIS QUESTION FOR THE PAST HOUR
GOD BLESS YOUR SOUL
YOU SAVED ME
THANK YOU
.close
Closed by @gaunt birch
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) of (P10)
Why do we have this condition here?
Oh I under
Understand
a is not an element of P
.close
Closed by @eternal chasm
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Channel closed due to the original message being deleted.
If you did not intend to do this, please open a new help channel,
as this action is irreversible, and this channel may abruptly lock.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
how would i even start to solve this problem 😭
To get x_2, you need to draw the line tangent to f at x=x_1
x_2 is the intersection of this tangent and the x-axis
And you can do this again to find x_3
@eager pivot Has your question been resolved?
@eager 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.
• 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.
Dont know how to solve
are the 86º angles EDA and EBC?
sorry that's an E not a G
yeah you're right
i tried everything, I dont know how to properly solve it
okay so.
Angles:
DAE + AED + 86º = 180º
CDE + EDA = 180º
CDE + DEB + 86º + BCD = 360º
YES CHEF
you also have that on the big ass triangle:
sin86º/(x+8cm) = sinBCD/(x+5cm)