#help-4
1 messages · Page 30 of 1
Dhruv
Yes
Wait you're right
Its not 0 × infinity in the first place
I made a mistake
Thank you
Both of you
Yeah
Thank you
I thought it was 0 * infinity instead of 0 ^ inf
That's why I thought it couldn't be ignored
👍
.close
Closed by @analog schooner
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.
Closed by @river shale
Use .reopen if this was a mistake.
No, you’ve already claimed a channel
I don’t have one
I claimed this for you
Nah, it’s alr
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 am trying to make a vector that points to the direction that the point at x=1 is moving to, but it seems very off, could someone help me?
i need it for its endpoint to be $(x,i\cdot y, i\cdot z)$ where y and z are coordinates of the beginning of the vector
maxtsg
and in this case x is just 1
since desmos doesnt accept imaginary vectors i just swapped the coordinates and flipped a sign since a+bi * i = -b+ai
but it didnt work i think
@icy sigil Has your question been resolved?
Closed by @icy sigil
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.
So the test says it should be impossible, but I think x²=3-5/3x⁴-2x⁵
x³=3+2x¹-2x⁵
Am I dumb or is that the real answer?
if you have five variables and only four equations, you can't have unique solutions for the system
i.e. there are infinitely many solutions
Its general solution to the basis to the x² and x³
@lavish tinsel Has your question been resolved?
Closed by @lavish tinsel
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Hi, I neeed someone to explain me this.
i'm learning riemann sum and a teacher wrote this
If f:[a,b] -> R and P, Q partitions of [a,b], and P ⊆ Q, then
S(inferior)(f,P)=<S(inferior)*(f,Q)=<S(superior)(f, Q)=<S(superior)(f,P)
and he said it was bc if A ⊆ B, then inf(B) =< inf(A) =< Sup(A) =<Sup(B)
it doesnt get on my head bc i think the signs (=<, =>) should be inverted, and I need someone to explain me why does this work this way
Thanks
if A ⊆ B, then elements of A cannot go below more than elements of B could, because any place A reaches, B will reach too
so B is the only one that can potentially reach further down
similarly, no matter how far up A reaches, B will reach too
so B is the only set that can potentially reach further up
as a small example in terms of intervals
A = [-1,1]
B = [-2,2]
A ⊆ B
A is a box contained in B, a bigger box
the bigger box goes further down and further up
no matter how big the small box is, the bigger box must, by definition, be bigger
but then what my teacher wrote shouldnt be
s(inf)(f,Q) =<s(inf)(f, P)=<s(superior)(f,P)<=s(superior)(f,Q) ?
oh wait actually
It does work the way it's originally written
when you have a partition made up of more subsets
then each subset is individually smaller
that's how you have to interpret it
if P ⊆ Q, then take one subset in the partition P, call it B
then it's either gonna appear as is in the partition Q
or it's gonna be divided into smaller sets, call them A1,A2,...,An
the part of the inferior and superior sums for P that is linked to B will be length(B)*inf(B) and length(B)*sup(B)
whereas the terms that correspond in the partition Q will be length(A1) * ... + length(A2) * ... + ...
because inf(B) <= inf(A1), inf(B) <= inf(A2), ...
we will have length(A1) * inf(A1) + length(A2) * inf(A2) + ... >= [length(A1) + length(A2) + ...]* inf(B) = length(B) * inf(B)
same thing for superior sums
i still dont get it how does it apply for this
I'll try again
thanks
btw are partitions for you any kind of sets or are they just points that separate intervals?
sets i think
ok
what it means for $P\subseteq Q$ in terms of partitions:
If $B\in P$, then you can find $A_1,A_2,...,A_n\in Q$ such that $B = \bigcup_{k=1}^n A_k$
Raphaelisius Maximus MMIII
uhm sorry is that U a summatory?
it's a union
B is exactly the union of some subsets in the bigger partition Q
Q is a "finer" partition than P
okay
makes sense right? It should be your definition
yeah, never read it that formal but it makes sense
ok
let's focus on the inferior sums for now, superior sums will be analogous afterwards
what's your notation for "length" or volume of a set?
so I can be coherent with what you have
uh no, like [a,b] has length b-a
oh alright
what's the symbol for that length
maybe i got confused cause english isnot my first language
that's cardinality btw
and im not usually talking abt math in english so im still not used to this
what symbol do you use for this?
i dont think ive ever used a sign for that
really? how did you define inferior and superior sums then xdd
xddd
ok, but have you ever seen mathematical definition of those
like S*(f,P) = ...
anyways
I'll write $\lambda(C)$ the 'length' of set $C$
Raphaelisius Maximus MMIII
for example $\lambda([a,b]) = b-a$
Raphaelisius Maximus MMIII
are you ok with that notation?
on the superior sum is the same as inferior but instead of inf it says sup
yes
yes, but here I see this is the particular case of where partitions are intervals
I asked if this was the case
i thought sets were intervals
nevertheless, we can continue with the general case
intervals are sets
not all sets are intervals
now, for any partition $R = {x_0,...,x_n}$ of $[a,b]$, the definition of the inferior sum of $f$ on $R$ is $S_{inf}(f,R) = \sum_{k=0}^{n-1}(x_{k+1}-x_k)\inf_{[x_k,x_{k+1}]}(f)$
Raphaelisius Maximus MMIII
good?
good
Raphaelisius Maximus MMIII
yeah
so for example, if we take x_0, x_1 in P
that might become $x_0,y_0,y_1,...,y_m,x_1$ in $Q$
Raphaelisius Maximus MMIII
so I can divide $B = [x_k,x_{k+1}]$ into $A_1,A_2,...,A_m$
Raphaelisius Maximus MMIII
so while in $S_{inf}(f,P)$ we'll find the term $(x_{k+1}-x_k)\inf_{[x_k,x_{k+1}]}(f)$
Raphaelisius Maximus MMIII
in $S_{inf}(f,Q)$ it will be replaced by the terms $Length(A_1)\inf_{A_1}(f)+Length(A_2)\inf_{A_2}(f) + ...$
Raphaelisius Maximus MMIII
does that make sense?
some
ok
we can go back to this if it's still unclear
now, we'll look at those two facts
Fact n°1: $Length(A_1) + Length(A_2) + ... = Length(B) = x_{k+1}-x_k$
Raphaelisius Maximus MMIII
that's just stringing up every "small" subset back together, it makes the big set again
Fact n°2: since $B$ is a bigger set than $A_1,A_2,...$, then $\inf_B (f) \leq \inf_{A_1}(f)$, as well as $\inf_B (f) \leq \inf_{A_2}(f)$, etc.
Raphaelisius Maximus MMIII
so
$Length(A_1)\inf_{A_1}(f)+Length(A_2)\inf_{A_2}(f) + ... \geq Length(A_1)\inf_{B}(f)+Length(A_2)\inf_{B}(f) + ...$
Raphaelisius Maximus MMIII
that's exactly $Length(A_1)\inf_{A_1}(f)+Length(A_2)\inf_{A_2}(f) + ... \geq Length(B)\inf_{B}(f)$
Raphaelisius Maximus MMIII
so everytime we replace a term in this inferior sum P
by those terms in this inferior sum Q
we effectively get something larger than before
adding up larger stuff will result in a larger total
so $S_{inf}(f,Q)$ is larger than $S_{inf}(f,P)$
Raphaelisius Maximus MMIII
$S_{inf}(f,P)\leq S_{inf}(f,Q)$, what was expected
Raphaelisius Maximus MMIII
does this happen bc inf(f,b) =< inf(f,a)?
yes
is P,Q here a subset of [a,b]?
in the context I think they're both of the form ${x_0,x_1,...,x_n}$ where $a = x_0 < ... < x_n = b$
Raphaelisius Maximus MMIII
i think i understood the reasoning, but i still cant get my head around this
here is a graph of the area S_inf(f, P) we are calculating for a function (in red) and a partition P (in green). And here is the graph of the area for a refinement Q: S_\inf(f,Q)
you can sort of see why S_inf(f,Q) would be larger
yeah
intuitively, refinement -> S_inf and S_sup gets closer to the actual "area" of the function
so it is natural to expect S_inf and S_sup to get closer for Q than for P
yes
but i still dont get why S_inf(f,P)=< S_inf(f, Q)
i can only see it the other way around, since Q is larger than P
didn't the graph gave you a example where you can see S_int(f,P)=<S_inf(f,Q)?
only the = part
you can't see why thry might be equal?
cuz the example I gave: purple >green
P={0, 0.5, 1} and Q={0, 0.2, 0.5, 0.8, 1}
sorry, i dont get where S_inf(f,P)< S_inf(f, Q)
here is the partition Q marked in orange
and the partition P
green area represents S_inf(f,P) and purple represents S_inf(f,Q)
oh yes I think I got it now
extra values is really giving it an extra chance to take higher values than the current infimum
so is S_inf(f,P)< S_inf(f, Q) because A(S_inf(f,P))<A(S_inf(f,Q))?
well S_inf(f,P) is precisely the area
ie S_inf(f,P)=A(S_inf(f,P))
because if you check your formula it is "length times height" over all the rectangles in your partition
thank u so much
np
thank u both
and you can see why sup is smaller right?
i got it now i could kiss ur brains
kind of the same thing right_
?}
yeah
extra values-> extra chance for the supremum to be smaller
if you get what i mean
since Q is more precise, it wont be so far away from the function, so its area wont be so large
THANKS
finer the partition, closer to the area
sup is over estimation, and inf is underestimation
Closed by @cedar spear
Use .reopen if this was a mistake.
u too
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.
integral e^3x times sinx dx
needs IBP I think, wanna use DI method but idk
Are you familiar with the horse shoe method? Indeed, that method comes from the DI method.
nah, what is it?
So do the first two steps of the DI method, and you'll notice that you kind of end back where you started. That allows you to have a relation with some fudge factor, which is the solution.
huh
I know this
for DI method, you go until 0, until row is integrable, or you end up at the same spot as you started excluding the signs for that row
I don't think you ever end up where you started with this problem
It won’t go to 0 here
yeah that part is clear
But it’ll repeat
Yes, that's what I meant when I said kind of. Your second case is relevant.
how?
e^3x will just continue 1/3e^3x 1/9e^3x etc
so ur never gonna end up back at e^3x
But you can factor out the fraction.
ah
okay so ig you end up with
$$
\frac{\sin x}{3} e^{3x} - \frac{\cos x}{9} e^{3x} - - \int \frac{\sin x}{27} e^{3x} , dx
$$
I think
Paul04
/27? 
is it right and I just needa factor out?
Without checking if the math is right, you would have that whole expression equal to the original integral. So combine the two integrals (bring that one to the other side) and you'll have the solution.
You should but I got /9 inside the integral?
OH
you gotta use the row 🤦♂️
not the diaganol
right?
ignore the stuff on the right
For the last step if the DI method isn't zero'd, yes you have to use the row rather than the diagonal.
So you seemed to have done a step too many, sorry soldier.
yeah
so how should I move it over I ended up with 1/9 * the integral
Bring the 1/9 to the other side.
yeah
Also you should have a 1+1/9 then, no?
uh
Since the original integral plus the 1/9 * integral, so that's (1+1/9) * integral, unless that's what you meant.
on the right side?
So you moved the 1/9 * integral to the left side, which already had 1 * integral
So that's 1/9 * integral + 1 * integral = (1/9 + 1) * integral
Then you can bring that (1/9 + 1) to the left side that you drew, so now you have just the integral in the right side == the solution.
yeah idk where the +1 is coming from
moving the integral out is just doing 1 * 1/9 no?
So you have "... - (1/9) * F(x) = F(x)", which becomes "... = (1/9) * F(x) + F(x)", agreed?
where F(x) is the original integral, for easy notation.
oh ur moving it over
why is 1/9 pos on the right side tho
is my double negative = pos wrong?
Well to bring a left negative to the right, you have to add both sides by its positive.
well yeah but the 1/9 is pos unless I screwed smth up
a - b = c ==> a = b + c
yeah yeah fs but 1/9 is pos on my end look at the pic
Oh I see what you meant,
I went off integral udv = uv - integral vdu
and the row had -sin
so I thought the - from the formula with the - from the sin would make pos
but idk
When you do row multiplication, you have + -sin(x) * (1/9) * exp(3x), so it should be negative.
yeah, but what about the - integral part from IBP formula
maybe I'm thinking of this all wrong, sorry if that's the case
I'm not sure what you mean by the IBP formula. IBP == initial boundary problem?
integration by parts
it's DI method essentially
ok so ur saying it's neg let's just go with that forget what I said
so we end up with 10/9 integral
then move that over to the left and it's gg?
right
okay so lemme see ig final answer is
$$
\frac{9}{10} \left( \frac{\sin^3 x e^3x}{3} - \frac{\cos x , e^{3x}}{9} \right)
$$
Btw, any particular reason you integrated the exponential instead of the other way? Should yield the same either way.
Paul04
LIATE says trig before exponential
for u
What is LIATE? I fear that's another region-dependent concept.
Interesting, thank you.
$$\frac9{10}\left(\frac13\sin(x)-\frac19\cos(x)\right)\exp(3x)+C$$
Ordinary
Np, and if you ever want to verify Desmos is a quick and dirty way.
wdym?
One moment as I verify this actually..
Desmos is a free, light-weight website for graphing.
yeah
Yep, it's good. It looked weird for me for a moment, sorry about that.
Yeah, shortens IBP quite a bit, nice notation
can you send a ss of how you checked
like what u did
Nothing special, I just graphed it.
Oops, replied to the wrong message.
oh I see, tysm!
I'll try that next time around. thanks again for the help!
.close
Closed by @cosmic crest
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• 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
$\sqrt-1 = i$ ?
e4 e5 Qh5 Nc6 Bc4 Nf6 Qxf7#
Like how pi = 3.1415...
Ohh i thought Negative - 1 came from the square root of 19
But i remember my teacher squaring the negative number then simplified it
How u do that
19 for example
I honestly forgot, should have taken notes
Let’s make things clear, the determinant only decides the status of a quadratic function’s root.
mathematicians wanted solutions to $x^2+b=0, b>0$ so they named $i$ as a number that has the property that $i^2=-1$ 🤔
$\sqrt{-1}$ \underline{is} $i$
i think the actual definition for it is i^2=-1 rather than i =sqrt(-1)
Then i and -i would be ambiguous.
Why
but I see what you mean, like when we make adjoints R[i]/<i^2+1>
Since if the definition was i^2=1, then -i also satisfies that so then -i = i.
3^2 = 9
(-3)^2 = 9
3 = -3
Doesn’t make sense at all
There's a difference between satisfying, and being defined (precisely) as heh
It's taken to be the principal, of course.
Closed by @gaunt fog
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 in algebra 2 rn doing logorithms how would i go about solving this question
Do you remember what the difference between "f(x)" and "f(x + a) + b" is? (recall shifts)
yea
Could you explain what the difference between what "a" does, versus what "b" does?
b is vertical shift and a is horizontal
so
b movees
up and down
a left and right
Exactly,
So we want to move the blue curve to the left (by how many units?), and up (by some amount)
Close, we now need to express g(x) as a function of f(x) (so plugging in for a and b into f(x-a)+b)
.
g(x) = log(x +1 ) +4?
Yeah, that's it.
Closed by @neat crag
Use .reopen if this was a mistake.
!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).
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 once again need some help with pdes
The question is to solve u_x + u_y + u = 0, and how I might solve this via method of characteristics
The problem is that I don’t really get what the goal is for picking a suitable coordinate transform is, and how I might go about picking it
@pine prairie Has your question been resolved?
@pine prairie Has your question been resolved?
-# i think you can ping helpers if you want
-# it's already 15 mins
-# gl i havent learnt pdes
@pine prairie Has your question been resolved?
the idea for method of characteristics is as follows
we want to pick a suitable coordinate transformation such that our pde turns into an ode
recall by the multivariate chain rule that if we have a coordinate t=t(x, y)
then du/dt = du/dx dx/dt + du/dy dy/dt
here we want that to look like u_x + u_y
so we wanna try smth like dy/dx = 1 if that made sense
How do we know this exists
i mean if you have a pde of the form function * u_x + function * u_y
then it kinda looks like that
@pine prairie Has your question been resolved?
lol long time
iirc, you just pick a convenient transformation and it's okay as long as the determinant of the Jacobian is non-zero.
So worked out, this is what I find.
It's what I was taught, the answer is "because it's simple, and it works".
As long as the determinant is non-zero. This doesn't guarantee that you'll simplify the problem.
It's subjective, and all about simplifying the original problem (like what the guy said earlier about turning the PDE into an ODE, like what I did above).
What’s the choose c = -d = 1 step what are we doing there
In this case, because the problem you gave was quite linear, it works perfectly. If you did something nonlinear like f(x,y)u_x+u_x^2u_y+u=0, linear wouldn't work.
We have the general form of the linear change of basis, so now we "eyeball" it to make it into an ODE.
So I chose those values to cancel out the partial beta terms and make the partial alpha terms add to unity.
I mean any non 0 det matrix will be a bijection and hence a valid change of basis
Why
Indeed, but sometimes one'd accidently choose a too good change of basis that'd "simplify" everything but give a determinant of zero so it'd be worthless and wouldn't give a proper solution. So it's mandatory to check the determinant.
Because
It's all about reducing the dimensions, which is doable because it's linear.
You could alternatively choose to cancel alpha and put beta to unity, you will get the same answer. Otherwise you did something wrong.
(alpha terms, and beta terms)*
@pine prairie Has your question been resolved?
i really need help guys, im having a test tmr
supposedly speaking if i had two planes that were perpendiculared on the same line, would the distance between the two opposite apexes to the two opposite planes equal each other
english is not my first language so this could be a little hard to understand
hopefully you guys can help me
!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).
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.
Help
Drawing the flow chart only
@minor socket
!noping
Please do not ping individual helpers unprompted.
doesn't matter go dm him not in a helper's channel
stop spamming OP's channel
Agreed but don't inconvenience others
They aren't a helper,idk their role but shoo.
@worldly shuttle Has your question been resolved?
@worldly shuttle 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.
waitm thats possible?! i suddenly have a reason to learn lambda calculus
i actually did do that but someone just somehow guessed a functioning tetration function that works better than mine (bc mine contains a pred function and i dont know how to express pred) but is structured extremely similarly to mine
so we figured out 2 things that work
im only barely know that lambda calculus can write stuff in a weird way, so i dont understand any of what you did
but, does it make tetration easier to solve, or just translate it to a physical form?
can someone explain function
based
do you need help with a question?
it dont make it easier imo its just fun
if you know how to do anything in lambda you can be handed a huge equasion and solve it without knowing whats happening
bc simplifying/solving it is always the same step
ok soooooo
the text form translates to the diagrams
say i have this function
λG.G
like plus or times
λv.v is a function
doesnt matter what letter it is
then we have the input, lets say its BANANA instead of a number
λv. says "OKAY, find all instances of v, and replace it with the input"
so λv.v banana = banana
THATS LITERALLY IT
@hushed kayak you following?
you can make more complicated equasions to do more complicated things
λF.F is just the simplest
say um
λx.λy.λz. x (y z)
is a times function
so say i want 5x3
λx.λy.λz. x (y z) 5 3
5 being the first input, and 3 as the second
you replace x with 5, and then replace y with 3, and then simplify more but that requires knowing how to express numbers in lambda and i didnt explain that
the drawings make a lot more sense
you gotta mention also that numbers and true/false take on something weird for lambda calculus
for lambda calculus, everything should ultimately just be in lambdas, so numbers are really some specific lambdas in disguise
i dont know what youre tryna say im just tryna give a basic explanation
that doesnt give me a nice way to follow up
thats a bit hostile, you dont have to say things like that
lets not point things towards me this fast
so the multiplication from earlier would give you 5 (3 z)
now if the multiplication works out, 5 (3 z) should be 15 z
to see how that happens, you can view numbers as the "number of times you apply a function"
so if you try doing 3 f x, the result is f f f x, or the result of applying f to x three times
no actually you need the () to specify whats going into what
bc f f f x ≠ f (f (f x))
by default, you dont need to, parentheses weirdly go right-to-left
you expressed function f with 3 inputs
so f f f x defaults to f (f (f x)) instead of ((f f) f) x
youre very wrong
and id appreciate it if you would stop inserting yourself into my affairs
nicole this question isnt specifically about you, its about me adding to an explanation on lambda calculus with more details
if someone did this to me, I would assume they are elaborating
(function) 5 4 6 2
is the function with 4 inputs
the () changes things
Ive checked and yea, by default its left-to-right
the post I took this from left the parentheses out, got it mixed with function composition
its not( 5 of 4 6 2), put into function
this has nothing to do with fucking left to right
oh my god this is so badic
I understand what youre talking about, but I dont see the use of phrasing this and then presumably directing it towards me
I mixed up one thing with another, they shouldnt be mixed up
ok now for true/false
the interesting part here is that true is "take in 2 inputs, then output the first"
and false is "take in 2 inputs, then output the last"
they dont act like the usual true/false
i suddenly dont regret doing computer science
these are two completely fucking different equasions
nicole I am aware that you watched the same video I do
ive done far more than watch the video
Ive made an egregious error, but after this its not necessary to tell me the same information again
I didnt imply youve only watched the video, just that the video is very good
well i dont see you having acknowledged that before this message and if you did i dont recognize it
im
thats alright, we can move on from this
the message may have been buried, but its here
function composition acts right-to-left, so I mixed them up, is what this message means
im sorry its just i see someone doing something that ammounts to 1+5 = 5 and ive had 4 shots of coffee and like no food
its alright, it happens to me just as easily
Ive been in your position several times and did not calm down
the important thing for me to see is to think: dont attribute it to malice, attribute it to a typo
in this case its a pretty strong typo and Im honestly not happy with having made a mistake like that
and the sqrt5 equasion isnt fun anymore bc of you so thers that going on and you intervene to me explaining this telling me im not doing it right while doing this and now im like a pissed twitter black supremacist getting pissed that someone said hi
its just that theres effective and ineffective approaches
im not mad at you over this anymore bc its been cleared up
and from my perspective, Ive seen that kind of approach enough to know it wont lead you to anywhere fruitful
Im sorry nicole
number theory questions cannot be answered with continuous algebra, until you get to complex analysis
even then I have no idea how they pull it off
until then, we have modular arithmetic and diagonalizing matrices to justify particular behaviors, enough to answer the question
idk what that means but okay
@hushed kayak im sorry
continuous algebra?
you dont have to get into that, we can focus back on the lambda calculus
explaining the false and true function is important tho simply bc its confusing and the main resource for lambda does a garbage job at it
its really simple tho
yea, have you seen an if statement? it looks like this
just misleading
im trying to find a formula for continuous tetration, so i probably wont get much out of this, will I?
continuous? theres many sources about attempting this
is it "if a then b"
how does if work
its more of "if P, then A, else B"
i can just give you the 2 equasions we found
what a true does is select A
and what a false does is select B
well tetration funtions
they work on fractional heights?
yep, thats the idea
??
2^^1.5
idk how to express a fraction in lambda nor if it can be done but probs not
it would
do that
perfectly
but idk if the expression of fractions is possible
and at least, lambda calculus isnt going to help you out for these sort of continuous functions
lambda calculus is more for showing that yes, its possible
its just not very convenient
so the number 30 is huge
111111111111111111111111111111
tetration in lambda is too much paper to be practical
here ill show
for reference, division alone is messy
have not seen
@hushed kayak
this is partioally why lambda isnmt helpful for tetration
still cool
that and itl take longer to do the steps
and also to consider fractions and somehow implement that
yea idk i think its too objective and solid to have fractions be a thing
but i know not
too low-level is the usual phrase
there are other approaches than lambda calculus to create a continuous tetration function
granted, you should also learn lambda calculus too regardless
low-level for "the parts you are given are too basic, too small to make something of this complexity without grouping things together"
theres a research paper on a tetration function, I can try and find it
i mean we are working with the physsical manifestation of the concept of the number 1 soooo
i didnt know ppl had solved for one before
i mean makes sense duh
but yea
I remember the paper, theres a picture of them generalizing it to complex numbers
at least I remember the graph
might be this one http://myweb.astate.edu/wpaulsen/tetration2.pdf
not very readable
the general idea is that you can consider a specific tetration function F(z) = b^^z
F(z + 1) would be including one b in the "power tower" so thats the same as b^F(z)
ive found ppls note sheets online that contain functions
and ive never found a function that gives a smaller output that actually worked to any capacity
i know that they dont usually work with small numbers, im speaking in spite of that
using F(z + 1) = b^F(z), they use something called "complex analysis" to work out details about this F(z), which by default will work for most real or complex numbers z
I think I know what this table can tell you
this is from the paper, and from their guess at a continuous tetration function
the upper-right table for example lists 2^^0, 2^^0.1, 2^^0.2, ..., 2^^1
similarly for the 3/2, e, and 10 tables
they admit their approach will not work if the base is < e^(1/e) which is about 1.445
@hushed kayak 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 unbiased estimates be decimals
unbiased estimate of population mean
yes of course? why couldn't they
the population mean of whatever quantity can be a decimal even if individual observations of it are only integer-valued
oh ok tysm i js thot population would mean counting people but we cant half a person lol
if you randomly toggled or not toggled a light then looked on it, the average brightness is between dark and lit
you can estimate this average and itll also be between dark and lit
doesnt necessarily mean how bright that average is means anything concrete, youd have to be more abstract about it
ohh alrights thank u
whats the difference betw sample mean and population mean? or can it be the same thing
calculating the mean across the entire population is pretty hard, youd need to ask everyone so that you can get their values to average
because of this, you only choose a random portion of them for a sample, for the easier-to-calculate sample mean
if you did multiple samples, the means you get would cluster around the population mean
this makes the sample mean an unbiased estimator of the population mean: the average sample mean is the population mean
the difference is that one of them is feasible and the other one isnt
the sample mean being an unbiased estimator means the sample mean aims to be the same thing as the population mean
@willow arch Has your question been resolved?
okk thank u so much!
Closed by @willow arch
Use .reopen if this was a mistake.
np
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Maa chudao
Parhai kartey bhi ho Tum sab
?
uhh, do you have a question? 
@ivory bough Has your question been resolved?
💀
Tameez mein rho chutiye
He is js insulting us
Closed by @next vortex
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.
<@&268886789983436800>
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.
is it possible to transform this ODE to a diophantine equation? for instance euler's method time discretiton
@split edge Has your question been resolved?
@split edge Has your question been resolved?
@split edge why specifically a diophantine equation?
because you have 4n/5 in the exponent, if you can you will be very restricted by what values of n are possible if you insist on integer solutions.
@split edge 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.
if i have a A=>B with perhaps steps in between and i know for certain A is true and from that following B is also true. in that case is it always true to also say B=>A?
if i have a A=>B with perhaps steps in between and i know for certain A is true and from that following B is also true. in that case is it always true to also say B=>A?
What does that mean
Also, if A is always true, then B => A is true regardless of what B is
i mean that i have proven that A=>B is true#
okay so im right, right? so in that case could i have written <=> all along instead of => for the proof A=>B from the beginning or do i have to prove B=>A even tho we know its true given what we just discussed
If A => B and A is always true then A <=> B
But if A is always true and A => B then B is always true
so i only use that => arrow when i dont know what i start with is for certain true or even false?
A => B is just some operation on 2 statements
okay thanks
maybe a small rephrasing helps. if we know that A is always true, then any statement C=>A is true, no matter what C is. in particular those statements are kinda irrelevant
"If I have 5 apples, then the color blue is blue"
as an example
okay, but are there proofs in math where u show that A<=>B is true? in that case u would only need to show that for certain A is true and B is true in A=>B, right?
you show that if A is true then B is true
and if B is true then A is true
if you want to show that A <=> B
you have to show both A => B and B => A
just doing one direction is not enough
i cant skip this?
no
but does A=>B imply B=>A if we know for certain both A and B are true?
Then you’re here
if both statements are true then yeah but theres no use for that really
if we know that both B and A are true
okay so there will be no question like that to begin with, i see. thanks yall
the color blue is blue implies that 2 is even
and 2 is even implies that the colour blue is blue
but who cares
I mean it’s a statement that’s always true
It’s a valid statement
It’s just not often useful
tautology strikes again
thanks!
!done, I assume
If you are done with this channel, please mark your problem as solved by typing .close
@raven frigate Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
I do not want an answer but some kind of hint on where to start with this question. This question is in the series, sequences, and binomial theorem part of my curriculum.
try to figure out the lengths of OB_1, OB_2, ...
Whats the difference between each arc? Like is there a set difference in distance from the center
Oh nvm
Closed by @buoyant sluice
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
which number
take the derivative of that right expression
Ok you will get $8k^7 -16 k^3$
oh wait sorry dont differentiate yet
playboi69
take k^4=a
Alr
so now u have a quadratic in a
Ye
RHS is a quadratic in k^4
Ye
-D/4a
yes
It's -1/2 for this one I think
oh but that quadratic has complex roots
I meant 1/2
Ye you are right
do u understand or are u just agreeing
what about statement 2?
Except drawing a rough graph of the quadratic
yes you should get a good idea what ur supposed to do based on statement 2
So what am I supposed to do now
figure out if statement 2 is true or false
let me remind you of function transformations then
start from sin(x)
then sin(3/2 * x) is a horizontal compression
with scale factor 3/2
Ye but there is y inside cos
it's the same reasoning for cos
No I meant the variable y
f(y) = cos(5y/3), y is a dummy variable
f(t) = cos(5t/3)
f(x) = cos(5x/3)
these are all the same function
Ye true but what this all means sin has a different variable
Cos has a different variable
And they are multiplied together
Unless x = y
the question states that $x, y \in \mathbb R$
so $x, y$ are being treated as the domains of $\sin, \cos$
south
what's the range of sin(3x/2) then, if you've managed to draw it?
The range will be -1,1 for any sim function
Sin
Unless there is a restriction of domain
yep!
In our case there is none
and the exact same is true for cos as well, right?
Ye
yeah okay then statement 2 is true
Ye
okay now, what's the absolute maximum of sin(3x/2) * cos(5y/3)?
based on multiplying them together as you said
I have no idea
well, you know that sin(3x/2) <= 1 for all real x
Yea
well and you can assume that cos(5y/3) will be positive, since we want the maximum value
so multiplying gives sin(3x/2) cos(5y/3) <= cos(5y/3)
Huh
multiply both sides by cos(5y/3)
well then you've already found the max of cos(5y/3)
the goal is to now check statement 1 ofc
Ye
it's like if I have p(x) whose range is 0 to 10
and if I have q(x) whose range is from 11 to 100
I can conclude that p(x) and q(x) never intersect
Ye
you only need to check that 10 < 11 in that situation
Ye just the range
okay so now
what's the maximum of sin(3x/2) * cos(5y/3)?
Cos 5y/3
and what's the maximum of that?
yes
yeah if that's easier for you, I see now
it's a number
so it's neither of those
Ic
sin 3x/2 cos 5y/3 <= sin 3x/2 <= what number?
okay!
yeah actually if sin(3x/2) = -1 and cos(5y/3) = -1
you also get - 1 * -1 = 1 as the maximum, so
Yee
the negative numbers also worked out here
okay do you recall what the minimum of k^8 - 4k^4 + 5 was?
Yea won't it cause problems
They both are equal to 1
yes if we had -2 < f(x) < 1 and -3 < g(x) < 1, we'd get max f(x) * g(x) = 6 instead, just to clarify
yep!
okay so we're nearly done actually
it seems pretty obvious, but the important thing is that one value of x satisfies x^2 - 4x + 5 = 1
-1
now at the start, we set k^4 = x
I meant 2
oh yeah we also need that the x-coordinate of the quadratic vertex is 2
so k^4 = 2, that has 2 solutions
k^4 = -1, well that has 0 real solutions, completely different story
indeed
2 or 4?
take the 4th root of both sides
that's the same thing as square rooting both sides, and then square rooting again
but you can't square root a negative number in the reals
so like k^2 = -sqrt(2)
that has no solutions
we just have k^2 = sqrt(2)
2 solutions
Ic
in general the (odd number)th root will give 1 sol
(even number)th root will give 2 sols
Alr
Oh damm I've never seen this type of question tho
Closed by @harsh jolt
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 chance that someone could explain this theorem and the subsequent proof? I’m confused on the definition of an orbital and how n-m is obtained
do you know what the representation of a permutation as a product of disjoint cycles is?
Yes, I do
if I have a cycle (13562), can you write that as a product of 4 transpositions?
(1 2)(1 6)(1 5)(1 3)
so for a permutation like (142)(35)(768) on n=8 with m=3 cycles, can you write it with 5 transpositions?
well the point being that you write each individual cycle as a product of transpositions
for each cycle you need one less transposition than the lenght of the cycle
so if you have m cycles then you need n-m transpositions
which really is just the statement of the theorem
Got it now, I couldn't see the pattern, nor the fact that orbitals is another word for cycles. Hours upon hours of studying and foggy brain! Thank you for your help!
Closed by @tranquil crane
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.
playboi69
$cosec^2(\frac{\pi}{2}(a+x))\in [1,\infty)$
playboi69
uh
Wait a second
it's a^2+2a
yes
yup
a=-1 you mean
A= 1 for the quad to give -1
No nvm -1
Ye so where did I go wrong here?
,rccw
okay so you want to solve $1= cosec^2(\frac{π}{2} + \frac{ πx}{2})$
wai
can you silve this
playboi69
Closed by @harsh jolt
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 questions regarding this. Not only solving but i want to know the rules like i have some quries in mind
Helllo anyone here
Hello, You just wait for the people 
Oh okay
Do you know how integrals work ?
Yeah?
Yes i do. But the thing is i ended up with y^3/3 . a root 2.
But this is wrong. Just to be clear i'm first time encountering double integrals and triple. So yes i'm finding it hard
- Can i just swap the limits like inner limits to outer and outer to inner? and also swap dx, and dy? and then solve? Because there is no way to plot the region because how the function and its limits aare given.
- is the question wrong?
i think the question might be wrong
currently the answer depends on y
can you try replacing the upper bound of the inner integral with a and see if that gives you the right answer?
Yes but it wont make any difference in getting that "Pi" in the answer.. it will just simplify it like make it concise
Can i just swap the limits like inner limits to outer and outer to inner? and also swap dx, and dy? and then solve? Because there is no way to plot the region because how the function and its limits aare given.???
Does this work? Or do i need to redefine the limits? like in each case.
in this case you should be able to swap the integrals yes
but there's something up with the question, you should probably ask whoever gave it to you to confirm if it's correct
Oh but wait doesnt it violate the rules? Like the ai said
the inner integral doesn't depend on x
so you can just move it out like you would with any other constant
and then move the other integral inside, because it doesn't depend on y
Bro
After we integrate the first one
We can move it out as a constant?
Cuz it has no relation or isn't a function of x
yep
I did that but it doesnt result in answer
yeah the question is almost definitely wrong
Wait so i can just swap the dx before and put dy behind and integrate the Y^2 respective to x?
Just take 1 as a in multiply of Y^2 and get the integration "x" and the consider y^2 as constant 😭 DONT JUDGE ME I HAVE JUST STARTED LEARNING THIS..
I'm not lol
I'm also dumb
😭😭
I'm so sorry i didn't mean anything like that
😭 YOU ARE LITERALLY BENZENE TEACHING ME MATHS. Pls i really want help. and look this is what my teacher said
🙂
Change the order of integration
Yes thats very helpful
does this make sense?
Idk what that is either
Oh wait
every operation in this image is just moving constants in/out
Woah. Wait this kind does lemme try
the thing you ended up with here is correct, there's something wrong with either the question or the answer key
Exactly
I'm getting that too
I'm confused
Is it possible the answer key is wrong?
To the guy who sent this
i'm pretty sure the issue is that the "y" in the upper limit of the inner integral should be replaced with something else
Some constant limit
Instead of just y
Could've been a typo
Mr. Muffin please ask your teacher da
Yesss she provided me some material saying go through this. and then solve. So okay no worries. I will do it Thakn you so much for trying t o help mee
Bro
Send me also
Yess
Please😭
What material do you want? like what are you specifically studying
12th
Whatever you're doing
Because I'm interested to see
But you dont get to do Double integrals in 12th
Doesn't matter