#help-39
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is what i was going for 
say x = ln t we have $\frac{dx}{dt}=\frac{1}{t}$
$\frac{dy}{dt} = \frac{dy}{dx} \cdot \frac{dx}{dt}$
Nyxzore
i saw that
but we dont know dy/dx
Nyxzore
oh I get it now

thank you so much
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one more question how do we deal with y
no derivative no chain rule
y just stays the same 
y is in t we want to make it in x as in y(x)
isnt that what the question wants?
holothink
abuse of notation at its finest just writing y fr
well i mean lets say you have y(t)
now you just have y(e^x)
then rewrite this as Y(x)=y(e^x)
but then you have to ignore my chainrule nonsense

ok
What?
Now use that do derive y''(t) as well
the issue is we have ...-y(t)=0
wdym
You have to express the equation in terms of dy/dx and d²y/dx²
y(t) becomes y(e^x) which by abuse of notation is just y(x)
technically speaking y(e^x)=f(x) some other function
.
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say for example if I have a smooth curve, then any paranetrization of that curve is regular?
or is it like the opposite, if I have a regular parametrization of a curve then that curve is smooth
You can have r(t)=(t²,t²) which represents y=x but r'(0)=(0,0)
so its not regular
what about r(t) = (t, t)
say is a regular paramitisation $P(t)=(x(t),y(t))$ as star showed if the deritive is 0,0 somewhere it is not regular so we know the derivitive is non zero everywhere. so if we take some t=c and $x(c)=0 => y(c)\neq 0$
Nyxzore
i mean thats fine
but star showed a disprove by counterexample on your first statement
oh right, r'(t) = (1,1)
so clue where to go from here

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Hello, I was given this question to show that the limit exists. Although I'm having trouble with bounding the denominator. To be very honest our professor always uses the reverse triangle inequality to bound that, but I've always been confused by the initial assumption we make. Any tips?
Suppose $\delta \leq 0.1$ or something and use that to bound $x$, then the denominator
Civil Service Pigeon
Would 1 work or 0.1 is safer?
Try it
$-0.5$ satisfies $|x+1|<1$ but not $-2<|x|<0$. Why is there a $|x|$ there anyway?
Civil Service Pigeon
Problem I had with using 0.5 was I had this
The lower bound of $-\delta$ is redundant because absolute values are non-negative
Civil Service Pigeon
I assume that’s messing you up
Yeah.....been my issue since the start of the course really
Okay then from what we have, that doesn't look right....
@quasi depot Has your question been resolved?
<@&286206848099549185>
cant read the whole chat ... do u just need help for this range inequality?
Yes, I'm trying to bound the denominator
first of all mod of x + 1 cant lie between -1.5 and zero
I didn't write that though
range of x should between-1.5 and -0.5 for this
@quasi depot Has your question been resolved?
Really?
do you need help
@quasi depot ok to show this you don't have to use numerical approximations
You just need to show the existence of delta
You can notice that X^2-2=(X-√2)(X+√2)
And |x+1|≤|x-1|+2
Or bruh
This is a false statement
It is not 1 it is 3
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hi, could anyone give me a hint of where to begin? I'm kinda clueless on this problem. Thanks
are you familiar with modulo
Use Chinese remainder theorem
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i'll have a think for a while i'll come back if i need more help, thanks
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[ 3. \text{ For each } n \in \mathbb{N}, \text{ find the possible values of } (3n^4 + 2n^3 - n + 1 : 3n^2 - 1). ] [ \text{ Provide an example for each value found.}]
Renato
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did i do it correctly? 🙏
Hummm you seem to have gone from 1-sin(theta) in the denominator to cos^2(theta)?
Amongst other things
for these establishing identity problems you should not be moving things from one side to the other
i think you tried doing that in step 2
oh
The identity is $1-\sin^\textcolor{red}{2}}(\theta) = \cos^2(\theta)$ for reference
Azyrashacorki
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^^
Yes you have mistaken it with Pythagoras identity
oh mb forgot it has to be squared for pytha theoreom
i think i got lost somewhat
Why are you multiplying 1-sinx/1-sinx
i thought getting the conjugate of one of the sides would give something
1-sinx conjugate is?
oh
right
oh shit
i think i got it
so conjugate is mainly for using difference of square right
yup
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How did I go wrong for 2
,rccw
is that 2/7 on the right?
Yea
why is it 2/7?
Crap was I supposed to subtract it
indeed.
Is this now correct? Also 4
,rccw
,calc ln(5/3)
The following error occured while calculating:
Error: Undefined function ln
,w ln(5/3)
I recommend prefacing decimals less than 1 with a 0 anyway. it was a little hard for me to see the decimal point through the half-erased writing.
and is the fourth digit there a 6 or an 8?
then it is correct.
I'll take a look at 4) now.
- is also correct minus the small nitpick I have about writing your multiplication on both sides under the equation/step (I would have preferred it written to the side).
but that's just a personal nitpick, so it's a pass.
Kk
Sorry for the rapid fire questions but for 1-18 am I just like switching the expressions
you can think of it that way if it helps you, yes.
Like this? And how would I find the decimal for 5?
,rccw
hint: rewrite 25 as a power of 5, and rewrite the cube root as an exponent.
for 2), yes.
I’m not really sure how
25 = 5^?
How did you get rid of the root 3 tho
put it aside for the time being. we'll bring it back in in a bit.
in fact we'll bring it back in when you get this one.
It’s just 5 squared right so 2
correct.
so now we have a cube root over it.
do you recall what exponent a cube root corresponds to?
hint: a square root is the same as an exponent of 1/2.
So would it be 5/3?
1/3, not 5/3.
so a cube root is the same as an exponent of 1/3.
we can now use these two pieces of information to write the argument of the log using just exponents and a base of 5.
can you do it? (hint: recall that $(a^b)^c = a^{bc}$.)
Yukari
correct!
now merge the two exponents using the rule here.
(which is called the power rule of exponents, in case you need a name to search it up later.)
2/5?
you mean $5^{\frac25}$?
Yukari
Yea
Wait 5^2•1/3
if you meant $5^{2 \cdot \frac13}$, that's right.
Yukari
so what will that end up becoming?
5^2/3?
absolutely correct.
so now you have $\log_5(5^{\frac23})$. can you continue from here?
Yukari
Wouldent I just stop there since I rewrote into the other expression and found x
oh yes, of course.
I was just going by your previous method and making it explicit if you want to.
but if you recognize this form and can stop here, then yes, this is good enough.
For this one how do I get rhe -4 to be postive since I can’t find a solution if it is negative?
is that $\ln(e^{-4})$?
Yukari
if it is, you already have the answer.
I think
then you have the answer already.
No solution right
no solution?
there is a solution.
Yukari
the only things that cannot be negative are the base and the value of the argument.
but e^-4 is not negative.
Kk and sorry I got even more questions for 12 I’m not sure how to contuine and for 18 I don’t even know how to stat
for 12, recall how we handled the cube root earlier? the same strategy applies.
the same strategy for 12 kills 18 as well.
Yea I tried doing that for 12 but I don’t know how to find 10^x=SR1000
I think mainly for 18 the form is confusing me
convert the square root into an exponent, and convert 1000 into a power of 10, like you did with the earlier problem.
oh, and don't forget to take into account that the sq. root is in the denominator this time round.
What would I do after this?
you're more or less correct, except you forgot to account for the fact that the square root is in the denom of the fraction.
I thought I got rid of the square root when I made it squared?
I mean getting a fraction of 3/2 as your exponent is correct. but the sign of that exponent is wrong.
Sorry I’m confused what you mean 😭
if I asked you to write 1/a using exponents, what would the exponent on a be?
equivalently, $\frac1{a} = a^?$
Yukari
A^2?
1/a = a^2?
hm, if we let a = 3, you're saying 1/3 = 9.
I'll spoil the surprise then, but you should review your exponents after this. $\frac1{a} = a^{-1}$.
Yukari
likewise, $\frac1{a^b} = a^{-b}$.
Yukari
so $\frac1{\sqrt{1000}} = \frac1{10^{\frac32}} = 10^?$
Yukari
How would I add that to the other expoinets just by adding a - ?
what do you mean?
Like would it be 10^-3/2
absolutely.
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For this one we have to find the domain of the graph and match it with its graph. And im having trouble figuring out the domain
Since I don’t know the original domain
Do you know where is log defined?
yea like I have these two graphs but I don’t know if that is still true for log10(x) like tiny 10
Yes
The more you increase the base of log the graph become less steeper
Ya
It depends on the argument
Log base 10 (x+1)
Is defined in
x+1>0
x>-1
I don’t really know how to write domains like that we do like (0,♾️)
You can write x>-1 as (-1, infinity)
So all log equations have a base domain of (0,♾️)? When would we use the inverse version
If log base a (x) is given
You have to make sure base a is not equal to 1
And x is positive
how would a base be equal to 1?
Sorry I’m just very confused because now I don’t know what to do with the + and - logs and ln
Do you know properties of log?
You can solve them by using these properties
change base is just a bit more tedious compared to product and quotient rule
I just sent he/she all the property
i know
Hmm
I haven’t done the properties yet so I don’t know how to solve with them
I just don’t know if the og domain changes when it is a natural log and I don’t know how to know if to use the inverse graph domain or the normal graph domain
Because I know log tiny2 (x) domain is the inverse but I don’t know what the other equations domains are
the domain of logarithms is always $(0, \infty)$ no matter what base you happen to be using.
Yukari
You can try experimenting with sketching logarithms on desmos. That may help in understanding
Im jusr paranoid cus we drew both these graphs in class and im worried i missed an equation for the other one
And I still don’t know how to find the domain because we don’t just have one log we are adding them together
Is the domain for LN also (0,♾️)
you can add the logs and convert into a single term then set the expression inside log to >0
I’m sorry I don’t know what you mean 😭
you have two terms log (x) + log (x+1) = f(x)
use the product rule here
We haven’t done product rule before
hm.. that is an issue then. you must learn the properties
I guess I’ll just leave it blank and ask my teacher in class it’s not worth the energy
Cus I have other problems to do
you must intersect the domains
alr
For these one 14 I don’t know if I should multiply or divide and for 18 I’m not sure how to get the +2 out of the log
that might not work always
It would be good if you provide context. I can't understand what you are trying to do?
it is kinda hard to read 😅
It would be better to type out your question and show working out
Sorry the question is asking to solve the equation algebraically
What the equation
it was refer to this case
12,14,16,18 I mainly have questions on 16 and 18
Can you focus on one specific question
16 I guess it’s the more simpler question
I just don’t know if I should do loge(3)•0.045 or loge(3)/0.045
So what is exact wording 16. I can't find the question
Show working out from the very beginning
Sorry it’s a bad picture I don’t bring my textbook to school since I don’t have a locker
Much better
I would take ln not log.
It looks like you are using base e though so it does not matter
ln(e^(0.045x)) = 3
Edit: ln(e^(0.045x)) = ln(3)
By definition of ln we end up with:
0.0045x = ln(3)
From here it should be easy finish the proof the key understanding how logarithms are defined
I know I should put it in the calculator and like either divide or multiply but I do know which at least that’s how we did it in class
Forget about the original question. Suppose we have ax = b. How would we make x the subject?
Divide each side by a
We divide both sides by a. Because ax/a = x from equivalent fractions. Hence we get x = b/a
So what do we do in question 14?
Divide?
Correct
Ok and for 18 I don’t know how to get the +2 out from the log
honestly theres no need to remove it
lemme see the q again
1s
,rccw
how bout
And there’s no like tiny number so I can’t do that
i didnt understand....?
I don’t know how to convert the equation because I don’t have a b value
if a base is not visible, there should be a line in your syllabus telling you what the default base is. usually it's 10 in algebra/precalc and e in calculus.
Oh ya
its not given so its 10
always double-check with your syllabus though!
This doesn’t seem right
keep these 2 in mind
- if no value is given its 10
- if ln is given then the base is e
no its wrong
I don’t know what I did wrong
because
there is quite more than one issue here.
From the other side ?
Huh
and also btw if you have 10^-2 for instance you cant divide it by 2 and make it 5^-2
nope
It would be 12
nope
I’m so confused
8?
10^-2 is?
0.01
X=-1.99?
yep
Ty
you can only work on exponents with these rules
we used the negative exponent rule in that q
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I don't understand when a force has a positive or negative sign
wouldn't it depend on what direction you've defined as positive?
they are elastic forces
doesn't matter what kind of force or even vector they are.
yes, but since the spring force is a restoring force, doesn't it always have a minus sign?
$F_e=-kx$
Mr. Penguin
so if z is the direction positive
F1 =+ , F2=+ , and F3=-?
so kx+kx-kx
like this
I mean you can always define whatever coordinate frame you'd like
But this is ok
though with your choice of positive direction, wouldn't the signs be the other way around though?
perhaps I am misunderstanding something; if so I will apologize in advance.
The only important thing about the restoring force is that it is antiparallel (i.e., opposite) to the velocity vector. Whether it is mathematically positive or negative is not meaningful ultimately
It seems that I just need to consider the absolute value of -kx and then put the signs according to the diagram
thanks!
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I don't get how we get 2L -1w
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Are there no solutions for this? I always end with sec (started from left)
!show
Show your work, and if possible, explain where you are stuck.
start from right, 1 + sin^2 is cos^2, so RHS is just cos
divide by sin, you get cot + tan = cot
would be true if it was $(1+\sin^2(\theta))\cdot \sec{\theta}$
lyric
no nevermind im wrong completely
would be true if it was $(1-\sin^{2}(\theta)) \times \sec(\theta)$
Johannes Kepler
yeah minus mb
put it all in terms of cos and sin, becomes simple from there
*when you remember that the original equation must be defined
just did that, you get $\cos(\theta) = 1$
Johannes Kepler
heres the thing i did
$\sin(\theta) \cdot \left(\frac {\cos(\theta)} {\sin(\theta)} + \frac {\sin(\theta)} {\cos(\theta)} \right) = 1 + \frac {\sin^2(\theta)} {\cos(\theta)}$
Johannes Kepler
then multiply in
LHS becomes $\cos(\theta) + \frac {\sin^2(\theta)} {\cos(\theta)}$
Johannes Kepler
wait if u dont mind me asking howd u get 1? wouldnt it be cos/1 as sin cancels
after this
$\frac {\sin^2(\theta)} {\cos(\theta)}$ are on both sides, so cancel
Johannes Kepler
then you are left with $\cos(\theta) = 1$
Johannes Kepler
so is there no actual solutions
no, $\theta = 0, 2\pi, \dots$
Johannes Kepler
no you are correct
these are solutions, but cot is undefined at these angles
so no solutions
e.g. $\cot(0) = \frac {\cos(0)} {\sin(0)} = \frac {1}{0}$, undefined
Johannes Kepler
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Can anyone help me with mcqs
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you can send screenshots of a problem you're stuck on.
however dont send downloadable files like explained above
I have answer keys for these but I want someone to explain & let me understand these
<@&286206848099549185>
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And also, which ones in particular?
All
No
In every mcqs
Well you should try them first
And see where you get stuck
Otherwise we can't just know what you don't understand.
And with 100MCQs we're not exactly out of the woods...
Or at least the first few ones. The whole thing seems to cover a significant portion of a typical multivariable calculus course, so you should've already seen stuff pertaining to domains, ranges, partial derivatives, critical points, tangent planes, local extrema, constraint optimization, double integrals, change of variables, change of order of integration, Green's Theorem, triple integrals, Gauss' divergence theorem etc.
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i have a feeling that AC is 10, but does anyone know why?
OH

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<@&286206848099549185> sorry I am not patient and I'm getting sleepier by the minute
Bro….. do not murder me
Dexter…..
Bro
My final
Is on
Thursday
This is the last topic
The final is worth 60% of mg grade
In so tired
I've been studying all day
So what do you need help with?
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@shut hull, I hope how I explained it will help
.reopen
✅ Original question: #help-39 message
Nah bro
I don't mean this as an insult, but do you know what a Taylor Polynomial is? Cause if not, that's smth we should go over
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How do I get R? I know it's about solving for x with the other side being 1 but no combination I can think of gives a right fucking answer
zoomed in
Nevermind I got it. Used symbolab because I'm a fuck up that can't not rely on calculators for everything. I still don't understand this shit and never will.
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I need help with De Morgan's law on complement of intersection of two sets
I can't understand the logic
so you need help understanding $\neg(A \land B) = \neg A \lor \neg B$?
x : x belong to (A intersect B)'
x : x does not belong to (A intersect B)
how do we come with the conclusion that
==> x : x does not belong to A or B
Yukari
sorry for the LaTeX mixup.
if I restate that last line as "x does not belong to A, or x does not belong to B", would that make sense?
I can;t understand how it came to that conclusion
so let's think about it.
if an element x is in both A and B, then x is in their intersection.
agreed?
yes
no because x is strictly A
excellent, we're getting there.
ok
x is strictly in B
nicely spotted. and obviously if x is in neither A nor B, then x wouldn't be in the intersection.
that is symmetric difference of A and B
but we now see that to disqualify an element from being in the intersection, you only need to kick it out of one of the sets.
so if it is not in the intersection, then necessarily it is either not in A, or not in B. or both.
that's why if x is not in the intersection of A and B (equivalently, if x is in the complement of the intersection of A and B), then either x is not in A, or x is not in B, or both.
I hope it was clear.
why cant x be strictly A or B without the intersection
what do you mean?
why the shaded part not possible
not possible for what?
if x does not not belong to the intersection of A and B, the shaded part is possible too
does not, not?
ah sorry does not
did you intend the double negative or is it a typo?
right.
I never said it was not possible.
in fact, that's exactly what I mean when I said either x is not in A, or not in B, or both.
if you insist on expanding it fully, either x is not in A but in B, or not in B but in A, or not in both.
but De Morgan does not really care about what sets x is in with the way it is traditionally written, because if I say not in A or not in B, I'm leaving open the possibility of saying not in both.
and another reason for not being explicit (especially later on) is when you get to know the generalized De Morgan law (for any number of sets).
so he took it logically
you're not going to want to sit there and state (in A and B and C and ... BUT not in Z, or in A and B and C and ... BUT not in Y, etc.).
yes, you can also view this from a logical perspective.
which is this way of writing.
but ultimately, it's the same concept applied to different objects.
the idea is always that if an element is not in the intersection of some number of sets, then it must be OUT of at least one of those sets.
woah
alright I will go with the possible explanation that x is not in A or B, concluding x is totally outside of the circles
what do you mean, x is totally outside?
in fact, be careful with how you word this part:
x is not in A or B
notice that I worded it as x is not in A, or not in B.
x is not in A or x is not in B yeah
your wording implies $x \not \in (A \cup B)$. my wording implies $(x \in \overline{A}) \cup (x \in \overline{B})$.
Yukari
De Morgan concerns itself with the latter.
so lets start once again, I mean we came to the conclusion that x does not belong to A intersect B
therefore, x does not belong to A and B, am I correct
correct, provided you take that 'and' logically.
as in, x does not belong to A and B at the same time.
x does not belong to A and x does not belong to B?
now if you word it this way, that 'and' is an 'or'.
oh I see
remember what I said earlier.
or, if it helps visually...
if x is not in the red area, then necessarily it must be outside the red area. but there are three places it can be: the green area, the blue area, or the yellow area.
Yes this
if you agree, then we can say that if x is not in the intersection (red area), then it is either out of A (placing x in either the blue area or the yellow area), or it is out of B (placing it either in the green area or the yellow area).
and that is the gist of De Morgan.
what
hm?
what point does he try to make then
think of it this way.
suppose you have a compound sentence, and you claim that not everything in that sentence is true.
more concretely, let's say someone says "oh A and B and C and D..." and your claim is that not everything in that sentence is true.
ok
now, "not everything is true" sounds like a hard claim, especially hard to prove. but because of De Morgan, you can turn this claim into an easier one: "at least one of those things is false".
isn't that much easier to attack?
instead of seeming like you need to show everything is false, you now only need to show one of them is false, and the whole sentence crumbles by De Morgan.
okay yeah
okay i see
hitting one except all
it's like a domino effect.
if someone says "A and B and C..." and you tip one of the dominos, the whole thing crumbles.
though it is worth noting that De Morgan's laws come in two parts, and this is but one of them.
so how is it related to this
well suppose then you want to prove that an element is not in the intersection.
yes
by its nature this would be rather hard to prove, but if you invoke De Morgan, you can now target any one set involved in the intersection and prove that that element is not in just ONE of the sets.
instead of having to consider every single one of them.
please re elaborate this
you can now target any one set involved in the intersection and prove that that element is not in just ONE of the sets.
instead of having to consider every single one of them.
you want to show that an element is not in all of some number of sets at the same time. at first, you might think we have to somehow show that it is not in every set one by one.
De Morgan says that you can do the same thing by just showing that it is not in just one of them, because then it wouldn't be in all of them at the same time.
what does 'in just one of them' mean
suppose you want to prove that an element is not in A, B, C, and D at the same time (that is, their intersection).
then, it suffices to prove that the element is either not in A, not in B, not in C, or not in D. if the element is not in as much as a single one of them, then surely you agree it can't be in the intersection.
wait a neither nor condition?
or maybe more concisely, if you want to prove that an element is not in the intersection of A and B, then it suffices to prove that it is either not in A, or not in B (basically, it is not in one of the two sets).
this can be generalized to any number of sets, but you're more focused on two sets, so let's stay there for now.
exactly, because multiple sets make me think harder
it's technically the same idea, and maybe you'll see it later.
but if you want the two-set version, this is it.
and another condition maybe that the element is not in both
so ultimately whats the conclusion
that is handled by stating that it is either not in A, or not in B.
the conclusion is De Morgan. there's nothing more to it.
at least from my point of view. unless you want to generalize this, which is up to you.
is this phrase "either not in A or not in B" converted to set operations directly resulting in the conclusion?
yes.
either not in A or not in B, in set language, is x is in the complement of A, or x is in the complement of B.
which is how De Morgan for sets is usually stated.
actually my problem was
I was assuming more variables and possibilities whereares He did not
perhaps, yeah.
alright thank you so much!!
no worries.
'twas a good exercise.
tremendingly stressful
because I was just promoted to 11
with a class 10 brain, very difficult
we've all been there. you got this.
thank you..
I just realised a great mistake
A' means U - A = B right?
and vice versa?
for B'
@honest vigil
A' means U - A, correct, but U - A is not necessarily B.
U - B is any element of U not in B. this does NOT necessarily mean A.
some elements are part of neither set.
thats why I said U elements
framing more better
U - A = elements of U which do not contain A but contain B
also, "not containing A" is not exactly right. "not contained in A" is better.
I mean elements in U along with B without A
U - A = elements of U that are not contained in A.
this statement does not imply membership of B.
wish my english was better
U - A should only talk about U and A.
and same idea for U - B
correct.
if I had taken these into account, I wuld have understood what De Morgan meant by saying "either not in A or not in B"
now I finally understood
Finally, thank you so much
no worries, glad to help.
alright I will close since I ned to bath ah
thank you for saving my hours
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Prove that (A - B) U B = A
Given:- B (subset) A
My steps:-
x belongs to B => x belongs to A
(A - B) U B = {x : (x belongs to A and x does not belong to B) or x belongs to B}
Is this approach okay ?
Seems pretty solid to me
You should continue though
next step:
(A - B) U B = {x : (x belongs to A and x does not belong to A) or x belongs to B}
is everything okay here by logic?
Did you typo
You should backtrack a bit
Your conclusion is wrong to begin with
ok lemme see
What im saying is that this statement is a contradiction
It is never correct
I know therefore it becomes an empty set
but A - B is not gauranteed to be empty
so lemme re check
But it should be x does not belong to B you wrote A
I thought if x does not belong to B, should not with A as wel
but it isn't necessary
which
yeah
I think it should be
(A - B) U B = {x : (x belongs to A and x does not belong to B) or x belongs to A}
Yes
So if union of a subset (A - B) with A
it results in A
because (A - B) is a subset of A
oh wait I got the answer
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Hi! I have a question.
Mhmmm.
I don’t know if I describe it clearly
This problem (Figure 1) reminds me of the Poncelet Porism (Discovered by a teacher himself). I’m not sure how to describe it clearly in words, so I drew a diagram instead. In Figure 2, α is a fixed angle, P is a fixed point, and Q is the moving point whose trajectory is a circle. Since the ratio PQ:PM is constant, we can obtain:
- The trajectory of the passive point is also a circle.
- Let O₁ be the center of the circle on which Q moves, and O₂ the center of the circle on which N moves. If the radius of circle O₁ is r₁ and that of circle O₂ is r₂, then we have r₁ : r₂ = PQ : PN.
- PO₁ : PO₂ = PQ : PN.
I already know how to prove the three statements above. Now I want to use the Poncelet Porism to solve the original problem (Figure 1).
In this problem, based on my drawing, I unexpectedly found that the locus of point F is an arc whose center is the midpoint of BC and whose radius is half of side A. The arc starts on side AB and ends on side AC. This seems to match property (1) of the Poncelet Porism.
The key question is: in Figure 2 there is one active point and one passive point, but in this problem there are two active points M and N and one passive point F. Does this situation still satisfy the Poncelet Porism? If it does, how can we use the porism to prove it?
First, r_O equals one half of r_B, which equals one half of AB, which equals a/2. (I feel that this follows from property (2), but at this moment I still cannot justify why r_O : r_B = 1/2.) Then, from property (3), we can obtain BO = 1/2 BC. (But again, just like the previous step, I still cannot justify why this is valid.)
If these two steps can be established, then we can prove that the locus of F is exactly that arc.
Is anyone watching? I really need help, thank you 🙏
Your problem is highly detailed so help might not be available for a while. Either wait or see a relevant channel to post your question in in the 'Advanced Mathematics' or the 'Early University' categories
Ok, thanks!
<@&268886789983436800>
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how does his last limit prove 6.27. The way he convers 6.27 it should be $\lim_{L(k+1)\to0} \frac{k}{L(k+1)}$ I don't see how proving the limit as k goes to 0 is related or how it helps
BigBen
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You're a teacher and a company offered you two profit models. Both profit models can get up from 4$ to 6$.
-First Profit Model: includes $4 per completed lesson and $2 per client no-show. If your performance rate (student retention) stays at 70% or more at minimum 7 clients for 3 months and tutor attendance rate is 85% minimum, your profit is increased to $5 per completed lesson and $3 per client no-show. If your performance rate (student retention) stays at 80% or more at minimum 7 clients for 3 months and tutor attendance rate is 85% minimum, your profit is increased to $6 per completed lesson and $3 per client no-show
- Second Profit Model:
Lesson Milestone Base Rate Retention Bonus Total per Lesson
1 – 10 $4.00 $0.00 $4.00
11 – 25 $4.00 +$0.50 $4.50
26 – 40 $4.00 +$1.00 \ $5.00
41 – 55 $4.00 +$1.50 $5.50
56+ $4.00 +$2.00 $6.00
For client no-shows, it stays only at $2.
Which model is mathematically more profitable? First or Second?
Draugr
Compile Error! Click the
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(You may edit your message to recompile.)
You are a teacher and a company offers you two profit models. Both models allow earnings to increase from $4 up to $6 per lesson.
\subsection*{First Profit Model}
The first model is performance-based and defined as follows:
\begin{itemize}
\item Base rate: $4 per completed lesson and $2 per client no-show.
\item If the performance rate (student retention) is at least $70\%$ with a minimum of 7 clients for 3 months, and the tutor attendance rate is at least $85\%$, then:
\[
\text{Rate} = \$5 \text{ per lesson}, \quad \$3 \text{ per no-show}
\]
\item If the performance rate is at least $80\%$ under the same conditions, then:
\[
\text{Rate} = \$6 \text{ per lesson}, \quad \$3 \text{ per no-show}
\]
\end{itemize}
\subsection*{Second Profit Model}
The second model is milestone-based:
\begin{center}
\begin{tabular}{|c|c|c|c|}
\hline
\textbf{Lesson Milestone} & \textbf{Base Rate} & \textbf{Retention Bonus} & \textbf{Total per Lesson} \
\hline
1--10 & $4.00 & $0.00 & $4.00 \
11--25 & $4.00 & +$0.50 & $4.50 \
26--40 & $4.00 & +$1.00 & $5.00 \
41--55 & $4.00 & +$1.50 & $5.50 \
56+ & $4.00 & +$2.00 & $6.00 \
\hline
\end{tabular}
\end{center}
For client no-shows, the compensation remains fixed at $2.
Which profit model is more profitable?
Draugr
Important question, how much does a lesson last / take to do in time
45 minutes per lesson.
15 minutes for the prepration.
Total 1 hour.
Any particular chance for no-shows?
No, but it will depend on the student if they decide to do no-shows.
Id assume that we will consider a hard limit of 6 / 8 hours per day taken.
Yes.
Well, from a theoretical standpoint, 56 can be reached in about 10 days. Even if client amount increasing over time, id say you reach the peak of the second profit model in far less time
For every 25 lessons, there are 3-4 no shows.
Since for the First Model you have a 6 month cap that cannot be avoided.
Over an extended period of time, the first model is technically better in an optimal enviroment.
I forgot to add, each client only goes for 2-3 lessons per week.
But considering the possibility of failing the 3 month condition for amount of clients, or simply a relative decrease of client noshows in the 2nd model
That applies on both profit models.
any cap on total clients?
If you get a good headstart you can prob reach peak amounts in the 2nd model in like 2 months.
And even if you dont, theres still a gradual increase to compensate for the time it takes.
But if the teacher has a goal of an long term bigger profit, would it be the same answer?
Since second one only has a stable 2$ no-show.
if for every 25 lessons you have 4 no shows theres a 4$ difference total
Havent particularly crunched the numbers, but i think that it would probably take a few years for 1st model to get back on the speed of 2nd model headstart.
Thanks for the answer. I really appreaciate it. 
I'm already in the job, they offered me to switch. I'm working with them for 3 months now (1 month probation).
Id guess ask coworkers about it, check how many have the 2nd option, etc...
And evaluate what has been your progress on this 3 months
So far, I will get stage 2 in a month now and some of my students are newly assigned to me (a month ago). And on my 1st month evaluation (I already passed the requirements so I'm just waiting for the 2nd month's email and currently performing on my 3rd).
On the other hand, the 2nd profit model got offered to everyone. Meaning, it is new for everyone.
if you got any friends inside the job and theres no NDA (or you dont really care about it, lmao), just talk about it, see what other think about it
like, the difference in payment is basically none
!occupied
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@flint basalt
yes? whyd you ping me
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hi ineed help in integral if its possible
Any specific one?
those two
so
let me start with a if it was 1 then its arctan if 0 impossible
but if i need to complete than i need to talk a variable changement
and i couldnt know what it is
or if there is other cases
multiply by 0 sonny
0??
Try to divide the numerator and denominator by sqrt(a).
think trig substitution
They already have the integral for arcsin, so dividing numerator and denominator by sqrt(a) and substituting is the easiest way to get back to that form.
but sub x with what ?
Do that first.
ok i did it
If you distribute everything in the denominator you should get something that almost looks like the derivative of arcsin.
ohhhhhh get it but like no metter a or i need to do her intervall
What?
a if it was 0 the form is false and if it was 1 then its artan
You said that a can't be 0, it also can't be negative, so you can do this regardless.
so i think in this case we need to do R positive not 0?
I'm not sure what you're asking. For the denominator to even be defined you need to have a > 0.
ok this is what i need thank you sooooo much
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If G is an abelian 2-group with distinct invariants, how can we construct an automorphism with the largest order? The order will be a power of 2 since the hypothesis implies Aut(G) is also a 2-group
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LINEAR ALGEBRA HELP NEEDED
23a and b make sense, I got A^2=I and confirmed M^2=I. 24 is where I am confused.
I will send my work one sec
24 still beign worked through but im confused
In the future, please make the first message you send the actual question since that's what the bot pins. This saves us the effort of having to change the pin manually.
That being said, the dimensions here are inconsistent - remember that matrix multiplication is commutative. Idk if that is what's tripping you up.
But notice that the idea in 23a is ||a matrix with 1 and -1 on the diagonal can square to the identity||. If you need another pointer, consider ||blocks||.
thanks for letting me know

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A = -D doesn't make sense, they ain't the same size
fuck....
CSP's first spoiler is a good idea here though
and it's essentially what you're trying to do with that "A=-D" thing
lord help me
idk what im doing
this is all I have
and even then im not confident
these would be the correct sizes inside M yes
the other interesting thing about 23(a) is that it doesn't matter what you put in the 3 spot, you'll still have A^2 = I
hmm
so the other hint I got is that you shouldn't give a crap about the C, pick only A and D so that M^2 = I whatever C is
am I on the right track
now theres a reason why AC+CD=0
hence why i said A=-D
or like
now it's partitioned and not just assumed
also you haven't corrected the error CSP told you in the first place, should be CA + DC but w/e
why does that order matter
ohhhh
fuck
DONT ANSWER THAT
listen... im new to this...
so basically ur saying
because positions 1 2 and 4 are I, 0, and I, whatver is in position 3 is irrelevant
ohhh
wait
bruh
C cant be 0
nah, the idea is that with a very particular choice of A and D you can make C irrelevant in the computation of M^2
i dont get it
think simple stuff
diagonal A and D
this all i got
there ain't a ton of diagonal matrices with A^2 = I or D^2 = I
am i supposed to be recalling something
nothing special no
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shut your egg ahh up
@midnight haven Has your question been resolved?
rude where?
i was talking to the robot
it came across as if it was aimed at whoever triggered the bot
Don't assume, I don't like robots it's that simple.
I think the bot might automatically trigger it maybe if it detects someone pinging twice in a row? because I've noticed the bot doesn't delete the message command if someone triggers it
That being said I do agree with the sentiment of what you said that what was said was mildly disrespectful towards that rule
It was triggered here, it doesn't auto trigger, often a few of the regulars will send delete commands for the bot because they don't want to deal with arguing with the person over the server rules
Ahhhh
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how do I know if a point is on a line parallel to an axis in 3d?
if you have the equation of the line, sub the coordinates of the points into the line and see if the equation is satisfied.
uh something like this:
P(2, 3, -1) is apparently parallel but idk how and idk what other points are parallel to the z axis
I think the question is asking that what point can you join to P with a line such that the new line is parallel to the z-axis?

