#help-41
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Meaning [39,57] is the interval of all days within 3 standard deviations of the mean
so its 3?
,calc (57+39)/2
Result:
48
Yeah
Yeah same thing
what does it mean 6 std
3 standard deviations to the left of the mean + 3 to the right = 6 in all
oh okay
and how can i do part C?
What’s the z-score formula? Substitute in what you’ll have so far and it becomes obvious.
Yeah
i see
thanks
@weak zinc CHARRRRRRRT
i need help!!
why do we have to convert r to 0.21
or 0.021 i mean
i think
That’s 2.1% as a decimal 
hehe
What about this oneee
So I know it can’t be A
B doesn’t sound right
So either C or D
WAITTTT
i got it
That was easy lol

awwww
Better (assuming you count sign when determining “bigger”)
Hm so how would I decide what’s his worst one is it stats
That’s the best one 
How do did you get that it’s the worst
Idk I just looked at the mean and standard deviation and cuz it was lower than the rest I just assumed it was his worst
Just find the number of standard deviations above/below the mean
That’s what I was referring to here
I mean we don’t know what 1 standard deviation is here tho cuz it doesn’t tell us right
73 + 5 is 78 which is his second highest isn’t it
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why is the first = true
it should just be $=|\emptyset|$
Ayanokoji (ALWAYS PING ME)
What does the arrow mean?
@bronze shuttle what does the arrow mean
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is this right?
is this a test?
can a constant graph be linear
yeah it has a slope of 0
is thos right? the second and first differences are bith not the same byt those are the only iptions
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can someone help me with this
this is what i did:
oops
wait
checking my work using a online calculator it gave me this
any idea where im messing up?
you used lhopital wrong (your derivative was wrong)
derivative of ln(1-x) is what again?
it’s derivative of the numerator divided by derivative of the denominator
1/(1-x)?
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im having some trouble integrating this to find the arc length
is there an integration technique i can use to make this easier
i tried using a math solver online and it said to use an identity involving sinh but that isnt covered in our course
$4+(e^x-e^{-x})^2=4+e^{2x}+e^{-2x}-2e^xe^{-x}=+e^{2x}+e^{-2x}+2=(e^x+e^{-x})^2$
everg
huh
I don t understand the question ... my I made some mistake ...are there some steps that are not clear ?
ooh ok
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on step 3 how ddid that happen?
I've already looked at the proofs for the sum and difference of a cosine and sine
Now I'm looking at the tangent proof
on step 3, I'm a little confused at how it happened really
you mean the third equal sign?
You just spilt it into two parts literally
You just divide denominator and numerator with the same value
It’s like 4/6=(4/2)/(6/2)=2/3
yes
Oh I think I get it now
Thank you
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heya
o
it is formula
wdym
nope
im so confused
(a-b)² = a² +b² -2ab
wait is this quadratics
try using this against (m-2)²
yes
ohhhh okay, welp i dont gotta worry abt that and all then since i thought this wasnt one xd
yep thanks
no problem
cya
se eya
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what does it mean by maximum and minimum values
whats the max output u can get from that expression is the max value
and the same for min, the least value u can get from that expression
oh kk
how do I do it
think how u can make it one term here
any formula like maybe sinAcosB + cosAsinB = sin(A+B)
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idk
construct a right angle triangle with base = 3 and perpendicular = 4, then write the hypotenuse
then try to make this expression
into sinAcosB + cosAsinB
so that it equals to sin(A+B), then u can easily get the max value
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can someone tell me if this is correct in finding the general solution of a tan equation
if $\tan(3x+\frac{\pi}{2})=1$, then $3x+\frac{\pi}{2} = \arctan(1)+k\pi$ and you continue from there. the $k\pi$ comes form the periodicity of tan. the other $k\pi$ you added later was not justified.
Mohamed Mohsen
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Puzzle involves thinking outside the box and some mathematics.
The goal is to connect all nine circles using exactly 3 straight lines by the shortest route, without lifting the pen. Each straight line must pass through the center of one circle. Start of the path should be on the edge of the circle and path should end on the edge of the circle. Each circle you should pass (use) only once.
Calculate the total path with the pencil, taking that the distance between the centers of two adjacent circle is equal to 6, and the radius of each circle is equal to 2. Divide the number of circles with the total path. Do not round up.
A=3rd decimal digit
B=17th decimal digit
C=12th decimal digit
X=4th decimal digit
Y=16th decimal digit
Z=13th decimal digit
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✅
Nobody is going to be able to make sense of your question, post the original
- You haven't given any details about how these 9 circles are positioned
- You haven't even given a single word of explanation as to what the list at the end is about
List at the end are the specific digits in the answer
So for example A is the 3rd decimal digit so in 3.193, A = 3
I just found this and wanted to know the answer and how to solve it and thought someone here might know
Can you post the original question? It seems like there's a lot missing here
https://www.geocaching.com/geocache/GC5HCFH heres the page
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I think the question is just nonsense, it's clearly impossible for any 3 segment line with endpoints on the circles to pass through all 9 circles, even disregarding all the rest of it
Oh wait, it just says the endpoints of the path, there are solutions in that case
@heady valley Has your question been resolved?
There is definetly an answer, just on the page you can see over 30 people solved it
Finding a solution is easy, proving minimal path length is not
I suspect it's this, but good luck proving that:
@heady valley Has your question been resolved?
Well thats what I need help with
I think its something about triangles and stuff idk
@heady valley Has your question been resolved?
Ok Ill see if the answer is correct and get back to you
Can you write that number in decimal with the first 17 decimals digits? @graceful coral
In the words of my math teacher
Just press calculator
My calculator cant show that many digits 💀
I have no idea
,w 18+20*sqrt(2)
@heady valley aight here ya go
ty
Is this a puzzle for a cache or something
yup
Sadly the answer is wrong so rip
If you want I can give you the page to the cache and you can try solve it
And when you do slide me the answer 😏
There are millions of geocaches worldwide and probably even some near you right now. Visit Geocaching.com to see just how many geocaches are nearby and to get the free Official Geocaching app.
3.5 difficulty is so biased
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ok, so I think I came up with a solution to thsi
ok
can you tell me what are the properties of the tangent line
the tangent line is perpendicular to the radius
that is what I meant
idk how to express it differenmtly
ok I see that
now u can use that to construct a right triangle
ok I saw that idea
just above the C make a new point called Z so Now you have triangle MCZ
but even then since the MZ lenght is the hypotenuse how do you still figure out X and Y
i am going to spill the beans and say that the way i did it was using coordinates since this is due in 40 minutes
oh nvm im dumb
np
so is MZ root 8400
we dont need that
let M be the origin (0, 0)
ok
now from the triangle you can calculate the slope of the line MZ
okay I lied you will need the length of MZ
ok
so you do CZ over MZ
the length of CZ over the length of MZ
(20)/40root6
gives you the slope of the line MZ'
now you plug into y=mx+b
I would suggest opening desmos so u can visualize what we are doing
whats our b value again
0
becaause we want the line through the origin
yep
now to construct the circles on the graph
ok
it's these equations for the circles
now we have succesfully graphed the problem we are trying to solve
ok
the numbers that are in brackets with the x are the x coordinate of the center just negative, and with y we dont have any because we want the center on the x axis
like i am getting about 42 to 73
now the second circle is the one whos intercepts we are trying to find
so 31
well you can look at that or I think if your teacher is going to be grading your work we can do a calculation
ok what would be the calculation
so for the second equation of the circle we can substitute for y, we will use the equation of the line so y=20/40sqrt(6) x
just y
like this
this gives us a quadratic after simplyfication
and the roots of the quadratic are the x coordinates of the intercepts
well u have to expand out the first bracket than square the second one and add like terms
it might be easier if you would first cancel out the 20/40 into 1/2
its a smaller number
that would just reduce it down to 1 /24 x^2
yea
so whats after that
you calculate the roots of the quadratic you get
is the only root 0?
no
well one root is 41.92 and second is 73.28\
ooh you meant the whole thing
that is the difference yea
but that is not the answer
31.36 is the length of the base of the right triangle that you can construct between the two intercepts
right because the actualy answer is between 40 and 79. something
u need the length of the red line between the intercepts, but u have the length of the blue line between the intercept X and the green line
ok
ok
it is the same angle as between the red and blue line
ok
31.6 ....
yea
It should be an integer answer at the end
so 32 rounded up
I calculated when the line of the slope intercepted the second circle and used the distance between points thing
Anyways they probably won't care it's the last week
well anyways I hope I was of some help, but my brain is not braining anymore its almost midnight so goodbye
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Maybe I'm just tired but the n in the text is one more than the n in the lemma, right?
Because (c_0, ..., c_nX^n) are the coefficients of n+1 monomials
@fathom cape Has your question been resolved?
@fathom cape Has your question been resolved?
@fathom cape Has your question been resolved?
yes, you can google the lemma's name and everywhere else it shows up as either deg(g(x))=n-1, or n+1 inside the square root
see for example: https://www.math.auckland.ac.nz/~sgal018/crypto-book/ch19.pdf
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forgor conditional probability could anyone help
@burnt cairn Has your question been resolved?
First of all, do you think the A and B are dependent or independent in this scenario?
Independent is when = P (A|B) = P (A)
If one is causing or interfering with the other it'll be dependent.
Use Baye's Theorem to calculate the probability.
P ( E ) = P ( E | F ) P ( F ) + P ( E | F c ) P ( F c )
@burnt cairn Has your question been resolved?
nvm i got it ty
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for a tank mixing question like this do i still have dy/dt as rate in - rate out
Your welcome!
I believe so because the net rate of change in salt is the rate it goes in subtracted by the rate it leaves the tank
thanks!
i’ll leave this channel open while i solve
Ive done sone problems that are similar to that but only have a rate in
that sounds like basically the same thing just a little easier
i think the hardest part is finding the equation for the rate out since volume is not constant
Send solution if you get it 🙏
@stone mantle Has your question been resolved?
ngl i laid in bed for half an hour ill start now
@stone mantle Has your question been resolved?
heres what i got
<@&286206848099549185> can someone please check my work?
please my assignment is due in 28 minutes 
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Let u = denominator
The derivative of (x)^1/2
Just Du= (x)^1/2?
Just substitute now? Did u forget u sub
No i just showing the u and du
K
It's hard 😭
So , i will say the things i know
So the U is 1+x√x and then the du is √x dx ?
I mean, if u know then why is it a "?"
I'm just making things clear to me sir
Yes the u has the du and same on the numerator
Yes but du is not in the numerator
are you doing u sub?
now u is the same thing
Ur integral should be
$$\int \frac{du}{u}$$
JustToPro
Not what u wrote before
which is same as integrating 1/u in terms of u
Yes it seems like that
yea it is 1/u because u is on the bottom of the fraction
justtopro should be able to help well im off
Hmm
can u help me ? (help 45) really need
Yes
i might be wrong but double check your du
(x)^1/2?
hm, it was x * √x, try rewriting it as 1 term of x
you're missing something a little there cuz you got the idea
x(x)^1/2
you remember exponent rules?
Yup
right, so if you have x * x^1/2 what does that become?
there you go
that became your new du
because you wrote du as x^1/2 as your du in the beginning
i mean your new u value, sorry
Its 1/u because u is denominator
mhm
I think i'm wrong
Okay sure sir!
im a girl lol
ok sure sir!
ohh, okay so remmeber when you simplified the x * x^1/2 as x^3/2?
Yeah
Yea
you're missing something with that
Dx
...
It's okay
Now u • du?
Wait in this problem do we need the power rule of integral?
du = 3/2 (x)^1/2dx but you want to replace the numerator part right?
not really, it is u-sub but because your derivative has a integer multiplied to it
Yes we wanna get rid of that.
yeahh but you can't replace, or as you say get rid of it unless you set du as the same as the numerator
the du = 3/2 (x)^1/2 dx is almost the same but we don't want the 3/2 there
what should we do?
Move? Infront of integral?
allllmost got the idea
Not right?
no it is right
buuuut
say if you wanted to solve for 2/3x = 1 how would you solve for x?
Omg another math question.
yeah, thats how i teach people lol
Wait hahahha
it keeps their brains moving
i promise you can do it i think you're just overcomplicating it is all
Is it multiply?
Yes
soo if we apply the same idea to du = 3/2 (x)^1/2 dx , we get 2/3 * du = (x)^1/2 *dx
dooo ya agree?
2/3?
mhm, because 3/2 * 2/3 = 1
Leme write
So i need to multiply 3/2 on Du?
2/3 to du
because you multiplied 2/3 to the 3/2 (x)^1/2 dx part
for it to become (x)^1/2 * dx to be replaced or get rid of
the whole point of U-sub is to make U or du match the part of the equation for it to be replaced
here let me write it on a piece of paper its better than explaining it
it's a pleasure.
,rotate acw
i'm using laptop rip
thank you lol
the boxed part matches the numerator, thats why we want to get rid fo the 3/2 for it ot fully match
and for that we multiply the entire thing by 2/3
i get it now, so the 2/3 help us to make our du and match the numerator.
yess!!
im gonna start using the paper hold on
alright so now you can put the 2/3 in front of the integral
i split the original top equation into 2 parts for easier replacement
now all the stuff becomes u's
lmk once you absorb all of that
okay let me process first
yup yup
do the sqrt x dx will be cancelled cauz of the numerator?
sooo this is where u * du gets applied
it doesnt get cancelled it actually gets replaced
with u's and du's
yea because they are equal?
and now, 2/3 will move infront?
yup yupppp
thank you.
and thats how you get du / u
or in this case 1/u * du
because the u part replaces the denominator
okay now i'll try to solve
yupp js integrate like normal
dont forget the + C!
and turn the u's and du's back to whatever you made them equal from when they were x's
I'm done wait
i aint going anywhere lol
Im crying lol
why?
Ur the first person to say that to me
oh
Btw nice i like this anime
im planning to watch it sometime
yuuup
I'm Collage so this might help.
if it makes you feel better, the toughest part that everybody makes a huge mistake on is the algebra in calculus
i Agreed 👍
ohh btw can i add you?. i need to ask ur permission, its okay if it's not possible or your friends list are full i totally understand it.
yeah, sure i dont see why not
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hi uhm
so when i do
like
evaluating
nc0 + nc2 + nc4 + nc6 +...
im getting
2^n-1
why is it that
when i do nc1 + nc3 + nc5 + nc7 + ...
its also 2^n-1
is that correct ?
You mean $2^{n-1}$ or $2^n - 1$
YakuBros
$2^n = (1+1)^n = \displaystyle\sum_{k = 0}^{n}\dbinom{n}{k} = \sum_{\substack{k = 0 \ k \ \text{is even}}}^{n}\dbinom{n}{k} + \sum_{\substack{k = 0 \ k \ \text{is odd}}}^{n}\dbinom{n}{k}$
YakuBros
You can split into two cases according to whether a fixed element is in the combination or not, and thus reduce even/odd counting formulas for even n
Unfortunately, i dont have time to explain more, i really think that you will achieve to find out anyway
right, you could also do $0 = (1-1)^n = \sum_{k=0}^n \dbinom{n}{k} (-1)^k$ and derive that they are indeed equal from there, by extracting all the positive and all the negative summands
rbit
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Hi
Ismy proof that the centoid divides the median in the ratio 2:1 correct?
[GBD] = [GDC] = X (median divides into two equal areas)
Similarly, other triangles have equal areas.
Let the other two pairs have areas X and Z
In triangle ABC, [ABD] = [ADC]
X+2Y = X+2Z
Y = Z
Similarly, Y = Z = X
[ABG] = 2*[GBD]
Ratio of areas = ratio of bases (heights to be the same)
2:1
Proved.
@stoic locust Has your question been resolved?
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having trouble with both, not sure where I should start
1.1 $$ A \cdot B = AB cos (\theta) $$
1.4 $$ A \wedge B = AB sin (\theta) \hat{n} $$
dindu
<@&286206848099549185>
be careful with your notation
I assume A and B are vectors -- or are they scalars? it's ambiguous by what you've written
it's in the description of the problem
Problem 1.2 right?
they're vectors
yeah
i don't want the solution yet
just a nudge towards solving it
but seriously I think you mean $u\cdot v=||u||\times||v||\cos(\theta)$ and $u\land v=||u||\times||v||\sin(\theta)\hat{n}$
Take examples
Take the unit vectors ican j cap and k cap
Flip
i have bad eyesight so thats why i don't use the norm markings haha
not to make an eyesight joke but I see you lol
i mark vectors with lowercase letters and their magnitude with uppercase letters
hmmm but those are not coplanar
I dislike the vertical bars because astigmatism. it makes it hard to count sometimes
i need to show it for the coplanar case first probably because there's some pedagogical benefit in it
Ok take vector a and vector b and apply your condition
Hint - || is (a×a)×b same as (b×a) ×a ||
well yeah that's what they're asking me to prove haha
these are actually the same because cross products are associative but i'm trying to prove that it is
cuz a x a = 0
So (a×b) ×a = 0
no?
ul be disheartened to learn that it is not the truth
Yea so it forms a counter example
how? they're not asking me about commutativity
but associativity
as stated a x (b x c) = (a x b) x c
which should be true
oh wait
ig order should matter
(a×a) ×b = 0
(a×b) × a !=0
why so
yeah no i see it now
I tried to give you a hint but it slipped from your eyes ig
because (a x a) x b != a x (a x b)
due to the fact that a x b is perpendicular to a and not is not the zero vector
@knotty reef any ideas for problem 1
that would be the harder one
need to show that $$ a \cdot (b+c) = (a \cdot b) + (a \cdot c) $$
dindu
Let me think 
Take three vectors a b c
Take angle between b and c to be theta and angle between a and b to be phi so the angle between a and c will be theta + phi
(I think a graphical proof would be still much better in such cases)
yeah thats what i figured
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A man is dealt a poker hand (5 cards) from an ordinary playing deck. In how many ways can be dealt a straight ?
I searched this question on Google and I got confused if there is 9 or 10 sets of straight I can make
like here. why did they not consider A2345?
Because A can be 1 or 14
But not both at the same time
Well, he said he is playing poker with 5 cards so
10 sets
i would say 10
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Hi
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$x - 6^x = -3$
Alex
i had to get 5 decimals precision
i used this
$f(x_{n+1}) = x_n - \frac{f(x_n)}{f'(x_n)}$
Alex
$f(x) = -6^x + x + 3$
Newton Ramphson method right?
Alex
Alex
here i chose 1 because by inspection it is the closest number i can think of
$f(x_0) = -6^1 + 1 + 3 = -6 + 1 + 3$
Alex
$f(x_0) = -2$
Alex
$f'(x_0) = -6^1 \cdot \ln{6} + 1 = -6 \cdot \ln{6} + 1$
$f'(x_0) = -9.75056$
Alex
$f(x_1) = 1 - \frac{-2}{-9.75056}$
$f(x_1) = 0.79488$
this is correct like this, right?
Shoudnt it be xn+1 rather than f(xn+1)
where exactly
Yea the rest seems to be good
But this doesn't guarantee that this is the closest approximate of the root of the eq
Here
Alex
It should be x1 rather than f(x1)
?
huh but like everywhere it's this
$f(x_2) = 0.73905$
$f(x_3) = 0.73554$
$f(x_4) = 0.73553$
$f(x_5) = 0.73553$
Alex
so at 5th iteration it is repeating with 5 decimals
so i assume this is the end
am i right?
Yea
so, it is f(x_5) or x_5?
Yes 
Try both of them

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wlc
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If i have two lists A and B and they have the same number of elements and same mean, but different variances\
then i introduce list C where it's a merge of list A and list B
what's an expression for the variance of C?
,, \operatorname{Var} (C) =\frac{\sum_{x \in A} (x_a - \mu)^2 + \sum_{x \in B} (x_b - \mu)^2}{2n}
!Kiz__
is that even right? 💀
that seems sketchy asf
i think it's right, but why can you even do that in the numerator?
@split sail Has your question been resolved?
@split sail Has your question been resolved?
Never knew stats was this scary 
well... I think that is it
your denominator might need to add -1
but that depends on what you are working with
but if you want Var(C) in terms of Var(A) and Var(B), you might want to simplify that further
I want to express Var(C) in relation to elements from A and B
my grand goal is to show that Var(C) < Var(A) + Var(B)
If that is your goal, then from what you have, maybe try expand that square term out
And notice that your sum of squares can be expressed in terms of variance
because you need it to make it unbiased if it is sample
well hmm
i’m guessing we consider it as the population here
cuz “two lists”
right okay but my expression i have there
is probably right
tbh
bc i’ve done this question before and hmm i think i got it right
it is
like i can justify it now that i’ve written it down but how do i make it from the group up
without expanding the squares?
because $\sigma^2 = \frac{1}{n}\sum_{i} (x_i - \bar{x})^2$
Nonstationary Nickname
yeah, and you should have linear combination of variance
yes sure that’s the variance
since coefficient is > 1, then your proof is concluded?
no i mean how do i make an expression for Var(C) from the ground up and make it somewhat similar to what i had initially
or rather what do i do from the get go if i had to compare Var(A) + Var(B) and Var(C)
$Var(C) = \frac{1}{2n}\sum_{c \in C}(x_c - \mu_C)^2$.
!Kiz__
That’s where one would start naturally right?
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partial fractions
how would you get partial fractions?
i mean i simplified the denominator to 2x+t+tx^2
but i dont see a way
quadratic formula to factorise
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For
q2) I dont understand how they came up with the DFA (image 2)
q4) Could I just say that since its infinite its not regular because |w| = 2^x(3) where x could be any natural number and isnt bounded
q5) Could I just say that since w[i-10: i] implies that |w| = 10. Its finite so it has to be regular
q2) it's your typical "count something mod 3" automaton, but yeah they forgot to add some transitions
q4) so you're saying infinite languages can't be regular ?
q5) "w[i-10: i] implies that |w| = 10" what does that even mean ?
@proper umbra
w[i-10:i] is looking at the last 10 characters of the string w
shit I forgot in some cases they can be regular
w itself can be of any length, there just needs to be some substring of length 10 with more 1s than 0s
Say we had "count something mod 4" then it would have been similiar to this but without the q1 to q3 and q3 to q1 direct transitions and instead of 3 states it would be 4 states? with q_3 to q_4 being a, b and q_4 to q_3 being c and q_1 to q_4 being c and q_4 to q_1 being a, b?
How should I approach this one then
I think try to come up with an NFA
had a similar idea with an NFA in mind
alr lemme see if I can come up with an NFA
for the last 10 characters I came up with this to check if there are more 1s thn 0s. j represents amount of 1s and k represente amount of 0s
,rotate
p sure im not doing this correctly but idk how else to do this
self loop on 0, 1 for both btw
forogtot edit that
yeah.. doesnt feel very NFA like, maybe try building a DFA for language X first, it needs like 20 states I think (or you just say it has to exist because X is finite)
then you can just hook it up to an NFA
Damn I was trynna dodge that because it seemed pretty annoying
is there no other way without NFA/DFA
for something like this
I mean you know it has to exist
right
Im just wondering if something like this came up on my exam what would be the best way to answer it
for q5 specifically I would just take this shortcut and explain how I would expand it to an NFA that accepts A5. I dont think they would ever ask you to construct this, not with a number like 10
I see and what abt q4
Pumping lemma to prove its not regular?
If so how would I set it up
Im not rlly sure
yeah feels very unregular, you got the lemma at hand real quick?
one sec
They used Myhill-Nerode Theorem to prove its not regular but that was covered back then. In the current course they didnt rlly cover that theorem
This is how they did it
But surely its possible with pumping lemma too right
ok so I think ignoring the multiple of 3 part first will make it easier to get an idea
what if we take any p, then we choose w = 0^p 1^p, can you see where this leads us?
Ive proved thats not regular before p sure
I LOVE THE PUMPING LEMMA (also, what are you still stuck on, i came here with a dramatic entrance and the intention of helping but actually I can't really stay for that long sorry)
how would I use pumping lemma to prove this isnt regular
damn saw your message a lil late

we did this in class before
same idea I think
it's okay, uh so the key for the pumping lemma is that you find some absurd string that you can pump stuff into
just need to expand it a little
to make this choice of w have a length of a multiple of 3
im ngl Im still not sure how I would do that do I just add that |w| is a multiple of 3?
and keep the rest
well you want to take a different w
like your counterexample w will be different depending on the language
0^3n 1^3n ?
yeah
that's one way of doing it
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Hi I need some help on understanding a basic trigonometric identity:
(units are in degrees for simplicity)
sin(x) = cos(90-x) & cos(x) = sin(90-x)
What I am confused with is that this identity is different from the graphical interpretation of the sin & cos function. For instance, sin(x) is graphically = to cos(x-90) or the translation of cosine to the right by 90. However, cos(x-90) is different from the identity. Why is this so?
Appreciate any help
it might be easier to convince yourself that cosine is symmetric about the y-axis
I mean it is true
its true if you assume its true
what i mean to say is, if you can convince yourself of the easier evenness of cosine
evenness?
then this identity follows immediately from other things they already believe
an even function is one such that $f(-x) = f(x)$
jan Niku
cosine happens to be even
right
thanks
am i allowed to ask a follow up question or no, sorry im new
sure
abosulety not
ok
one sec i needa formulate
actually its rather simple:
sin function is odd, but the same identity confusion with graph holds for me? How can one explain this?
same identity confusion?
yes so
sin(x) = cos(90-x)
but graphically sin(x) = cos(x-90)
oh shoot
wait did I just
I'm not sure what you mean
isn't this the same problem as before?
what does this have to do with the oddness of sine
I mean, since cos(90-x) = cos(x-90) and cos(x-90) = sin(x) you can conclude that sin(x) = cos(90-x)

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is the way to solve this 5 x 5 x 2 = 50?
because the first digit can be any of the 5, the second digit can be any of the 5, but the last digit needs to be one of the two existing?
i feel like im missing cases where the second digit is the first digit and the third digit therefore can be any of the 5 digits, but i dont know how to show that in a formula
@dire siren Has your question been resolved?
i think when you go 5x5x2 you are forgetting that the first 2 numbers can be the same
i would go by counting the cases that 2 numbers are the same digit then when all 3 are the same
how would i show counting the cases where the 2 first numbers are the same?




