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need some help with this question
to me it looks like its going down?
then up at a certain point but still down first
@craggy owl Has your question been resolved?
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@craggy owl Has your question been resolved?
Hi! With graphing questions, it's kind of hard to tell (I will admit, this is a bad question). In any case, the point (-1, 2) looks a little further about.
yea...really dont like those graphing ones
If you look here, the point (-1, 2) seems to be on a concave up portion (i.e with respect to the x axis, since f_xx is the concavity of f by varing x).
So it seems that f_xx is more positive rather than negative.
interesting! do you have any suggestions how to do f xy of that point?
Well, fx tells me the slope along a certain fixed y. So, (fx)y tells me how that slope is changing as we move y, so I think graphically analysing that is the way to go.
I.e at (-1, 2), fx looks fairly positive, but what happens when shift y a little bit to the left or right? Does the slope increase or decrease?
sorry shift a little to the left/right in the y direction?
im a bit slow
we would be looking at the
fy (-1,2) is negative
and fx (-1, 2) also -
Welll
This is the tangent line to the surface at (-1, 2), right?
So here's the thing,
fx is the slope of the tangent line (in the x direction).
If we then take the derivative of this function (fx) with respect to y, what is this derivative doing?
how the slope in x-dir changes as we move in y?
Exactly.
So what that means is, we're still looking at the slope in the x direction, but we want to see how that slope changes.
Imagine that the blue and yellow points are just teeny tiny nudges of the red point in the corresponding y direction. What do you think happens to the slope as it moves from the red point (specifically from the red to the yellow point, since one-variable derivatives follow the positive direction)? Does it increase or does it decrease?
^ This is btw not a conceptual question, it's hard to tell from the graph.
yea...the point they chose is interesting
Ngl I think the slope ||increases. This is because the concavity (looking from the x direction) actually decreases significantly as you move in the y direction.||
Yeah bum question. Interpreting a 3D question using a 2D frame of reference is not that great.
I'm sure there's some arguments regarding saddle points that apply here or something.
But anyway, as long as recognise some logic like this, then I'm happy.
i just hope nothing like this will be on the exam
Hopefully so
i will ask a TA about this too but its an online course so i had this to go from
oh
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I would like to prove this
So I need to show $g \ker(\phi) g^{-1} \subseteq ker(\phi)$
wai
Let $x \in \ker ( \phi)$. Then \phi(g x g^{-1}) = \phi(g) e_{\overline{G}} \phi(g^{-1})$
wai
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
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you're welcome?
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Kind of confused
what do you think is confusing here?
so firstly, every element of the range need to have a pre-image?
"onto", yeah, I believe so
wait codomain
range by definition, every element has a pre-image
In that case I need to find all those combinations of elements whose product is 30
So the kernel would be 0,1, 2,3,5,15
Z_30 is an additive group btw
try using 1st iso thm
You have a surjective homomorphism
Also in this case if it weren't surjective it would be the trivial homomorphism
Yes
nice one
take the order of both sides of the iso
Lemme first justify this
Z_30 can be partitioned into 5 cosets
As for why
I think I'm forgetting some thoerm
ok so |G/ker(phi)| = |phi(G)|
From what I understood, the subgroups of Z_30 correspond to divisors of 30.
6
no 5
right
it's the image group
ok so |G/ker(phi)| = 5
and we know |G| = 30
do u know lagrange's thm
yea, I forgot that the converse is true for cylic groups
The possible generators are
why, to determine the elements of the kernel surely we want the cosets
hello, im new here, im interested in math so i joined here
we're trying to justify this first
ok, ill wait
lagrange's thm says that |G/ker(phi)| = |G|/|ker(phi)|
wasn't talking to u buddy 😂
!help
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Omg i thought you were talking to me 🫠
that follows as to apply the first iso theomr we want to map 5 cosets injectvely to this other group
ehh
u kinda need the fact that cosets all have the same size
which u get kinda used to and is easy to prove but really that's lagrange's thm
like lagrange's thm is kinda an easy thm
I know
I didn't realise you were askig for that 😭
?
ok so ker(phi) has 6 elements
and it's a subgroup of a cyclic group so is cyclic
we know 0 is in the kernel
therefore it must have a generator of order 6
yea, so 6 works
what are the order 6 elements of Z_30
yes and 6 is the only one
{0,6,12,18,24}
this is only 5 elements though
we need a genertor of order 5
each subgroup need to be of order 5
ah sorry i meant 5 is the only element of order 6
yea
no order 6
cuz ker(phi) is a cyclic group of order 6
{0,5,10,15,20,25}
got it
yep
why is there only 1?
Think what determines such a homomorphism uniquely
wdym by identity btw?
Identity map
Too much
not all bijections are homomorphisms though
No, everything to itself
Is there any efficient way to do this
Yes
and trivial means everything to identity?
homomorphism not ismorphism
I basically need to solve f(x+y)=f(x)+ f(y) modulo n
right
yes, but idt its useful to think about it like that
its kernel
maybe it would be best to start by constructing few explicit examples
can u find all the homomorphisms from Z4 to itself?
or at least some?
the homomorphism onto 0
so everything to 0, yeah, that works
what else?
can u find something less trivial
the identity is the other extreme
oh, as Z_4 is cyclic
the set of outputs will have a genertor
Z_4 can have cosets of order 1,2, or 4
Phi(0)=0; phi(1)=2
@spiral rock , "‼️ ". Is that wrong?
no, u're going in the right direction now
there are 4 such functions
Its ths key fact that makes this nice
I can't believe I forgot that , ( I've proven this too 😭 )
Okay, so the number of functions would be given by $\sum_{i=1}^{n} \frac{n}{\phi(n)}$
wai
so what should I be doing
Last attempt : Everything is determined by where 1 goes
thinking about examples of homomorphisms
1 has n-1 places to go to
you should just be thinking
it's not about computing things like an integral or whatever
I got it
you are in the wrong mindset
why? there is no reason why it should take you any particular amount of time to complete. you just have to get out of the mindset that "X problem should take me Y minutes" because that's not really how math works
like you discovered something about groups today that allowed you to find this trick of tracking where 1 goes
and the trick is simple but the discovery process is not
Tbf went through this same thing yesterday
was solving a functional equation for an assignment
took me 5 hours to realise a simple result would mean that no such function can exist
i don't understand what your point is
I know that I leanr a lot by taking time is my point
the sideroads can be more enlightening
yeah. if you complete a problem in 30 seconds and it takes you no effort at all then that's more of a waste than your functional equation problem
@twilit field Has your question been resolved?
why do we not like functional equations
i didn't say or imply that
Well, atleast now you have some facts to remember that may come in handy later on: Any morphism of a cyclic group is determined by where a generator is mapped
The answer to the problem is a consequence of the above simple fact, which you should engrave into your mind
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Is my understanding of implies correct?
(Here X means don't care/irrelevant)
(1 means true 0 means false for P / Q values)
@safe onyx Has your question been resolved?
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does this function have a vertical assymptote at 0
i mean it looks like it
by the defn u mentioned earlier, it does
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In this passage, is there a reason the author wrote one with brackets, and the other without?
No, just to emphasize where the sides of the original equation were
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should i find both the LHD and the RHD and make them equal or should i just try to find the limit definining the derivative
(i already got past the continuity part of this Q)
Just find the limit defining the derivative
nd what should i write before it
(as my reason)
"The derivative is defined as"
or something similar
"...defined as this limit"
or however your teacher usually writes it, or tells you to write it
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i used this fact
AB:DA = 2:3
then k:w = 4:9
well, its wrong
i think i assumed these are similar triangles
when they are actually not
but then i feel like they are similar
they have that shared vertical angle
anyways, im not really sure how else to approach this
Yeah they aren't similar
ABCD being cyclic gives you BCD = DAE = BAF, ADC = ABF, and ABC = ADE
cyclic means what? is that a synonym for inscribed in a circle?
Yes
interesting, i've never seen that before
Opposite angles are supplementary (BCD+BAD = ABC+ADC = 180º)
what's up guys i'm new here
General chat goes in #discussion 
how do i relate those angles to area though?
Well, there are similar triangles in the figure, find them
if i cut the quad in half it forms two triangles
but i dont think they are similar
i make this cut
but now i have no triangles that share two angles
same with this cut
Here, this is to scale, maybe that will help you find the similarities
Yes
that makes more sense
ok allow me moment now
ADE has sides 15, 3, 6 (out of order)
ABF has sides 2, (8/3), 2
huh
i got nonreal finding the area of ADE
No those side lengths are wrong
oh no
I don't think you need them anyway
I computed them to draw the figure but I don't think the question would require that
(I haven't solved the question yet, just waiting for you)
well, before we continue, can you explain why those sides are wrong
what i did was
BC/AD = EC/ED
and so on
to find each one
does BC not correspond to AD?
It's not EC/ED since BC and AD are not parallel
ah
Try imagining flipping the triangle ADE about the angle bisector from E
Then D goes onto EB and A onto EC, and that new segment is parallel to BC
oh
so i can use my side length strategy, i just have the wrong sides being compared
wait, i dont think that is possible though
Sure, but maybe thinking of areas is better
going back to this
i can relate the area of the big triangles to their smaller similar triangles
like A_CBE:A_DAE = 16:9
Right
A_CFD:A_ABF = 25:4
now i need to relate these two pairs
well A_CBA:A_CDA = 15:8
thats not the triangles im looking at though
oh lol
how do i relate these two ratios then?
sorry im kinda tired of math for today lol, maybe its obvious
Use r,g,b for the areas
Right
let me write as fractions so its easier to see it
$\frac{r+g}{g} = \frac{16}{9} \ \frac{r+b}{b} = \frac{25}{4}$
UCYT5040
there we go
i need to find b/g
$g=\frac{r+g}{\frac{16}{9}} \ b=\frac{r+b}{\frac{25}{4}}$
UCYT5040
That looks complicated
yeah am i overthinking it?
You should isolate r instead, to use elimination
$r=(\frac{16}{9}-1)g \ r=(\frac{25}{4}-1)b$
UCYT5040
Right
$\frac{7}{9}g=\frac{21}{4}b$
UCYT5040
now i can just undo cross multiply
hold on one sec
ok sorry im back
$\frac{7}{9}=\frac{21}{4}\frac{b}{g}$
UCYT5040
i get 4:27
answer key agrees!
thank you so much for your help!
this was the last problem i got wrong. and im not doing any more math for today lol
again, thank you!
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What is the logic behind putting numbers in brackets and not actually an equation?
Well some countries use BODMAS, some use PEMDAS.
so you’d kind of do “Brackets” or “Parentheses” before u multiply
sometimes its confusing just to have a floating negative, it can get confused for a subtraction sign
well in the case of this, there isn’t really any difference
^
Especially if you’re in exams and you get something like multiple negative signs..
well but i can write 3*-2 and still be correct
Why not?
you can yes,
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✅ Original question: #help-49 message
so whenever something is near brackets, you multiply?
Some say subtraction isn’t real
ik
Follow PEMDAS or BODMAS, whatever you’re taught
wdym?
There’s only ever negative numbers
whenever something is outside of brackets, just next to them, it signifies multiplication yes
WHAT IS THE DIFFERENCE?
No clue i’ve seen people arguing about it before
-2 is one symbol, it is the symbol such that when you add it to 2 you get 0
in general when you have variables next to each other too, its multiplying them, or a variable next to a number
2x=2*x
xy=x*y
okay but why for example -(-5+3) we switch them to +5-3, how does it make sense?
It so happens that the -1 symbol is special and you can rewrite the -2 symbol as the multiplication 2 * -1
distributive property
- signs can’t exist on their own, whenever they are by themselves it implicitly means there’s a 1 after it
so whenever theres a - or + i can add 1?
So here it’s (-1) * ((-5) + (3))
Brackets are there so that we can package a whole symbol into a “box”
but signs arent symbols
I did not say so for +
-(-5+3) is the 'opposite' of -5+3
“-1” is 1 symbol
when we add them together, we should get 0
It’s just 2 disconnected parts
but when you have 5-(-5+3), then you have to muplitply them by 5?
if it were -5(-5+3) we would multiply by -5
practically the same paradox as having said that all real numbers are complex itself because they have their Im(z) = 0
The only 2 properties you know about -a is
but if we had +(-5+3)
You would not write that
why is 1 and 0 so special numbers in math..
but the way you have written it would be read 5 minus the quantity (-5+3)
They are the additive and multiplicative identities
why don't?
Because the + symbol requires you to have things on both sides of it
0 is special because it doesn't change anything qhen it comes to addition but yet it changes everything when it comes to multiplication
$+2$ is as bad as $\frac{}{2}$
frosst
-something is just a quick way of writing -1*something
That’s technically not true but…
yeah so
5-(-2) = 3
It’s true in a field at least (ignore this if you don’t understand it)
and it's practically just a concept, hell I even had that straight thought once when I was trying to find out the proof for why zero is an integer, and why it's not just a concept, zero has a duality of being both real and complex, so many things make it special
yes, i know, but i think overcomplicating it now is pointless
No offence to anyone but I think we’re overcomplicating this for the poor op 😭
but they are classified as every other number..
This is 5 + (-(-2))
The - is attached to the (-2) object
And the - in here is attached to the (2) object
subtraction is just adding negative numbers
This is why I said some say subtraction isn’t real
yep...
yes but i think you could've just phrased it like that initially 😭
okay so - + - = -
I wanted the intrigue and delving into that thought..
Okay, well I wrote this for someone just now
You can’t add symbols together
Take a and b as any real number that you want. Then,
a + b = a + b. eg. 1 + 1 = 2.
a - b = a -b. eg 1-1 = 0
a + -b = a - b. eg. 1 + -1 = 1-1 =0.
a - +b = a-b. eg 1 - +1 = 0.
a * (-b) = -ab. eg 2 * (-2) = -4
But -a + -b = -(a + b)
why?
distributive property
think of it like this, you have 5 apples, and you owe 2 so you're in debt of a 2 apples (debt is the subtraction), now if they tell you that you're no longer in that debt, you actually no longer owe those 2 so you actually gain them to yourself, and gaining is addition, so you'd have 7 now in total
That’s just an axiom
We pick our maths so that it’s true
It turns out to be useful if we require it to be true
It somehow models something the real world does, and that’s useful so we pick it to be so
Like this example, maths wouldnt be very useful if it didn’t work
so if we remove the brackets, its -a + -b?
You can’t “remove” the brackets
the brackets are grouping it together
why? its two numbers
But you can distribute
You shouldn’t think of it as removing the bracket
You should think of it as the distributive property
so is it a single number?
a*(b + c) = a*b + a*c
The Distributive Law says that multiplying a number by a group of numbers added together is the same as...
This we take for granted
We just assume it is true
(Maths is based on a bunch of arbitrary assumptions that turn out to be useful)
but is (a+b) a single number?
Yes
but a + b arent
-(-a-b) how is this possible?
they are negative already
how can you already make them negative again?
like twiec
That is a shorthand for -((-a) + (-b))
We know that -a and -b are numbers, in particular they are the numbers which when you add it to a and b respectively you get 0
So (-a) + (-b) is addition between two numbers which (we assume) is again a number
This number also (by assumption) has its negative version
so is the minus glued to (-a-b) in -(-a-b)?
so if i wanted to add 5 i'd have to minus it with (-a-b)?
i once heard of this one thing from reddit or somewhere...
imagine you're standing looking at something in the right (positive, +) direction and your task is to turn around in the opposite (negative, -) direction.
if you turn around from the right direction, you'll be facing the opposite (negative) direction, if you turn around again, you'll be facing the opposite direction again but this time it'll once again be your starting right direction
every "turn around' and "opposite direction" is a -
every "right direction" is a +
Yes
5 + (-(-a-b))
kk.
You can somehow “unstuck” the - sign if you do -a = -1 * a
so this will result into 5+a+b?
so it will result into being 4+a+b in this logic?
But for addition we also require (a + b) + c = a + (b + c) so it doesn’t matter if you have brackets or not
No there’s a multiplication sign
It’s 5 + (-1 * (a + b))
There are a whole lot of brackets everywhere but we omit them for the convention of pedmas or whatever you learn it as
kk
okay
but what is the difference between podmas and bemdas
i was taught this:
()
x^2
.* / :
this is the usual order, these different abbreviations just use different names for each one
(), then ^ (right-to-left), then . : / (left-to-right), then + - (left-to-right)
for example 5 - 5 - 5 is seen as starting at 5, doing - 5, then doing - 5 again
5 * 5 / 5 does * 5 first then / 5
however, for 2^3^4, you start with 3^ then 2^
2^3^4 = 2^81
im confused..
which does what?
but in maths you do everything from left to right..
you don't do specifically one thing...
differently
sure because you use pedmas
lets ignore pemdas for now
Im talking about you bro
if YOU do 1 + 4^2, do you do the ^ or the + first
^
so much for left-to-right
whats the difference then
yes, you view this as 5, then + 9, then - 4
each operation you can view is something that takes an input number, does something to it, then leaves an output number
commonly this is read as starting at 5, then doing + 9 to it to get 14
this is technically different than just viewing + and - as operations that take two numbers together
but its more in line with the usual left-to-right that people actually do
if you do it like this, the operations themselves wont tell you what order to do them in, you have to decide on an order
but what if this
5 * 9 : 2
5, then * 9, then : 2
,calc 45/2
Result:
22.5
,calc 4.5*9
Result:
40.5
not the same result
4.5 * 5, no
be consistent with your inconsistency
also, this is an example where either way is correct
well in bodmas you do division first and PEMDAS you do multiplication first
Result:
22.5
i think you're starting to get aggressive.
I was just trying to mirror yours
like look at this
and you presented the example without even testing it first
Im trying to match your energy you know
as I was saying, theres a reason why PEMDAS or BODMAS isnt actually airtight
thats because of a common rule that usually people use to read the operations instead
the strongest operations go first,
well if you remove the brackets, it would be 3 - 2 and that can be mistaken as a minus sign
and with operations of same strongness, they are read left-to-right if they do actions
but divison and multiplication are equal
listen, please
no
yes
you can also see theyre of the same color here
compare that witht he brackets, order, and addition/subtraction
no you can't do any order..
wdym by that?
thats not what the "or" means
the "or" means neither of them are stronger than the other
the "or" means we have to use a different rule other than "multiplication first" or "division first"
the "or" is equivalent to using the same color background
it does not imply you can do them in any order
do not misunderstand the image to get 'extra points'
no one image alone can explain how we do things, ok?
Im right here you know, let me tell you what the reason is
if according to your logic, why does according to PEMDAS, you have to perform multiplication first?
that is what your logic is here
6 / 2 * 3
but here.. doing in any order will get you different results
yes, so heres the idea that we have
perform from left to right
the idea is that we stick to one way of viewing things, and we stick to it hard for consistency
this way isnt for "correctness" as much as it is for "consistency"
this is a key idea in math that often gets overlooked
why? How is that mathematically proven
consistency is more important than correctness
it's a rule we have to follow
we can't directly 'prove' it
well then prove for me that 1 = 1
look at it this way
so why don't bodmas and pemdas have the same order?
oval,
are you aware different countries do things different ways?
you know theres a U in colour in british english?
theres no "special reason" the u has to be there
well for the U in there, there actually is a reason, but thats besides the point
okay so i can decide if im going to do division first or multiplication
more often or not, changes happen and theres no good intentional reason for them
PEMDAS and BODMAS both communicate the same idea
it does, accent.
which is that multiplication and division arent done first
theyre just done left-to-right
by "special reason" I mean an intentional reason to insert the U in there
again, please dont misconstrue my words
accents are not an intentional choice
i get what you are saying
you seem to attribute some holier-than-thou status to the exact order of BODMAS and PEMDAS
oh... but so its american's choice to not speak british
that is not supposed to communicate to you the correct order
to tell you in simple terms
BODMAS
and PEMDAS
they all mean the same thing
the thing is that people call it differently
depending on their country
but mtt said it was different in the beginning
let me look at my exact wording
hmmm doesnt seem to place any one of them first
where is that message may i ask?
i think you misunderstood his words oval
then why did you say to start with the right side and then do the left side?
this is just telling you that its possible to get different answers if you do things the wrong way
he was saying what i said right here
first that he sent
well i can't just scroll up
oval, so far youve misconstrued two messages so far, can you actually reply to the exact message that gives you this idea
common misconception: people cant read your mind, you have to tell us in more detail what the confusion is
also frosst said that "whatever you learn it as" so i supposed that these are 2 different things.
oval thats not how you read that
the difference here could just be in how the same information is presented in two different ways
are you a mathematician or a philosopher?
yeah presented the way that the things had multiplication and division in different order
for example, color and colour are spelled differently, but they both mean the same idea
are you sure?
well, you can
its not muliplication or division first thats the rule
they said that parentheses should be calculated first
its multiplication and division, left to right, which is the rule
parentheses and brackets are the same word in american and british english
and since in the brackets, there was only a -2, so it means -2
consider for example -2^2
we usually do the ^ first, so -4
if on the other hand, you want to enforce the -2 is the number being squared, so -2 * -2,
you place parentheses around the -2
so (-2)^2 is 4
and as they said, if you remove your parentheses then it can be mistaken as a minus sign
no reason, its just that BODMAS is a popular way of viewing it, and BOMDAS is less popular
you know "order" isnt common in america right
we call it exponentiation
we dont call them indices
you may as well ask why neighbor has a silent "gh"
its not math, its history
how does that make sense?
but not list
well, according to PEMDAS, or BODMAS, we perform exponetitation first
now -x has a similar operation that is short for "0 - x"
it's not my rule
the rules arent very consistent, listen is just a counterexample
well but -x is a single number , not an equation
theres plenty of these around
and unfortunately for you, the - is a lot more separated from the number than you think
it is common to view -x^2 as -x * x instead of -x * -x
which is correct?
bold to ask
okay can you explain with the brackets and exponents
I just told you its common to view -x^2 as one instead of the other
shouldnt that be reason enough
-x^2 is more commonly viewed as -x * x
therefore -x^2 is consistently -x * x
this is a matter of convention, not correctness
do you know what convention means here? you seem to want to look for a right answer where there is only a consensus answer
if you want -x * -x, you do (-x)^2 to signify that the - sign goes first (called "negation" when used on a single number)
but ^2 is just a number being duplicated...
not true
^2 specifically means multiplying with itself
and in -x^2, whats being duplicated is x, since the negation operation - hasnt been done yet
-x^2
so (-x) (-x)?
(-x)(-x) and -x * -x are the same
yes
and they both mean x^2
but why is -x^2 not -x * -x
to remain consistent with the existing rules we already have
consider 0 - x^2 for example
If you look at 2x-4^2(3-(x+y))
would this really be (0 - x)^2?
what about 1 - x^2?
we view that -x should be the same as 0 - x
instead of being "the minus sign"
1 + x * x
this is so common that even if its attached to the number, we still put in ()s around it
for example, if I want to square -4 with itself, Id write (-4)(-4) or (-4)^2
I cant write -4^2
you can see here an extra () has been used, to denote that the - cannot be done last
operations have context
you cannot "regular expression" your way out of this
you cannot "string replacement" your way out of this
when you see a -2, it does not need to mean -2, it only means 0 - 2
and so -2^2 is 0 - 2^2, which is 0 - 4 or -4
the alternative is messy
This is really (2*x) + (-(4*4))*(3 + (-(x+y))))
lets say we view -2^2 as -2 * -2
But why have so many brackets when you can have a convention
but why cant you do -2 * -2?
now compare -x^2 with -(-x)^2
oval, look at what I am talking about right now
are you listening?
multiplication first than minusing with 0
youve just asked a question I am in the process of answering
you do realize that, right
as I was saying
lets compare -x^2 with -(-x)^2
show me an example of -2^2 and -(-2)^2
how do you calculate the both of these?
-2 * -2 and -(-2)(-2)
sure, because one is with a bracket
-2 * -2
however, see what happens if we test that here
-x * -x
for x = -2
you just calculated that x^2 = 4 for x = -2
-2 * -2
so what is -x^2
the same?
wdym the same?
now consider this
because two - is the same
what is x^2 - x^2?
you cant put like multiple signs like 5+++++++5
0
we actually can
well yes you can
but it's redundant
but we've just agreed that x^2 and -x^2 are both 4, didnt we
4 + 4 cant be 0
you wouldnt get an error if you used the negation symbol thats next to the enter key on the calculator
calculators only view a limited part of how we communicate math
go show me what happens if x is 2, and calculate each step out
x * x - x * x
isn't it?
x * x - x * - x
then, if x is 2?
that would be 8, not 16
try that again
unless
unless youre viewing it as (2 * 2)(-2 * -2)
what youve done here, by accident, is inserted an extra * in the middle of things
when previously the expression was x^2 - x^2
this is the main reason why we dont view -x^2 as -x * -x
2 * 2 * -2 * -2
im lost..
x^2 - x^2
x^2 = x * x
-x^2 = -x * -x
where?
here
4 * 4 is 16, 4 + 4 is 8
the x * x would just be 4
the -x * -x would be 4 again
if it was x * -x, thatd be -4
the other *s only get you 4s
so wheres the 16?
-x^2 is -1 * x^2, while -x * -x = -1 * x * -1 * x=1*x^2=x^2
2 * 2 (4) + (4)
moosey we're currently trying out an idea where the negator has greater precedence than the exponentiation operator, which has greater precedence than the subtraction operator
o
okay so can we get to the point?
ok youre gonna have to show me where thats from
how did -2 * -2 turn to 4 + 4
cause now we're making some extraordinary cofusing equations
.- and - = +
ok
-2 * -2 would be 4, not 4 + 4
yeah?
So expressions like -2 or -(4 + 3). Let's call it a unary expression
whyd you write 4 + 4 then
no you misunnderstood
It has a plus or minus as an operator
oh thats disgusting, I see
well dont invent new ways to write math in the middle of me trying out your idea
And to the left of it, it has no number, or at most operators
-2 * -2 is FOUR
2 * 2 is FOUR
(unary is actually a used term for that)
what is dusgusting?
if ou had to explain it, it isnt clear
what even is unary expression
in the middle of trying to be clear, youve used brackets, which are themselves a part of math
maybe you can say "which is"
2 * 2 (which is 4) + (which is also 4)
well but it was an example to show you
Let me explain this one to him
if you just write 2 (4), thats short for 2 * 4
I can try this one
you misunderstood here.
this time
oval, yes I did, and its still your fault because that was an ambiguous statement
(2)(4) means 2 * 4, its another way to write down multiplication
Hey, I can try explaining this but I don't have much time
im aware of that , i just wanted to show how it was done..
make the most of it
May I have your permission?
Alr thanks
So let's define a unary expression as this
It has an operator of + or -
There's no expression to the left of it
And it's right expression is exponents or parentheses
example?
-7
okay thats negative 7
Or +1
yep, not "minus 7" since theres no 0 to the left of it
when you use - in this way, its called a negation
-x^2 is also an example of a unary expression
so would - 7 be different?
We treat unary expression as a number
well we dont see a 0 to the left of it, so - 7 and -7 are the same
It makes no difference
youd need something on the left to see the difference: 0 - 7
0 - 7, 0 -7, and 0- 7 are also the same
So for example: -2 * -2
Since we treat -2 as a number, then we perform multiplication on both sides
yep, its 4
which equals to -2 and -2
Look at this definition
duplication of a number
Can someone help me with cypher ?
which order are we using, oval's version or the conventional version?
Look at this definition and think again
!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).
but if we did +5^2 then its +5+5
thats not how you read the + symbol here
^2 does not mean duplication in that sense
for example, if I did (1 - 1)^2, which would be 0,
would you really be doing 1 - 11 - 1?
thats -11
Try looking at this definition and calculate -2^2
but -2 is alone in there
try answering this question before they leave
I think I can give enough context for you to help
so its -2 * -2
-2^2 is a unary because to the right of it, there's an exponent
And we treat unary as a number
So to calculate a unary
idk what is unary
erm acktually
-2^2 = -(2 * 2)
if you wanted -2 * -2
it wld be (-2)^2 :3
You have to calculate the right one first
@sly cape @twilit jetty
Then perform what the sign says
yeah so unary = - 7 and ary = - 7
but -2 is a NEGATIVE number!!!
that doesnt really answer why you couldnt just do the -2 first, just that youre supposed to "not do that"
negative and positive number
I think I know what to answer this with
youre aware we are using two different kinds of - here
one for denoting a negative number
and another for subtraction
Use this definition to help him
now you think this one should go first, before exponentiation
oval, listen to me
it isnt two and then subtract
yes or no, you can see the two different operations?
one that takes in one number and considers it negative
yea
and another that takes in two numbers and finds the difference
but ultimately its the same purpose
no it isnt
it is
and its entirely for a reason you gave:
now so far, you are saying that because the - sign is part of the number, it shouldnt be that an 'outer' operator can just take out part of it
True
so for example, -2^2 should view the - first, so -2^2 is -2 * -2
unary expression
mhm thats my POV
however, by doing this, you are treating the - signs differently
consider -5 - 5 for example
BUT IN THIS EXAMPLE MINS IS WITH THE NUMBER NOT SEPERATED.
do you understand what i mean?
consider -5 as a unary expression
-5 + -5
if I wanted to multiply -5 and -5 together, how would I write it
-5 * -5
and if I wanted to add -5 and -5 together?
and you just said this, as a reminder
-5 - -5
so adding no longer places a + sign between numbers now?
wouldnt adding -5 and -5 be -5 + -5?
theyre both -5 and Im adding them
whats different here
thats subtracting
because the 2nd subject is a minus
That's subtracting -5 and 5
||Use unary expressions (it's a real term btw)||
this isn't right
it isnt, yes
thats because the way youre doing things isnt very good
we have a better way around this
adding -2 and -2 is
-2 - -2
||This is the last resort||
I think we've just stepped into a different kind of error that unary expressions arent going to solve
Lol
Yeah i see what's going on here
To add -2 and -2
Avoid confusion
Add the parentheses first
Should be (-2) + (-2)
Good luck!
ok Im going to show you something that you need to know beforehand
what do you think the + operator does?
fine
add?
you surely arent adding -2 and -2 here to get -4
youre turning the second number to always be positive then adding them
so if I were to start at -2, and try adding various numbers, Id get:
-2 + 5 = 3
-2 + 4 = 2
-2 + 3 = 1
-2 + 2 = 0
-2 + 1 = -1
-2 + 0 = -2
-2 + -1 = -3
-2 + -2 = -4
-2 + -3 = -5
any time I use the + operator, that is called addition
if the number we get is lower than before, it is still considered addition
in this case, we notice that adding a negative number makes you lower than before
does it simplify to subtraction? yes
but the initial step has used the + sign
-2 + -1
and will this result get closer to negative or positive?
not correct, oval
using the + sign is all you need to call it addition
signs do not care about the output of their result slanting a particular way
-2 + -1 is considered adding -2 and -1
-2 and -1 add to -3
-2 and 1 subtract to -3
-2 + -1 "negative 2 plus negative 1"
-2 - 1 "negative 2 minus 1"
-3 "negative 3"
and whats the point?
doesnt this go against what youre thinking
youre saying -2 plus -1 should be -2 plus 1 instead
even though thats not how the plus symbol is supposed to be interpreted as
all of these are the same
then why did you say this?
its -1 not plus 1
are you just saying -2 + -1 isnt considered addition because, when you simplify, theres a - sign?
yes as it results to -3 which is <-2
thats interesting, so whats the + sign doing there?