#help-13
428200 messages · Page 457 of 429
|g(x) - b| < delta_2
We WANT 0 < |g(x) - b| < delta_2
In order to use the last implication
so we need to ensure g(x) ≠ b?
yes.
Condition 2 says g(x) =/= b for small enough epsilon
then whatever mumbo jumbo we argued about yesterday
Hence, we can use that final condition and combine
delta_2 and t are unused so I chuck those quantifiers
$$(\forall\varepsilon_2\in\bR^+)(\exists\delta_1\in\bR^+)(\forall x\in\bR)$$
$$(0<|x-a|<\delta_1\implies|f(g(x))-c|<\varepsilon_2)$$
Shuri2060
And that's exactly the statement that lim (x->a) f(g(x)) = c
Me not assuming the deltas/epsilons were the same were kinda necessary (it'd be just incorrect to assume they are)
wait what
how can we combine
I am combining by substituting t for g(x)
Because we know 0 < |g(x) - b| < delta_2
Hence that last implication applies for t = g(x)
??
That's NOT the same as what you were suggesting earlier
$$(\forall\varepsilon_2\in\bR^+)(\exists\delta_2\in\bR^+)(\forall t\in\bR)(0<|t-b|<\delta_2\implies|f(t)-c|<\varepsilon_2)$$
Look, we had this
Shuri2060
If I just substitute t=g(x) into the entire statement I get
$$(\forall\varepsilon_2\in\bR^+)(\exists\delta_2\in\bR^+)(\forall g(x)\in\bR)(0<|g(x)-b|<\delta_2\implies|f(g(x))-c|<\varepsilon_2)$$
Shuri2060
That's just wrong
'for all g(x) in R', blah blah
No.
Here I'm not replacing 't' everywhere with g(x)
I'm only doing it in that specific statement, NOT quantifiers as well.
@gentle lintel You're like suggesting something like this
$$(\forall x\in\bR^+)(-\sqrt{x} < \sqrt{x})$$
$$(\forall x^2\in\bR^+)(-\sqrt{x^2} < \sqrt{x^2})$$
It's just wrong
wait how can we equate t and g(x) anyway
Shuri2060
aren’t they separate entities
I can't make a proper example, but I hope you get what I meant
yea so all this concludes all we need to know for change of variable shits?
I'm not really changing variables.
like the theorem
and its intricacies
yea
for the theorem?
i got both intuitive and algebraic understanding of that one fucking condition
and the entire theorem too
good for me i guess
Imma just save the chat (ヘ・_・)ヘ┳━┳
idk
no idea what u doing
If you can understand this quantifier whatever
And limits
You've already started analysis
Shuri, can you point out to all steps you used? to prove the theorem?
I'll rewrite ok
just the screenshots
lol
So the main argument that @jaunty mural made was we needed 0<|g(x)-b|<epsilon for x close to a .For that we needed g(x) not equal to b close to a
Hmm.. thanks ^^
First step is this. EDIT, I meant let epsilon_1 = delta_2
Then the statements can be combined so. (I guess I really mean for x sufficiently close to a)
Using the 3rd statement,
(getting rid of unused quantifiers)
Think that's it.
The statement was true for all epsilon
So picking out a specific epsilon = delta
is perfectly valid
This proof is infact is really similar to showing if f,g are cts so is f compose g.Here we needed 0<|g(x)-b| but there g(x) can be equal to b as well I think
Yes,it is a nice proof.
this is why we need condition 2
Yes, exactly
The limit statement does not include a '0 <' for continuity
Because we require the function to equal its limit at that point
one more thing

is the ε-N the ε-δ for infinity limits?
There is a different between sequences and functions
limits of sequences are foreign to me
By this, we're basically fixing all epsilon 1,2 and delta 1,2?
$$\lim_{n\to\infty}a_n = L$$
$\iff$
$$(\forall\varepsilon\in\bR^+)(\exists N\in\bN)(\forall n\in\bN)(N\leq n\implies|a_n-L|<\varepsilon)$$
Shuri2060
(defn of limit for sequences)
Using my previous example
f(x -> 0) : [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ...] (limit is 0)
g(x -> 0) : [1, 0, -1, -0.5, 0, 0.5, 0.25, 0, -0.25, 0, ...] (limit is 0)
(fg)(x -> 0) : [0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, ...] (limit is undefined)
f(x -> lim g) : [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, ...] (limit is 1)
You give me an open interval around L
I can tell you a point in the sequence after which everything is in that interval
For g(x -> 0) : [1, 0, -1, -0.5, 0, 0.5, 0.25, 0, -0.25, 0, ...] (limit is 0)
If you tell me to get everything between (-0.26, 0.26)
I give you N = 7
🤷♂️
rigorous definition of multi variable limit
or something
is this studied
or is it in 2 analysis courses
one for single var, one for multi var
This is a handwritten version of @jaunty mural 's proof.
Just realised I didn't substitute my deltas/epsilons properly
Forgot when rewriting the whole thing
Oh
Pretty sure I did the 1st time round
._. I was wondering why it looked scary
nvm I'll go about the whole discussion still anyways
including the visualization of limits
Well the proof idea stands even if I didn't write it with the right letters lol
something new to learn
Anyway,I got your argument from the chats .
👌
If you are familiar with showing composition of functions are cts then this is just an easy modification of that proof
no.. I mean the visualization thingy
this however should've been easy for me had I attended my analysis classes properly smh
I think considering g as 'how you approach' is the easiest
They won't teach you to visualise right 😅
Like they will teach you in Calculus
And tell you to forget that in real analysis
As we are supposed to write full rigorous proofs for everything
exactly
is why Visualization thingy was kinda cool n new for me :o
Anyways, nice to know your doubts been cleared @gentle lintel
visual math is cool
i’ve had worse, no worries lol
You will love Algebraic topology then I think
nvm I did substitute properly. It's just the 1st 'Let...' is off. Should be 'Let epsilon_1 = delta_2'
💤
modelling himalayas
alg topo is pretty good
Yeah,it was like the first course for me where I was asked to visualise things and draw pictures instead of sometimes writting proofs 😅. Visualising was like a requirement there.
i’ve had this channel on for like 14 hours lol
i should probably close it
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I don't know if this is the correct server to ask this question but it's about boolean algebra. I have X=ABC and I want to convert it into NAND. An example would be X=A + B = not(not(A)) + not(not(B)) = not(not(A)not(B))
I tried ABC = notnot(A)not(not(B))not(not(C)) but has no idea how to proceed.
I'd do not(not(not(not(ab))c))
As a final answer
Unless you're more interested in the process
Yes I would like the process, please.
I mean typically I'd just use the commonly known conversions between NAND, AND and OR
But if you wanted a visual process
Anything, I feel my brain is so pooped. 😫
I would say something like
ABC
=not(not(ABC))
=not(not(AB)+not(C))
=not(not(not(not(AB)+not(C))))
=not(not(not(not(AB))C))
I mean it's ugly and doesn't serve much purpose because it's easier to just directly convert it
But you can see a logical equivalence between the two ig
I see
Could you then remove two nots? so not(not(not(not(AB))C)) = not(not(AB)C)?
Or am I thinking wrong?
Well you could but you would then need a normal and gate
Assuming you only have access to NAND gates I think not(not(not(not(AB))C)) is the most simple
Oh I see what you mean
not(not(AB)C) wouldn't simplify to ABC I don't think
AB+not(C) would be as simple as you can get it
but then it would not be a NAND gate anymore right?
Yeah but I mean more in the terms of logical equivalence
Simplifying it just to see what it is without the nasty nand gate stuff
I am sure I am just being stupid. The problem I have is that NAND = NOT (A AND B), and I can't see that not(not(not(not(AB))C)) is a NAND, for example not(not(A)not(B)), I can apply the NAND to it and see that it is NAND.
For the single nots I'm assuming you're saying not(xx)
It's just way too long to write everything twice a bunch of times
yes
not(not(not(not(AB)not(AB))C) not(not(not(AB)not(AB))C)) is quite a bit less readable
Plus if you leave one nand input 0 it'll work as a not gate too
I can try to draw a schematic
That would help very much, Thanks! 
Ah I get it now
Epic
I missed the not(not(AB)not(AB)), but now I get it. Thank you very much!
Oh
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Hi! I need to create a function to draw a curve between two points, with a variable that will define how smooth the curve is. So if the variable is low, it will be a normal arc, but if it's higher, it will be more like a logarithmic curve. I thought using logarithms would achieve this but if I understood them correctly, there's only one base that will give me a curve between two specific points, right?
I could do with just a name or resource I can look into to find out how to do this
Is there an application for the problem
To get a better idea of the curves purpose
It's a game where a character jumps, and I will have variables for the height of the jump (so, the Y of the second point), the time in which I want to reach that height, (which will be the X of the second point), and the magic variable that will define the sharpness of the curve. The first point will be Y=0 and X=0. It would make more sense to refer to T instead of X, maybe.
I'm coding this to practice these kinds of things, that's why I want to do it from scratch
Yes, from 0 to Y which will always be positive
And the two points are always set?
Like if the jump has a smaller height it'll go just as far as far as the function cares
Just less curvy
Let me draw it, maybe it's clearer that way
Ok
Oh so it's not like x and y position?
No no, the actual X position of the character is independent
I'm using X here as the time
So I run the equation multiple times per second, inputting the time as X, and the magic variable which be a number that stays the same
And Y would be the output
Try sqrt(1-x^n)
If you're working with conic sections, it might be worth looking into eccentricity
hmm for the second point being 1,1 that formula does exactly what I want
I can multiply the output to match the height and time I need, that'll work!
thanks!
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i did all the others wiht a good understandning, but this one i put 3 and it says its wrong, but i am not sure what other number it would be
looking at the left side i see it bouncing back and forth but comes to 3
so
keep in mind you're not searching for h(5) but the limit of h when x approaches 5 by the left side
oh i just tried it, its does not exist but how?
so because its going back and forth we do not have a precise number?
ah
i see that makes sense
no probelm
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any idea how to start
@crimson sedge Has your question been resolved?
just here to say this looks like an interesting problem but i have no idea
this was from a test
like past test?
yea
step 1: Show that you can write A = pP+qQ+rR, where p+q+r=1
(in terms of vectors and stuff)
nah idk how to do that as well
alright step 0: Show that for any point X on the line segment YZ, we can write X=yY+zZ for nonnegative y, z that sum to 1
OwO I can give a hint...
scary intuition
Just saying, perpendicular distance of a point from a line is given as: $D(A(m,n)) = \frac{|am+bn+c|}{\sqrt{a^2 + b^2}}$
(ヘ・_・)ヘ┳━┳ but I'd rather you figure why this and how this helps
Ansh
can we just use coordinate geometry
like if m and n are the ratio
then just multiply by unit vectors then adding them gives
X=nY/(n+m)+mZ/(n+m)

@crimson sedge Has your question been resolved?
It should've been... but idk if Arkos read my hint or not
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is it possible to define a function that has the set of integers as the domain, but the rationals/reals as the image?
What do you think
@clever jewel Has your question been resolved?
that it's not possible, but I'm still curious
How do you construct the rationals?
Try thinking of how you can get some rationals with just a single function of the natural numbers
Being as simple as possible
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i did understand it geometrically, but idk how to write the proof
Uhh umm
perpendicular distance of a point from a line is given as: $D(A(m,n)) = \frac{|am+bn+c|}{\sqrt{a^2 + b^2}}$
Ansh
Ansh
draw a random graph and try to show the result geometrically or using coordinate geometry using the above idea
You just have to show now that
D(P) < max{D(A), D(B), D(C)}
yea that is what i failed at
idk how to show that for any line theres always a vertex who's perp distance >=any point on the figure
ehh
draw lines parallel to the given line
passing through the three vertices
and the given point P
You'll have 4 parallel lines + given line
now show that no matter whatever the placement of the given line is, there's always a line in these 4 parallel lines constructed that lies the farthest
and that's not the one passing through P
:o
@crimson sedge Has your question been resolved?
ah i see now
thanks for ur help 
Lol GL
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Hi, i have a problem : i have a space, and 3 points, O, A, B. I know the coordinates of the 3 points. A and B represent 2 corners of that cube, and O is that cube's center. Here's a representation i made in blender :
Now, i need to get about 20 points on every edge of that cube in orange
How to do that ?
@real tide Has your question been resolved?

I am confused by this question.
Hum ...
Perhaps you could detail the question exactly as it is.
It isn't an academic problem or anything i have to answer
It's for a programming personal project
@real tide Has your question been resolved?
I give up
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I've got a problem stating "There are 13 apples and 17 oranges. What is the chance of making a group of 4 where there are at least two apples?" I've tried doing $\frac{\binom{13}{2}*\binom{11}{2}}{\binom{30}{4}}$ , however the result is wrong. The correct way to do it is to multiply all possibilities in the numerator (i.e. AAOO, AAAO and AAAA). Why does my way not work?
mteXD
what is 11c2
- there is a typo, i meant 28c2 instead of 11c2
then there is double counting
i think
i will choose 2 apples, then 2 apples
this is double counted for all possibilities
uve not double counted every combination
when there are 3 or 4 apples you count these combos multiple times
ow i see...
kind of
ok but is there any shorter way to do it than to multiply all the possibilities (13c4 + 13c3 *17 + 13c2 * 17c2 )
or is this the only way?
@noble garnet Has your question been resolved?
@noble garnet Has your question been resolved?
ok i did some thinking i've got it now thx
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hello, i have a stats question that i need help with
I think I agree but 🤔
if we have 0 1 2
i am having doubts bc if u pick the 1st and 3rd number first, it would be 30 x ? x 30
they didnt specify which numbers get picked first?
010
012
020
021
101
102
120
121
...
it shouldnt answer in final answer
so if its 012, 3x2x2
If you consider this, then there are multiple cases
same, not same.
so i am just going to assume the simplest case and go from left to right
ok then i guess it should be 30x29x29
yh
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i need help with implicit differentiation
@midnight fractal Has your question been resolved?
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the x from the numerator never gets canceled so i dont see how the leading term would not approach infinity
i started by multiplying by sqrt(5x^2 + 7) / sqrt(5x^2 + 7)
what happens if you divide both the numerator and denominator by x?
oh
you dont have to multiply sqrt(5x^2 + 7) / sqrt(5x^2 + 7) btw
yes you can just start by dividing by x
sqrt(5x^2) not sqrt(5x)
after dividing by x
4x * sqrt(5x^2) / x = 4 * sqrt(5x^2)
$\frac{4x \cdot \sqrt{5x^2}}{x} = 4 \cdot \sqrt{5x^2}$
xdk1235
i thought you had to do /sqrt x within the square root
$\frac{4 \cdot 3 \cdot \sqrt{5 \cdot 3^2}}{3} = 4 \cdot \sqrt{5 \cdot 3^2}$
xdk1235
$\sqrt{x^2} / x$ is not $\sqrt{x}$
xdk1235
$\sqrt{x^2} = x$ so $\frac{\sqrt{x^2}}{x} = 1$
xdk1235
oh
eh that is slightly wrong ig
$\frac{\sqrt{x^2}}{x} = \frac{\sqrt{x^2}}{\sqrt{x^2}} = 1$
xdk1235
but you know what i mean
they specifically tought me that sqrt(x^2)/x approaching infinity you have to think about x as sqrt x which would mean sqrt(x^2)/sqrt(x) = sqrt(x)
oh
no you are right
i missed the square
so sqrt(5)/4
yes
thank you
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hey
@twin rose Has your question been resolved?
@twin rose Has your question been resolved?
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ABCD is a parallelogram and BC is produced to a point Q such that AD = QC.If AQ intersects DC at P, show that ar(BPC)= ar(DPQ) (figure given below)
i didnt get how to solve this question
Idk if im gonna be able to help, but @graceful sable where is Q
its the bottom right
oh yeah sorry its the bottom point i didnt take full screenshot
Ok
i dont remember geometry stuff too well
but im pretty syre i found this exact question on the internet
I dont know how much it will help you lol
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how to draw the graph?
'Hence'. You need to use part (a) to help you.
and is this a exam or smth
(a) only asks to prove the statement i dont think its usable in (b)
no its an exercise but we took the questions from other states' tests
@proven oak Has your question been resolved?
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What is the weight of 15.625 cubic feet of aluminum
type your query in lol
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I am more wanting to understand the why for this Question.
I am finding the Domain without graphing the function, I have gotten the answer and to make sure I am correct, I went to look at the answers, and its x <= 9/2 but I am not sure why its <=
I have gotten down to 9/2, but I don't know why its x <= 9/2
Can you find other numbers in the domain?
Its only 9/2 because I took the 'function' out of the sqrt and make it equal to zero, then got down to x = 9/2 but thats as far as it goes for me
the domain consists of those values of x for which your function is defined
and you want the stuff inside the sqrt to not be equal to zero but rather be greater than or equal to zero.
$9-2x \geq 0$ is what you should be starting with
Ann
Ohh thats where I messed up
Do you swap the sign when you divide by -?
Cause it ends up as -2x >= -9
I'm more wondering at which point within the problem does it switch to a <=
You do switch, but it's also easier to just add 2x to both sides
Right, okay, thanks for the clarification I was pretty confused on how it ended up as a <
But thanks
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I don't get how this problem works
15 cubic centimeters per second doesn't give me anything I could use in the volume formula (outside of setting v to 15, which doesn't really seem useful), so I don't know what else to do
dV/dt is given in the problem if I'm not mistaken
dV/dt is differentiating the volume equation with respect to time if I'm not mistaken
sills
@tidal crow
Volume of sphere..?
That formula's in the problem
dV/dt is 15 cubic centimeters per second
This is the information we know
I don't know how to find dr/dt from dV/dt, because 15 cubic centimeters per second doesn't give me anything I can use in the volume formula
@tidal crow https://www.youtube.com/watch?v=7tjarK_7cOQ
👉 Learn how to find the derivative of an implicit function. The derivative of a function, y = f(x), is the measure of the rate of change of the function, y, with respect to the variable x. The process of finding the derivative of a function is called differentiation.
A function is said to be implicit if the dependent variable is not explicitly ...
dt = the rate at which time changes
dV/dt=8/3pi*r^2
I don't see how this helps me
You didn't differentiate correctly
After doing power rule, you need to add dr/dt
wait wtf
how do you do this is if it doesn't give you r
lmao
You can't solve if it doesn't give you r
I have no idea either
If it said "find the rate at which the radius is changing when the radius is 3" then you could solve it
$\frac{dV}{dt} = 4\pi\frac{dr}{dt}r^2$
sills
Well, if I'm being honest, I googled it, and it does have a solution
It doesn't really make sense to me, but I could give you the solution they got if you want to look
What's the solution?
But that's how you differentiate
sills
Think I know where to go from here, gonna keep this open but I think I know
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Hello
I need help with q3
I’ve proved (x+2) is a factor
Dunno how to continue from there on
Aight gimme a sec I’ll try it
Thanks for da suggestion
nw
yes looks correct
But how do I apply the quad formula with an unknown tho?
it works just as well with an unknown
since you only need to find a range of possible answers
Oh ye you’re right
Man why didn’t I think of that lol
Thanks fellow Dave fan 🙃
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nw glad to help :)
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I don't understand what a) is asking for
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how do you solve 2 3 and 4 my teacher explanation was horrible
you could set up a general quadratic function
f(n) = an^2 + bn + c
and then solve a system of equations
i dont understand
How did you do 1?
Probably from the teacher's "horrible" explanation
you're given that's it's a quadratic, and that f(1) = a+b+c = 3, f(2) = 4a+2b+c = 12, f(3) = 9a+3b+c = 27, f(4) = 16a+4b+c = 48
so you have 4 linear equations in 3 variables - which you can solve
Using the info Ramonov gave, you have the general form of the quadratic. You also know the nth term. IE n = 1, you have 6. That's like a coordinate point. You need just three of them to plug in, you'll have 3 equations, 3 unknowns, solve for each unknown using elimination/substitution
btw in your f(2), where are 4 and 2 from?
my brain cant handle these tips
oh
please simplify
sub n = 1, 2, 3, 4 into a general quadratic an^2+bn+c
set each one of these quadratics to the nth term in the sequence you're given (hence why we stop at 4 cause you're only given 4 terms)
this gives you 4 linear equations in a, b, c
then solve for a, b, c using standard methods to solve simultanious linear equations
Example: problem 2. General form $$f(n) = An^2 + Bn + C$$. First term is 3, also written as (1, 3), where it is (n, f(n))
If n = 1, and f(1) = 3, then
$$3 = A(1)^2 + B(1) + C$$
dldh06
and what are a, b, and c?
This isn't your question that you asked, so why are you questioning the process?
simplifying it for that guy
it's perfectly reasonable to question the process
a b and c are what you're trying to find
they're the coefficients of the quadratic that give you that sequence
im questioning the process the way you are trying to help me is to complicated for my brain im only 14 i dont know half the terms you guys are using
no I guarantee you know all of them
just read it back slowly and follow the process step by step
you should know what a quadratic is
at this stage you should also know about basic substitution
and you should also know what a sequence is
ik what a quadratic is just not about substitution
well not what you guys are doing
how do you not know about substitution
dont know
I found this, maybe it will help you out, slightly difference process then what we're showing, but still gets to the proper answer
https://youtu.be/5NY6CpB2Mog?t=420
Quadratic sequences, how to find the formula for the n-th terlm, using the difference method.
Quadratic sequences of numbers are characterized by the fact that the difference between terms always changes by the same amount.
Consequently, the difference between "the differences between the sequence's terms" is always the same. We say that the sec...
what is the value of
x + 2 when x is 4?
its due in an hour ive been stressing with it for last couple days so i resorted to this server to help me
are you able to do
what is the value of
x + 2 when x is 4?
ye
what is it?
6???
yeah
so you do know substitution
ok then you know subsitution
ok
start with (whether you use f(n) or t_n is up to personal preference)
f(n) = t_n = an^2 + bn + c
and substitute n=1
and tell me what you get
what an^2 +bn+c mean
here, try this
an^2 + bn + c
is a general quadratic
ok
where a,b,c constants you want to determine
start with
t_n = an^2 + bn + c
substitute in n=1 and tell me what you get
this is not supposed to be a trick request
sorry i cant answer i have to go and submit my homework in
here are 3 steps you can do:
- 2a = second difference
- 3a+b = U2 - U1
- a+b+c = U1
*U2 and U1 are 12 and 3 in number 2
@sage merlin should be pretty easy now
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Did I solve it correctly?
@haughty warren Has your question been resolved?
I just wanted to do $\frac{2}{5} \frac{5}{2} 5x^{2}=2x^{2}$
Oh
JSGF
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Hello, I am a physics fist semester and have some difficulties in Analysis and linear algebra. Can someone give me some tips and resources to understand these topics better?
I just looked up resources on Google
3b1b does a good series on applied lin alg, a great way to intuit the ideas
Analysis is tough, keep at it.
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I am trying to find a horizontal parabola equation. I know the vertex (-9.5,0) and a point of the parabola at (-3.6,5.963), another point is at (-3.6,-5.963)
I have tried to input this into the y^2 = 4ax equation to find my a but with no luck.
So currently my equation to find 'a' looks like: 5.963^2 = 4a(-3.6+9.5)
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Are all sequences that converge to a limit cauchy?
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hi
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can i get a nudge with factoring this expression: 7x^3-7x?
do you know factor by gcf?
this is what i got when i tried to factor: 7x(x^2-x)
it didn't look right and i feel lost
yes i know factor by gcf
can i get another nudge? im still lost,
if you expand this
you get
7x³ - 7x²
chromium don't occupy many channel
note that factor is just reverse expand
none are being used
that one i closed
somehow still has my name
idfk why
XD jk
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Im not seeing it
thx
so you first factor by gcf
what’s the gcf of 7x³ - 7x?
7x(x^2-1)
what was that
do you know the difference of squares?
a little
what does it state
a^b-b^2 = (a +b) (a-b) i think
no
so in this diagram
we wanna find the area of grey
do you see how a² - b² and (a + b) (a - b) are equivalent expressions?
yes
so algebraically, they’re equal
a² - b² = (a + b) (a - b)
difference of squares yey!!!!
how
use this
(x^2+1) (x^2-1) ?
Without the squares
(7x+1)(7x-1)?
so we put it back here
(7x + 1) (x^2-1)?
we directly apply this result
on hood cuh imma juh become a rapper hit my partna nba youngboy up
thanks anyways jitt
actually gangsta before i get locked up from shooting a block and give it all up let me get help with one more
5x^4 - 80
this is where i got to: 5(x^4-16 = 5(x^2 +4) (x^2 -4) = 5(x +2) (x-2)
5(x+2) (x-2)^3?
wtf idk what i just typed
nah bruh i need a push in the right direction im stucker than a milf in a dryer
oh wait i see
its 5(x ^2+4) (x^2 -4)
yes
right @gentle lintel
no
5 (x + 2) (x - 2) is almost correct
but you forgot something lol
what i forget?
oh
5(x^4-16) 5(x=2)(x-2)?
omg i think thats the answer
i wont go rob anyone if thats it
ill quit the gang life
@gentle lintel
?????
what even is 5 (x = 2) (x - 2)?
oh i meant x+2
still no
you factor (x⁴ - 16) into 3 things through difference of squares
can you figure out what those are
we omit that for a sec
5
yea
whattt
how
i can only see two
what do you even mean by split into 3?
@gentle lintel
why only 1?
if you factorise one then it would be ((x² + 4)(x-2) right?
@gentle lintel
wdym
one of these you can apply difference of squares again
one of these you can’t
so only one can be further factorised
Hey @crimson sedge if your question has been resolved, type .close to free up the channel for other questions
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Had a problem exactly like this few minutes ago, and have another one. Tried to use the same method but don't see it going anywhere (factoring both numerator & denominator)
I don't have the definitive answer to it
@crimson sedge Well, 65536 is 2¹⁶ and 32768 is 2¹⁵.
are you allowed a calculator ?
are you expected to know that?
that 65536 is 2^16
that 65536 is 2^16?
doubt it
can't I somehow factor or agroup the numbers?
and simplify if possible?
because of course now that I know that 65536 is 2^16 and possibly all the numbers follow the same pattern it's easier
but certainly I wouldn't know that in a exam that I have 3 hours to complete
Chai T. Rex
Well, it's a bit cut off.
that's what I thought
it's okay
I was discussing with my friend that sent me this question
ty
No problem.
Yes, there are probably tricks to make it easier as well.
You'll get an integer times x.
I somehow doubt that it's the method
won;t it getg too convoluted?
or will it actually simplify
but considering
that I don't know the info that Chai said before
it's apparently the way
like I had a problem that had 3^x
I don't know log
It does simplify, but there may be an easier way that I haven't seen.
so the only way was to consider 3^x = y
actually I think thi sis the way
the trick is just seeins that the constants will cancel right away
but also, given that the answer is in the form of 2^16
you're probably expected to know that 65536= 2^16
so just slowly improving the equation?
but using this way wouldn't it come as powers?
well, I'm going to try it right now
You can probably expand easily with the binomial coefficients and then do a long division of the polynomials.
I don't think you have to
you can see that everything besides x^3 and x^2 will cancel each other out
then again... can see is not always the best argument
To avoid fractions with x/2 in the denominator if I chose x = 65536.
As to why I'd choose either 32768 or 65536, that's to make the things you add to it very simple.
oh I see, so divide by 2
okay
oooooh now I understood completely why (2x - 3) and all others
you choose a base, in this case 32768 and adding or subtracting depending on the number
I see, didn't thought about that
and another question
I could if I wanted consider x as 32767, right?
You could if you wanted to, but since the answers all have 2¹⁶ in them, it's not going to be pretty.
so the requirement for choosing it as 32678
as the 2^16
if I wouldn't notice that but still saw the pattern and consider some number as x how would I think for choosing the number 32678?
is there there another thinking process on it?
Well, you notice that the answer has powers of 2 in it.
Also you notice that the problem's numbers have powers of 2 in them.
Like the top has 65536 and the bottom 32768.
I see it
Not just even, but a power of two.
If you use 32767 instead, you'll get a(x + 1) as the result.
Instead of ax.
It just changes the result of the polynomial long division.
well I'm interested on how I would continue if I did that way
Well, you'd expand top and bottom.
Then you'd do polynomial division or factor both top and bottom and cancel.
but still I haven't solved considering x = 32768 so I will stop for a few minutes before that yet
uuuuh I think I got it
I've written all the replacement of the equation as x
could I immediately cancel some numbers?
If they're factors of the entire top or bottom.
If they're just factors of some term on the top or bottom, no.
actually I found a strange thing
why is there (x - 1)x + x(x + 1) ?
you would multiply it twice?
Because you had 32767 × 32768 + 32768 × 32769.
ooooooh sorry
Yes, because you had x twice in the original.
OK.
so on the denominator I thought of doing the \multiplications
x^2 - 5x + 6 (but as a result it came out as quadratic equation and I don't think this is the way you're expecting me to)
and I thought of too
No, that's the correct expansion of (x - 3)(x - 2).
forgot the comma
sorry
could I cancel the factors like
(2x - 3)^3
/ (x - 3)
certainly no, is that correct?
No, because those aren't factors of the ENTIRE top or ENTIRE bottom.
I see but can it be a + b / a + c
Only when it's a factor of the entire top and entire bottom can you cancel. Factor means multiplied by the whole thing.
and I can cancel them?
No, because it's added to the entire top and entire bottom.
But it's not multiplied by the rest of the top and multiplied by the rest of the bottom.
because I thought you can't cancel until there are + or -
No, you can't cancel unless you're multiplying something with the rest of the top and the rest of the bottom.
Chai T. Rex
That has a multiplied by the entire rest of the top, right?
Also it has a multiplied by the entire rest of the bottom.
b + c / d
Yes, if it's multiplied by the entire rest of the top and the entire rest of the bottom, you can cancel.
But it has to be multiplied by the rest, not added to the rest.
so that's what I should be searching in my equation now?
No, first expand the entire top and bottom.
The top has a trick.
The top is a bunch of terms that are (x + a)³ for some a (the a for the x³ term is 0).
So, expand (x + a)³ and then use that to do the hard work.
expand both (x - a)^3 & (x + a)^3?
by expand you mean
(x + a)^3 = (x + a)(x + a) -> quadratic equation multiplied by (x + a)
?
Yes, you can do it that way.
Is the most efficient way?
Yes, because you do the hard work of multiplying all that out once.