#help-42
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ok
*oh
right
so it would be
$\frac{\left(\lambda_0\right)}{16\ \epsilon_0R}\ $
$\frac{\left(\lambda_0\right)}{16\ \epsilon_0R}$
Why am. I here
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and this would be the y component too
There is no y component.
oh
The y component cancels.
so the other two quads have the same result I pressume
That was the point of this image.
yeah, forgot, sorry
Yes it would, you don't even have to worry about it. You can just use the bounds 0 to pi. And the result will be what it will be.
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hi, are my answers correct?
there's no second correct answer
okay
then the first one?
only the first one
<@&286206848099549185>
<@&286206848099549185>
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@glad sinew Has your question been resolved?
I'll send pictures of my work
but I think I got it
yea I gotta prove the other way for intersection
For (b) and maybe (c), have you tried finding counterexample? Maybe try a function with many inputs go to the same output, like {(1,2), (2,2), ...}
ok
Okie, lgtm for (a).
can you explain a proof for c)?
oh wait
atually i think its ok
ill send a picture after
for (<-)
if I already said y cannot be in f(B) even if x1!= x2, I can’t say there exist such x1 st y=f(x) in f(B)
so the last part is wrong..
I could say x1 in A intersect B..
@dull storm
can you check my answer for c?
Something's wrong in (->): even if $x\notin B$, it's still possible that $y \in f(B)$.
poypoyan
how should I write out (->) then?
so I just state that its still possible
abd hence it is a contradiction to f(A)\f(B)?
how come this is not true
but,
this is true
I did the proof, but isnt inverse basically in the domain and its function in codomain...
poypoyan
I'm sorry I have to write this again. May LaTeX is not that good rn.
You can do this for (c):
Here's a counter-example: Suppose $x_1 \neq x_2 \in A$ such that $f(x_1) = f(x_2) = c \in B$.
Let $H = {x_1, x_2}$ and $G = {x_1}$. Then $f(H \setminus G) = f({x_2}) = {c}$, but $f(H) \setminus f(G) = \ldots$.
poypoyan
but f(H)\f(G) = c still hold s true...
Nope, because f(H) = f(G) = {c}.
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could you help me please? i dont have much time.
i have multiply -8, 8, and 9 with the same number
so that it gets infintely many solutions
make the second equation identical to the first to make it redundant
yeah so a(-4)=-8 and b(-4)=9
no, a is 2 and b is -9/4
think about how you can multiply both sides of the second equation by -4 to get the first equation
oh yeah
i get it now
so 9/(-4)
is -9/4
?
that’s b
yeah
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Is this correct?
I don't understand german, but I assume it wants you to have the vector a + (1/2)b from point P?
Yes
Notice the direction of the (1/2)b vector you wrote, it has the opposite direction of b.
So you wrote a -(1/2)b
Direction matters. If you go north, then going south isn't going north, that's going the opposite direction of north.
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You're going in another direction.
What language
German?
I cant read
But it looks like i did it back in 7th
yeah but the b vector is minus, and i have to make it plus because it says +1/2b
can you go to a different help channel please?
here
Your b vector has its direction towards west-north. Then that's it. That is the positive direction of b, and you want that, (1/2)b is asked.
Like which one is which
huh?
Shorten your b, and apply it.
aah
west north is positive because it goes up
and not down?
but i think it is negative
because it is turned to the left side
Look at the arrow, that is the direction it's pointing.
b goes to the left
it cannot be a postive vector
i thought i need to make b positive
Beginning the linear algebra series with the basics.
Help fund future projects: https://www.patreon.com/3blue1brown
An equally valuable form of support is to simply share some of the videos.
Home page: https://www.3blue1brown.com/
Correction: 6:52, the screen should show [x1, y1] + [x2, y2] = [x1+x2, y1+y2]
Full series: http://3b1b.co/eola
Fu...
i know that i have to shorten it
Direction of its own matters, not the plane.
Watch this video, you'll probably get a more wider vision of vectors.
It wouldn't be easier to explain with words how a vector works.
in essence, you can't rotate your vector around without actual cause
you can only translate it (move it up, down, left, or right)
your 1/2 * b is okay
but your resultant (a + 1/2 * b) isn't
wrong direction
yes, that's better lol
thank youu
no worries-
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Can someone help me figure out how squared logarithms work
Squared logarithms don't have a property so try to do normal algebraic manipulations
Okay
But the last term has an identity: $log_8x^2 = 2log_8x$
Oğuzhan
Only the $log_8^2x$ doesn't have a property
Oğuzhan
Alright
,rotate
Okay
I got this so far
Is this right?
Well I don't know what to do after this
Also, am I allowed to cross multiply with inequalities
@glacial lily
<@&286206848099549185>
Sorry if you did not want to be pinged Oguzhan
I got it into one fraction
I am having trouble factoring the quadratic
I am stuck with this
@torpid vine Has your question been resolved?
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If f is surjective and g is not surjective then g o f is not surjective
Is this statement true or false?
@heavy spoke Has your question been resolved?
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$f(x) = \begin{cases} \frac{kcosx}{\pi -2x}, &\text{ if x } \neq \frac{\pi}{2} \ 3, & \text{ if x = } \frac{\pi}{2} \end{cases}$
MAN WHY DO I NEVER GET THESE RIGHT
Barbie
@tepid oriole Has your question been resolved?
<@&286206848099549185>
note x not equal pi/2 to means greater than or less than pi/2
yes i am aware of that
for some reason i have a feeling that this question is incorrect
think the question is wrong
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given f(x)=3^x-1 +2 as x approaches negative infinity
what happens to f(x)?
$f(x) = 3^{x-1} +2$
Barbie
is this what you mean?
i think it just equates to 2
how?
im an idiot
yea it most likely does
lmao
how did u get it tho?
i plugged in
i also plugged it in.
any other way?
well there is one other
f(x) = 3^(x-1) + 2
= 3^x * (1/3) + 2
= (3^x / 3) + 2
lim[x → -∞] f(x) = lim[x → -∞] ((3^x / 3) + 2)
= lim[x → -∞] (3^x / 3) + lim[x → -∞] 2
= (lim[x → -∞] 3^x) / 3 + 2
= 0 / 3 + 2
= 0 + 2
= 2
if you remember 3^-1 = 1/3 so the more negative the x-1 term gets the smaller it becomes so at negative infinity 3^x-1 is basically 0
we didnt learn limits
x approaches anything basically just means lim x-> whatever that is
but if you didn't just plug in.
it doesn't really matter.
this one makes sense
thx tho barbie
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Are there any shortcuts to knowing if something is a permutation or combination?
no
so the only way is to read it and analyze :/ there aren't any keywords or anything?
These questions can be extremely free and varied, sadly.
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yo
can someone help me with a question

so
i need to invert C
and C= A-2I
so my question is how do i get C ( i dont understand what 2I does)
I is the identity matrix
wdym
yea in this case C=A-2I
that right part just says that the C matrix is equal to the difference of A and 2*I
were you taught how to add and subtract matrices?
yes
then what exactly don't you get about the operation here
the thing is i learned it but i have forgot it ( i am currently preparing for a retest)
This precalculus video provides a basic introduction into addition and subtraction of matrices. It contains plenty of examples and practice problems on how to add and subtract matrices.
Introduction to Matrices: https://www.youtube.com/watch?v=yRwQ7A6jVLk
Adding and Subtracting Matrices:
ht...
incredibly trivial stuff
and should be the least of your concerns if you're diving into matrix inversion
i know this stuff
you just said you forgot it?
are you talking about inverting matrices or matrix addition
not what the video speaks about
i am talking about
when
it says A-2I
the 2I
what does that indicate?
do you know what the identity matrix is?
[100 010 001]
yes that's why I was so confused
[-2 0 0 ,0 -2 0 ,0 0 -2]
yea
i think when it comes to math
i always make harder then it should be
but thx for the help
i have 1 more question
if u can help me it would be the world
for me
yes
so it says The plane Π contains the points (−1, −3, 2) and (1, 0, 1) and is parallel to
lelt with the vector
a)give an equation for Π.
b) Calculate the distance from the point (10, 1, 1) to Π.
I believe the first thing is to construct an additional vector so that you can utilize the cross product
not sure how they got that vector from the 2 points because neither addition nor subtraction of one point to another turns p_0 into that
oh my bad I was looking at part a
let me test something out, I believe you dont need that specific point that your professor gave
I believe you can use either given point from the problem; let me try it first
oki
I get what your prof is doing but idk how they got the point, can you translate that second image
it does not say anything
just on the right side it say the point p0 is in the plane
what about the stuff before the final step
??
or u mean a)?
the shortest distance is given by
got it
you can use any point that lies on the plane using the formula they provided
I would use one of the two points that was given in the problem
so like (1 0 1)?
yes
uhhh okay
does that always apply like that?
or can there be a question where u need to find out?
as long as you're picking a point that satisfies this plane equation it will work I'm pretty sure
but yes if you have some layout like this, the equation for [distance from point to plane] that your prof provided should always work
np
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can someone help me with this? I am supposed to be asleep and i dont have much time
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Can someone just give me a hint for this problem (other than the one already given)? Or maybe a way to actually apply the hint that was given. Preferably just the first step or smth
Lol dw it happens
I think I'm actually supposed to use that tho, I just don't know how to get to that point
try putting it in the form (y+1)^2 for some y
its gonna be a couple of terms of (y+1)^2 for different y
Wait wdym by this
Oh nvm I think I got it
add and subtract some terms to have a polynomial that is of the form (y+1)^2 on the left side that uses the x^2 term
x^4 term*
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youre welcome
...
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can someone just lmk if I'm doing this right?
I've been absent with a cold and I can't take the test later because this is the last week of the quarter
you can't round the number when you start multiplying
because you get a different answer
oh shoot
okie
I couldn't find sin(40 so I just didnt round and it doesnt feel right
sorry for my hand writing xd
you should do it this way
because you see the circle part is confusing
Ill try to be more clear in the furture 👍

so im on the right track?
did you multiple sin 71 by 39.6 to get number like 40.165?
I gave you a clear step to restart again by multiplication
no problem
is this correct?
YAAAY
alr lemme continue to solve for the triangle then ill send you another screenshot
ooh alr alr
gn
hopefully someone else comes to my rescue
Now I would use the new angle I just in the law of cosine to find the last side?
@desert talon Has your question been resolved?
<@&286206848099549185> ?
@desert talon Has your question been resolved?
@desert talon Has your question been resolved?
.close
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So I’m trying to understand this but I can’t see where this magical covector is coming from
The claim is that a linear map is a (1, 1)-tensor
And he’s showing here that the notion of 𝚽 being a linear map that takes vectors to vectors is equivalent (in the finite dimensional case) to taking a vector to the dual of the dual space
He also claims that this output, that lives in the dual of the dual space, T( • , v), is something that can eat a covector, which maps vectors to reals
So suppose I have a linear map 𝚽
I can feed this map some vector v
What covector do I feed it to make it go to ℝ?
Because on the bottom left he writes that the T constructed from the data of 𝚽 maps a covector and vector to ℝ
By feeding the covector: 𝚽(vector) which gives a vector, which the covector clearly maps to ℝ by the definition of a covector
But I don’t get where this particular covector (denoted varphi) comes from

like the bottom left corner?
Ye
its coming from V*
Well yes it’s a covector it comes from V*
But where do I get this covector from
Say I have a linear map 𝚽 and a vector v
How do I make this covector
you dont make it
its any element of V*
T(φ, v) = φ(phi(v))
phi is the other phi 
So my 𝚽 can eat a covector and a vector and give me something in ℝ in a bilinear fashion
isnt phi a map from V to V
Ok my T_𝚽 can eat a covector and a vector and give me something in ℝ in a bilinear fashion
So from a linear map, I can create a (1,1)-tensor
Ah, and the top part is saying from a (1,1)-tensor I can create a linear map
Then the (1,1)-tensor and the linear map must be the same thing
theres a correspondence between the two
iso
Ah
So if I have a (1,1)-tensor and I give it a vector
Now it’s something that can eat a covector and spit out a real number
And this thing, has an isomorphic mapping to some vector v in V
So this thing is the T( • , v) object, which lives in (V*)*, and has a corresponding v in V by some isomorphism
And this corresponding v is what I’d have gotten if I just fed my original vector into 𝚽
But then it depends on the isomorphism I chose at this step no?
Yeah but you wanna think of the map the other way, you send v to T(-,v) and this will turn out to be an iso
Which is presumably why they're equals sign pilled
you usually don't
you're gonna need some kind of finiteness of basis argument here cuz its just straight up not true when V is infinite dimensional
You have to figure out that everything in the left vector space can be written as T(-,v)
In finite dim^
Well he did restrict to finite dimensional cases here
But this we can just get from considering the map the other way like above and show its an iso
you can probably pick bases and do linear algebra stuff to say that the map is uniquely determined by its values on the bases
and that'll give you the map back from V** to V
I’m trying to think perhaps say 𝚽 is a matrix right nice and concrete
Well then you definitely do have to pick bases
What sort of information am I getting out of the matrix such that I can feed it a vector and a covector to get a real number
Because T_𝚽 is saying we extract the information out of 𝚽
What specifically what information
if you have the matrix [phi] and the vector [v]
then [phi][v] is the image of v under phi
Sure
Indeed
but then like
That is indeed true
Ah
So in matrix land the covector is just the row vector of length equal to the dimension of V
Right because it is the thing that sends vectors to real numbers linearly
Hey that’s just the dot product
Kinda
So from the identity linear map, I can make the dot product
That’s the (1,1)-tensor that corresponds to the dot product
Once you choose (orthonormal?) bases yeah
just pick a new dot product
Oh right the dot product uses the basis as a definition
Hey but I don’t need it I can just slap some (w, v) into I(identity linear map)
And I get something that works like the dot product
Your T is essentially an abstraction of the dot product yeah
But its just the obvious thing you would do to get a number if you have a vector and a function from vectors to R: apply that function to your vector
Ok so if I have a function that takes a covector and a vector
Naturally I just feed the vector into the covector
But suppose I wanted to change it up a bit and include a linear map somewhere in there
Then I just feed the image of the vector into the covector
Yeah you can "twist" the map by some iso endo of V
But how do I know the image of the vector, is something that the covector can eat?
in some sense the isomorphism between V and V** is trivial when you talk about actual matrices
What if my linear map lost dimensions
[v] is also something in V** because you can do [w]^t [v]
It's need to be a map from V to V
Oh
Ah
That’s quite a strong restriction
So then not all linear maps are (1,1)-tensors
Only the ones from V to V
Otherwise like you say your covector can no longer in general eat something in some other non isomorphic space W
when you write (1,1)-tensors you kinda already mean like
V* x V -> R or something
but really like
Hom(V, W) and V* x W can be identified in some sense for finite dimensional spaces
For the V* and W?
I tried thinking about that but I didn’t get anywhere either
if you have an element [ \sum_i \varphi^i \tensor w_i \in V^* \tensor W ]
That’s a basis isn’t it
no it's just a general element
something in the tensor product is a finite sum of pure tensors
which are those phi x w thingos
you can associate to it a map in $\Hom(V, W)$ by doing something quite similar [ T(v) = \sum_i \varphi^i(v) , w _i ]
Are tensor product like a product topology
just feed the phis the v and multiply by the corresponding w
no not quite
but also kinda
You don’t just append the W part onto V?
Ok I’m reading Wikipedia and it says
Tensor product of V and W is a vector space with a bilinear map
It maps (v, w) to v tensor product w
In a bilinear fashion
I changed up the words a bit
the bilinear map is ${-} \tensor {-}$
it's kinda tautological
Right ok nice
So Hom(V, W) is just a vector space of all linear maps from V to W
And V* tensor product W is
Something
So it’s like you take a row vector length dimV, and a column vector length dimW
Ah you can make a matrix out of that
That’s the linear map!
Ok but I lose all sense of control when I’m forced to give up the notion of a matrix, a row vector and a column vector
it looks so gross
anyway
now when you get a vector
its gonna be like
,, \sum_i \mat[b]{|\ w_i \ |} \underbrace {\mat[b]{- & \varphi_i & -} \mat[b]{| \ v \ |}}_{\text{some number}}
so if you think of the w_is as the basis of W
that will somehow be able to give you any vector in W
What is this
my shitty representation of what [ \sum_i \varphi^i \tensor w_i ] is supposed to be
Ok so this is what anything on the right side looks like
Right side of this statement
And supposedly it represents a linear map because that’s what Hom(V, W) contains
well heres how the linear map works
So varphi_i is kinda telling me how much of my v gets turned a particular basis vector of w_i
yea

perhaps what you want is something more like
[ \phi : V \to W, \qquad T : W^* \by V \to \R ]
well the way im thinking of it is like
WAIT NO HE DID SAY SOMETHING LIKE THAT
something about “throw something on the right to the left, and give it a star”
and W** is meant to be W
“And works the other way too”


Where is this from
like
T : W* x V -> R
but instead
you can just give it a v in V
and you're left with a w in W* to give
Ok suppose T is such a map
If I give it a v, then it now looks like T(v) : W* -> R
T(-, v) : W* -> R
Ah but this T(v) is in (W*)*
The?
canonical one
I don’t know what’s the canonical isomorphism
its the substitution map
v -> (phi -> phi(v))
aka the do nothing map on column vectors
[v] -> [v]
since [v] is a column vector, and its also a cocovector since if you take a row vector [w]^t, you can do [w]^t [v]
So you’re saying a cocovector takes covectors to R
And in particular, [v] is a cocovector because it takes the covector [w]^t to R by [w]^t [v]
yeah
Ok sure
So then if I have T( • , v), this cocovector is canonically the vector v
And if I fed the cocovector T( • , v) some covector w
well here you actually want to apply phi first
yeah okay
But suppose I wanted to construct a particular T from a linear map
Then the cocovector T_𝚽( • , v) is canonically the vector 𝚽(v) which lives in V
Hmm, but I don’t know that 𝚽 is full rank, what if the image of 𝚽 is not all of V
Then if 𝚽(v) = 𝚽(w), for some v,w ∈ V, I have that T_𝚽( • , v) = T_𝚽( • , w)
Ok sure I just have less cocovectors
And clearly the different cocovectors I have depend on the 𝚽 so it seems like at least some of the information of 𝚽 is indeed getting passed on to T
If I feed my cocovector a covector, I just apply the covector to my 𝚽(v)
And that’s why he write 𝚽(varphi(v))
Ok
And the idea is that a linear map 𝚽 bring v in V to 𝚽(v) in V
But this 𝚽(v) has the capability to be fed into a covector
So it is in a sense a cocovector
So I get out something that can take a covector and get into R
So $V\overset{\phi}{\to}V\overset{v^\in V^}{\to}\mathbb R$
Frosst
So a linear map is like
Unfinished
I can still feed the result into a covector
Ok this is quite clear now, assuming I’ve not got the wrong idea in my head
Alright I will now roam freely with this new delusional idea
Thanks snow and zac 
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can someone explain me this
the content in the brackets is (x^2 + 1)^2 right? but why did x^2 change its sign
add and subtract x^2
What do you mean by changing its sign?
x^2 was rewritten as 2x^2 - x^2
why
So that you would have x^4, 2x^2 and 1 in the sum; Those add up to (x^2 + 1)^2
it's a trick to factorize x^4+x^2+1
we add x^2 so it becomes x^4 + 2x^2 + 1, then to balance it we subtract the x^2 we added
to keep it equal?
which becomes (x^4 + 2x^2 + 1) - x^2
yes
and now you can see it's a a^2 - b^2 form
cuz that left side quantity is square of x^2+1
so the step between those 2 was (x^4 + x^2 + x^2 +1) + x^2 and then to keep it equal it comes down to (x^4 +2x^2 +1) - x^2
yeah
which is (x^4 + x^2 + 1) which is (x^2 + 1)^2
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wait
isnt x^4 + x^2 +1 after subracting it what i started at :/
yeah we dont subtract it again obviously
this is what you have
now use (a+b)(a-b) formula
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How can i simplify this easily
@woven wigeon Has your question been resolved?
Break it into their respective prime factors
15 = 5 * 3
6 = 2 * 3
10 = 5 * 2
21 = 7 * 3```
Then exponentiate each appropriately and then simplify
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i used a calculator, and i think its right
i have 2 questions
- is it even correct?
- how would you solve this without a calculator?
You need a calculator.
ok that makes me feel better
x > ln(sqrt(63/7))
Yeah and whatever your calculator gives is the answer
If that's it then your answer is correct
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convert 0.281 to a fraction (81 is recurring)
just let x = the number
and try cancelling out the recurring part
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I am having a hard time understanding how to evaluate these functions I have tried to teach myself and haven't made any sense of these.
what does the graph serve in understanding how to evaluate the functions?
The graph shows you which values the functions take at different values of x
so at -1 f(x) is at 0 and g(x) -2 in terms of the y axis or is this not relevant?
Correct. f(-1) = 0, and g(-2) = 0
So for the first question, (f+g)(-1) = f(-1) + g(-1), can you tell me what that is by looking at the graph?
Im sorry I am confused.. Am i looking at the difference of the to graphs? If so the difference is -2
Correct. (f+g)(-1) = f(-1) + g(-1) = 0 + (-2) = -2
so then i am using the (-1) as a reference to see on the graph of where they are talking about and then seeing what the difference is. are we setting the function equal to zero to find the answer?
In part two the answer would then be 0 as there is no difference?
Also how does the function (f+g) , (g-f), ((g)(f)), (g/f) affect evaluating?
Let's make sure we know what a function is first. A function f(x) takes a value x and maps it to the y-axis in this case (see y = f(x)). So, for example, if x=-1, then f(x) = f(-1) = 0, as you can see on the picture
The first question states: (f+g)(-1) = ?, and you're supposed to answer what ? is. (f+g)(-1) is a syntactic way of writing f(-1) + g(-1), i.e., it's the same thing.
The second question states: (g-f)(-2) = ?, which is the same thing as g(-2) - f(-2) = ?
You have correctly answered that the second question is g(-2) - f(-2) = -1 - (-1) = 0
Does it make sense?
sorta.. so in i could view however they put g and f in the syntactic way as basically saying = and not be hyper focused on it as its going to not effect what i am seeing on the graph? cause (g/f) (1) would be 1/1 right?
(g/f)(1) is -4 in that case correct?
Make it easier on yourself by writing out the whole thing. (g/f)(1) = g(1)/f(1) = ?
Bravo. Correct
ahhh I understand this now the function is saying the rule that you are going to use to evaluate but also where on the graph you will be looking on the graph and the once you find the (f) and (g) you can then use the values from the graph to get the solution
correct?
Correct.
First evaluate f(-4), then take the answer you get and plug it into the g function
So
- let f(-4) = z
- look at the graph to figure out the value of z
- when you have the value of z, look at the graph to find the value of g(z)
so (f(-4)) = -3
Correct. You have figured out steps 1 and 2. Next, do the third step, i.e., evaluate g(-3)
Wouldn't that mean then that (-1(-3)) as g(-4)=-1 so then the solution would be 3
Where are you getting (-1(-3)) from?
Yes, it seems you are thinking about it wrong.
g(f(x)) is a two-step process. First, you evaluate f(x). Then, you take the answer you got from f(x) and plug it into g
So you've correctly figured out that f(-4) = -3
The next step is to evaluate g(-3)
then you have the answer
That makes more sense now
👍
Thank you so much I was so lost and didn't understand any of this you definetly helped me understand how to solve these correctly
Glad to help!
last question on this
As far as ((g)(f)) would be the same as ((f)(g)) as its just multiplication but just switching around g and f right?
Yes
f ∘ g is usually denoted as function composition, so (f ∘ g)(0) = f(g(0))
and (g ∘ f)(-3) = g(f(-3))
This should be defined wherever you are learning this from
... Now I am more confused
Oh is it saying it similar to how g(f(-4)) just written different?
It is the same but written differently, yes
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Hey I need help soling this fraction. I would appreciate if you showed how you solved it.
Im not sure where to start
the numerator? Im sorry im not fluent in english
hm
im not sure how
we can probably do soemthing with the "b" to start
no we cant, the other Bs multiplied
how did the 2 from the first line turn into a 4 in the second?
yeah, but why did that mulitply and not the others
So 4 x a square x b
They did
oh lright
just to make it match with the other side?
im sorry, I dont understadn where the second B went in the second line
hello? If you went away you could tell me, so I could ask someone else
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how do you find the tanget line
what kind of operation do you use to find tangent lines in other contexts?
y - y0 = m (x - x0)
so in other contexts, you find a tangent line based on a point and a direction. what kind of operation gives you the direction of a tangent line?
Yes.
uh you dont need the second derivative anywhere right
Not to calculate the tangent vector, no.
whats the point?
because r(pi/4) is ust one value
and this needs x0 and y0
oh wait
sorry im stupid
bruh
its a vector
sorry im really tired
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hi
i was wondering
if there is an alternative more elegant proof than i already did
i will state the problem
translation is show that the number c = .... is a perfect square
now my proof consists of taking an natural number(any number works) and seeing the general rule
complementary combinatorics
so you get
lets say n = 2
you get
C(5,1) * C(5,2) * C(5,3) * C(5,4) * C(5,5)
now
heres where things get nice
wait actually
maybe no
t
yeah it is
so
C(5,1) is 5, C(5,2) is 10 , C(5,3) is 10, C(5,4) is 5 and the other one is 1 which doesnt matter
now
10 * 10 * 5 * 5 = 2500 sqrt(2500) = 50
so perfect square
now from that
i just generalize for C(2n+1,k)
i showed that the rule still holds because using complementary formulas ( C(n,k) = C(n,n-k))
that's how i proved it
now i was wondering if there is a more elegant way of doing it
you COULD also
do
something like this
let me upload it wait
yeah something like this works good
and still a proof
since the first is equal to the one at the end
and there are 2n combinatorics in total
then there will be n pairs
so that will result in perfect square
that's another good proof i think
what are your thoughts?
@remote mural Has your question been resolved?
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Is the answer to this c?
@twilit bramble Has your question been resolved?
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Am i correct?
dude its the same question
yes
nice thx
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Joint Variation: One variable increases (or decreases) along with two or more others, all in the same way. More of one thing means more of another (and vice versa).
Combined Variation: One variable is affected by a mix of increases and decreases from other variables. An increase in one thing might be countered by a decrease in another.


