merry nacelle
No
#help-13
cedar kilnBOT
@merry nacelle Has your question been resolved?
marble ermine
Let ( V ) be a real vector space. Every subspace of ( V ) is a subgroup of ( (V, +) ).
wraith daggerBOT
lilisworld
marble ermine
is that true or false?
ok thanks
and
Every subgroup of ( (V, +) ) is a subspace of ( V ).
wraith daggerBOT
lilisworld
marble ermine
is that true or not?
south tundra
E.g., consider R as an R-vectorspace and its subset Z
marble ermine
ok
south tundra
Z is a subgroup of (R, +) but not a subspace
cedar kilnBOT
cedar kilnBOT
Available help channel!
stone gate
Hi guys! Can someone please tell me where I made mistake in this???
mortal wagon
the arctan formula only applies if a is constant
cedar kilnBOT
cedar kilnBOT
Available help channel!
coarse rock
Mae Carol Jemison, the first black woman to travel into space, writes books about space for children. Her agent is selling copies of her latest book, Mae Among the Stars, on an online marketplace. She currently charges $13.30 per book and sells 824 books every yearWhile experimenting with the price, the agent estimated that for each $0.05 increase in book price, the number of books sold decreases by 4
How do i find the revenue for that
I need to write a function for the revenue where x is the number of books
steel cloak
Are you sure that you are not asked to find the revenue as a function of the price?
coarse rock
revenue as a function of BOOK price
steel cloak
Okay
coarse rock
steel cloak
I would start to find an equation relating the number of books to the price
coarse rock
book * price
steel cloak
That is one equation we need, but we need another one.
coarse rock
Its alright i am done working on that
steel cloak
If the author sets the price to 13.30+0.05x, what is the number of books sold? [edited]
coarse rock
824
steel cloak
Perhaps you used x as the number of books. I meant like, x could represent how many notches of 0.05$ we have increased the price.
So like, if x=20, we increase the price by 0.05*20 dollars
We can write the price as 13.30+0.5x. Using the information in the text, how can you express the number of books in a similar fashion?
cedar kilnBOT
@coarse rock Has your question been resolved?
coarse rock
We can write the price as 13.30+0.5x. Using the information in the text, how can...
824-4x
steel cloak
fantastic! Now you just have to combine price=13.30+0.05x and books=824-4x to express the number of books in terms of the price
Here is how you can start:
price = 13.30 + 0.05x
price - 13.30 = 0.05x = x / 20
20(price - 13.30) = x
cedar kilnBOT
@coarse rock Has your question been resolved?
coarse rock
Here is how you can start:
price = 13.30 + 0.05x
price - 13.30 = 0.05x = x / 2...
[Books-824]/4=x
20(price-13.3= [books-824]/4
steel cloak
Great!
coarse rock
🙂
steel cloak
Remember, we want to write books * price in terms of only the price
steel cloak
Well, just like we sovled for x previously, we can solve for books.
coarse rock
Why didn’t we do 13+0.05x*[824-4x]
steel cloak
20(price-13.3= [books-824]/4
from this equation that is
coarse rock
20*4(price-23.3)+824= books
coarse rock
That is all?
coarse rock
Minus?
steel cloak
20*4(price-23.3)+824= books
according to this, the number of books increases with the price
coarse rock
Right
steel cloak
It should be 824 - 20*4(price-23.3) = books
coarse rock
Where did we get the - from
steel cloak
books = 824 MINUS 4x
coarse rock
Ah
coarse rock
books = 824 MINUS 4x
Amazing thanks
steel cloak
np, great work!
coarse rock
.close
oak anchor
does anyone know what's wrong with my program?
cedar kilnBOT
does anyone know what's wrong with my program?
oak anchor
I have to compute that
cunning drift
I dont now sorry
oak anchor
prepa économie
oak anchor
si je suis sur ce serv c'est que c'est le cas jpp
cunning drift
ok
dull oxide
your method names could use some work, for starters
cunning drift
Quels sont les principaux facteurs économiques qui influencent les décisions de politique monétaire d'un pays, et comment ces décisions peuvent-elles avoir un impact sur l'économie nationale et internationale ?
oak anchor
your method names could use some work, for starters
what does that mean? I'm a beginner in Python
oak anchor
Quels sont les principaux facteurs économiques qui influencent les décisions de ...
la réponse c'est Keynes
dull oxide
what does that mean? I'm a beginner in Python
It means that fuck is not an excellent method name.
cunning drift
de quoi
oak anchor
It means that `fuck` is not an excellent method name.
yeah I didn't mind naming it like that, is it a problem?
cunning drift
En utilisant le modèle d'équilibre général, explorez en profondeur les implications de l'ouverture des marchés internationaux sur la spécialisation, la croissance économique et la distribution des revenus dans un pays en développement. Discutez des avantages et des inconvénients de cette ouverture pour l'économie nationale et les divers acteurs sociaux?
oak anchor
En utilisant le modèle d'équilibre général, explorez en profondeur les implicati...
t'as trouvé ça où toi
oak anchor
mes dissertations de 12 pages sont pas aussi exigeantes stp
crimson sedge
si je suis sur ce serv c'est que c'est le cas jpp
Généralement les personnes sur ce serv aiment pas trop les maths et veulent juste de l'aide
cunning drift
a dsl
@oak anchor Comment l'offre et la demande de travail influencent-elles les fluctuations du taux de chômage dans une économie et quel rôle joue la politique gouvernementale dans ce contexte ?
crimson sedge
does anyone know what's wrong with my program?
I don't see how the code has anything to do with the question
cunning drift
@oak anchor alors
crimson sedge
does anyone know what's wrong with my program?
After looking at it for a bit more, it looks like you meant to write u(y,n) instead of u(y,x) on line 16
Welp I'm out
oak anchor
I don't see how the code has anything to do with the question
Actually I managed to simplify it and I got this
but there's still an error
mighty drift
I have to compute that
mais encore ?
mighty drift
Actually I managed to simplify it and I got this
fridge c'est mieux oui
Mais main reste plus conventionnel
cedar kilnBOT
mighty drift
mais encore ?
c'était pas théorique à la base ?
oak anchor
c'était pas théorique à la base ?
comment ça
mighty drift
généralement une Q de maths c'est pas de la programmer
c'est trouver la limite, un DL, une forme explicite, des choses comme ça
cedar kilnBOT
Available help channel!
crimson sedge
cedar kilnBOT
crimson sedge
im 99.9% sure im correct but my paranoia is not letting me go forward without double checking
mighty drift
that's why we invented calculators
crimson sedge
that's why we invented calculators
yes
mighty drift
well it's not why, but it's still usable for that purpose
crimson sedge
well it's not why, but it's still usable for that purpose
yeah sorry for hogging up the space
.close
cedar kilnBOT
mighty drift
yeah sorry for hogging up the space
there's also #bots for that
because that's also wolfram alpha-able
though at your level, any computation is
crimson sedge
though at your level, any computation is
yeah I know let's just forget this ever happend
.close
crimson sedge
oh ok
mighty drift
it just auto closes after a random amount of time
crimson sedge
it just auto closes after a random amount of time
well i got another question i want reaffirmation on
crimson sedge
it just auto closes after a random amount of time
also
the exponet is -2 right
so i just write -2
mighty drift
you can do these. You don't need to ask for all of them
cedar kilnBOT
Available help channel!
vivid fog
Hi there, I am studying proofs myself to prepare for my later courses, in the textbook they left the exercise of proving the attached proposition. I am stuck with the case that x is negative and was wondering what is my next best step.
Thank you for taking the time to help 🙂
vivid fog
Wait actually, can we just say that root x^2 will always be positive because any number squared is positive and we can't square root a negative number, which in turn makes the absolute value of x = x instead of -x?
<@&286206848099549185>
cedar kilnBOT
@vivid fog Has your question been resolved?
vivid fog
<@&268886789983436800> can I ping again
floral sinew
Yes - this is covered in #❓how-to-get-help
floral sinew
Np - please have a look next time before pinging eveyrone though lol (seems funny pinging lots of people to see if you can ping lots of people xd)
cedar kilnBOT
@vivid fog Has your question been resolved?
raw star
cedar kilnBOT
raw star
Hi can I get some help on this question
exotic furnace
!status
cedar kilnBOT
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
@raw star Has your question been resolved?
raw star
@exotic furnace I am at 1
exotic furnace
well, 0<a<1, right?
raw star
Yes
exotic furnace
What’s the range of a^2 then?
exotic furnace
Yes
raw star
But what would I plug into the function
exotic furnace
What’s your x
exotic furnace
Can I put like any negative number in the range there?
No, you don’t know what a is
So just put it in terms of a
In other words you’re plugging in -a^2 everywhere x is
exotic furnace
U get like -a^6-2
Yes
raw star
So is that all I have to do? Sorry for late reply
exotic furnace
So is that all I have to do? Sorry for late reply
Yes
cedar kilnBOT
@raw star Has your question been resolved?
cedar kilnBOT
raw star
Thank for the help
cedar kilnBOT
Available help channel!
lime citrus
Why is this answer wrong?
cedar kilnBOT
Why is this answer wrong?
void sand
I believe you have holes at x = 3 and x = 4
lime citrus
How do I find that?
carmine whale
How do I find that?
Is t(x) defined at x=3
sterile wharf
When combining functions (+, -, *, /) - You can never get rid of domain restrictions, only add them
carmine whale
When combining functions (+, -, *, /) - You can never get rid of domain restrict...
Isn't that a composite function ?
sterile wharf
I believe it's an operation of functions, slightly different
@lime citrus was that the correct answer?
If it's asking for composition it's something different
lime citrus
I believe it's an operation of functions, slightly different
Yes that was the correct answer, though it wasn't what my professor taught us in class so I was confused
sterile wharf
How did your professor explain it?
lime citrus
Actually looking at my notes, maybe that is what the was telling us I think I just confused, we only did one example in class
lime citrus
Yeah I wish we did more examples
I think we're going to cover it more in depth next unit, he just wanted to touch on it in case its on our exam for Thursday
Thanks for the help
lime citrus
Sure
Anything helps lol
I took alegebra 10 years ago so it's been hard to remember things
sterile wharf
I feel that
I skipped math for 3 years at the end of high school and restarting in college was a pain
Can I close this ticket?
lime citrus
yes
sterile wharf
.close
unreal bolt
cedar kilnBOT
unreal bolt
i dont even know where to start with this problem
balmy zenith
a percent is part/total
so the first step would be to find the total amount of money spent
unreal bolt
so add all the values together?
unreal bolt
i got 425000
balmy zenith
how much was spent on appliance department?
unreal bolt
10000
balmy zenith
so what percent was spent on applicance department?
unreal bolt
2.35%
balmy zenith
exactly
unreal bolt
OHHHHHHHH
balmy zenith
the percent is part/ total
step 1 calculate the total
then for each part, divide it by the total
unreal bolt
bro tysm
balmy zenith
you got this
unreal bolt
.close
crimson sedge
cedar kilnBOT
crimson sedge
How would I solve #22
unique thunder
what's a six letter word and it is a type of a real vector space ? <@&286206848099549185>
nova snow
what's a six letter word and it is a type of a real vector space ? <@&2862068480...
!occupied
cedar kilnBOT
what's a six letter word and it is a type of a real vector space ? <@&2862068480...
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).
unique thunder
this a password for a zoom meeting , I did not find anything
dire thorn
How would I solve #22
Trust the note. Do it component by component
unique thunder
ow sorry
crimson sedge
Trust the note. Do it component by component
Do I set x or y equal to 0
dire thorn
Do I set x or y equal to 0
Neither. Try answering this. If you multiply an imaginary number by a real number is it possible to get a real number?
cedar kilnBOT
@crimson sedge Has your question been resolved?
crimson sedge
Neither. Try answering this. If you multiply an imaginary number by a real numbe...
No
dire thorn
No
Exactly, same thing applies for addition/subtraction. That means changing the value of y will not affect the real part of the complex number on either side. It also means changing the value of x will not affect the imaginary part of the complex number on either side. This means we can set the real parts equal to each other, and the imaginary parts equal to each other and from there its easy to find x and y
7x=14 and -2yi=6i
dire thorn
crimson sedge
https://tenor.com/view/amongus-gif-20694761
Me when I realize what I did wrong
.closr
.close
somber snow
how do i fill the zeros and the multiplicity
cedar kilnBOT
how do i fill the zeros and the multiplicity
upper abyss
Why did you take the negatives of all the zeros
Multiplicity is what the zero "looks like". x = -4 is "like a parabola" so it has multiplicity 2.
cedar kilnBOT
@somber snow Has your question been resolved?
slate thistle
How should I prove this proof using the laws of logic
Only laws we learned: Detachment(Modus Pollens), Syllogism, Simplifcation, Contrapositive, Disjuinctive and Demorgans)
cedar kilnBOT
How should I prove this proof using the laws of logic
Only laws we learned: Det...
@slate thistle Has your question been resolved?
slate thistle
<@&286206848099549185>
cedar kilnBOT
@slate thistle Has your question been resolved?
obtuse sparrow
ive mana
obtuse sparrow
ive managed to reduce this integral to the following:
1/r^2 * 1/sqrt(1+r^2/x^2)
however, when I plugin my bounds, I get 0, not 2/R
r^2/x^2 reduces to just 0
so its just 1/r^2 - 1/r^2
What am I doing wrong here?
because r^2/x^2 goes to 0 when x = infinity
i see part of the issue. originally, it's ( x/r^2) * x/sqrt(x^2 + r^2)
and so when i try to do the simplification pulling out x from the square root i lose informatoin carried in the sign of x
but when i leave x in the numerator, I just get infinities in the numerator, and I'm having trouble reconciling that with the expected 2/r answer
<@&286206848099549185>
i believe ive figured it out, youve got 2 separate the integral into two pieces and sum them
.close
undone star
cedar kilnBOT
undone star
I’m not really sure how to do this question
opal basin
crimson sedge
cedar kilnBOT
crimson sedge
,rotate
wraith daggerBOT
crimson sedge
How do I do number 2?
hollow trail
a scale measures the normal force you exert on it, which by newton's third law is equal to the normal force it exerts on you. Set up Newton's second law (Fnet = ma), using the two forces (mg pulling down, given normal force), and solve for the acceleration
crimson sedge
So A is just 644/73?
hollow trail
you need to account for the force of gravity. Remember, newton's second law only applies to the net force.
crimson sedge
you need to account for the force of gravity. Remember, newton's second law only...
Could I get help with that?
I’m not sure what to add sorry
hollow trail
Let's start with a free body diagram of the forces at play here. The two that are relevant here are the force of gravity and the normal force
crimson sedge
Yes from the ground
hollow trail
The force of gravity always points down, and the normal force from the elevator floor points up since the floor is below us
crimson sedge
Ok
hollow trail
Based on that free body diagram, we can set up an equation for the net force
our net force should add up all of our forces, but forces pointing in opposite directions should have opposite signs (i.e., if a force pointing up is positive, then a force pointing down is negative).
crimson sedge
our net force should add up all of our forces, but forces pointing in opposite d...
Yo mb mb
I was falling asleep yo
Hm
Okay
What do I do with this info
hollow trail
you need to add up the forces to get the net force on your object
hollow trail
whenever you are on the ground, you are being pulled down by gravity. Considering that you are not falling into the center of the earth, the ground must be pushing you up. we call this a reaction force, specifically the normal force
because of newton's third law, this normal force is equal and opposite to the force you exert on the ground from gravity (a.k.a. weight)
hollow trail
depends on what you're talking about. weight is the force due to gravity. but when we measure weight, what we actually measure is the normal force you exert on a scale (which is equal and opposite to the normal force the scale exerts on you)
hollow trail
so we have two forces: one that is the force of gravity (mg, down) and one that is the normal force (apparent weight), up
so we set Fnet = sum of both forces, with upwards forces positive and downwards forces negative
this is important because of newton's second law Fnet = ma. so if we find the net force we can solve for acceleration
crimson sedge
so we set Fnet = sum of both forces, with upwards forces positive and downwards ...
Isn’t it just F_n - Fw then
hollow trail
in this case, yes
crimson sedge
What’s gravity in newtons
hollow trail
1 newton = 1 kg * 1 m/s². so mg is in newtons
crimson sedge
1 newton = 1 kg * 1 m/s². so mg is in newtons
So it’s just 644N?
Cause idk any other force besides gravity acting on it
hollow trail
no, that's the "apparent weight" a.k.a measured normal force
crimson sedge
Oh ok
crimson sedge
no, that's the "apparent weight" a.k.a measured normal force
F = 72.2(a) which I don’t know how to get
73 I mean*
hollow trail
We have two forces at play
- gravity = mg
- normal - given as "apparent weight = 644 N
crimson sedge
We have two forces at play
1) gravity = mg
2) normal - given as "apparent weight...
So just add 730 to normal?
I mean subtract
hollow trail
if your class gives g = 10, then yes
hollow trail
ok, that gives us the acceleration. which direction is that acceleration in?
cedar kilnBOT
@crimson sedge Has your question been resolved?
atomic steppe
cedar kilnBOT
atomic steppe
need help with 23
cedar kilnBOT
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
dire thorn
The equation of a line is y=mx+b. I believe you forgot to find b (your m is good)
cedar kilnBOT
@atomic steppe Has your question been resolved?
cedar kilnBOT
cedar kilnBOT
Available help channel!
onyx wing
Hello, so basically i have a sum of a transport fee (1260) which i have to spread to different goods (they come with the same transport) in the left yellow column there's the quantity in KG while in the right yellow the total. "Price" column is the price for each good, i wanted to spread it considering both quantity and price cause I don't want to put 0,86 cents on the 3,8€ good for example (sorry im dumb and thank you)
cedar kilnBOT
Hello, so basically i have a sum of a transport fee (1260) which i have to spre...
@onyx wing Has your question been resolved?
cedar kilnBOT
@onyx wing Has your question been resolved?
cedar kilnBOT
@onyx wing Has your question been resolved?
crimson sedge
ok, that gives us the acceleration. which direction is that acceleration in?
||ik this is someone else’s channel sorry but it’s down right?||
cedar kilnBOT
@onyx wing Has your question been resolved?
crimson sedge
Hello, so basically i have a sum of a transport fee (1260) which i have to spre...
Idk if you noticed but it’s pretty hard to see
cedar kilnBOT
@onyx wing Has your question been resolved?
cedar kilnBOT
@onyx wing Has your question been resolved?
onyx wing
<@&286206848099549185> sorry for the ping in advance
cedar kilnBOT
@onyx wing Has your question been resolved?
cedar kilnBOT
@onyx wing Has your question been resolved?
dire geode
Hello, so basically i have a sum of a transport fee (1260) which i have to spre...
this question isn't very well defined which is probably why you're not getting responses. can you be more precise what you mean by "spread" and what the goal is
onyx wing
I can try, i have six products which i want to add a transport fee to, they all come with the same transport and each time i pay 70€, so to make something more precise(hopefully) i chose a period of time and summed the quantities (kgs) for each product and i did 70€ x (times the transport came) = 1260€. In the Excel you can see i spread the transport fee to all the products but i only used quantity as a variable so i would like to involve the price of each product as well so I don't put the transport fee of 1€(for example) on both a product priced 30€ and one priced 2€ cause that would be kinda weird i think
amber ridge
I can try, i have six products which i want to add a transport fee to, they all ...
you can base it off of the total price of the items maybe
like, base it off of “goods total”
onyx wing
Hmm i tried but it's too high
amber ridge
Hmm i tried but it's too high
did you divide by 20787 at the end?
onyx wing
Hmm they're kinda skewed
The first three are kinda okay, the others are soo low
Like 0,00--
Fun thing is i did it last year on my own but i forgot how
Fml im growing dumber
I remember i used the two columns on the right and divided by 10 once
But yeah idk, numbers kinda weird
amber ridge
Hmm they're kinda skewed
well, what's the formula that you're using?
onyx wing
Well actually tried another and i think it should be good
Using the total and quantity column
crimson sedge
.open
amber ridge
@onyx wing Has your question been resolved?
onyx wing
Ur a weird bot
scarlet heron
Anyone help with this ?
cedar kilnBOT
Anyone help with this ?
tawdry atlas
Substitute the two terms in your right-hand expression with functions. So let $f(t) = t^5 + 3t$ and $g(t)=1-e^{-5t}$. Then you have $$ w(t) = f(t)\cdot g(t)$$ Now use the product rule to continue after you differentiate w with respect to t.
wraith daggerBOT
Ab
tawdry atlas
Differentiating w with respect to t, is akin to evaluating dw / dt.
scarlet heron
I’m a bit confused on how to differentiate this
floral arrow
Do you know how to differentiate each part?
tawdry atlas
I’m a bit confused on how to differentiate this
searching the product rule gives me this
you can apply the same logic where x is t instead.
and w is [f(t)g(t)]
(if you mean you don't know how to differentiate using the product rule. if you are having trouble differentiating each part, then it's an another thing. srry)
marsh pond
cedar kilnBOT
marsh pond
I followed the instructions here but didn't get it correct
a = (4,-4)
b = (3,-5)
cos(Θ)=[a•b]/[|a| |b|]
any ideas?
clear umbra
maybe try drawing it in a xy plane
lusty grotto
,calc acos((12+20)/(sqrt(4^2+4^2)*sqrt(3^2+5^2)))
wraith daggerBOT
Result:
0.24497866312686
Result:
0.23147736397018
,calc acos((-20+12-4)/(sqrt(5^2+3^2+2^2)*sqrt(4^2+4^2+2^2)))
wraith daggerBOT
Result:
1.9012189747064
cedar kilnBOT
@marsh pond Has your question been resolved?
stoic void
If you have two functions that are strictly increasing, is it safe to say they intersect at MOST one time?
prisma granite
no
stoic void
Can i get an example?
turbid mesa
They never intersect
prisma granite
yup
turbid mesa
You can also have infinitely many intesections
turbid mesa
Even when they are not the same functions
Now floor(x) is not strictly increasing, but one should be able to see that you can modify floor(x) such that the purple lines have some non zero slope and still intersect y=x, making it strictly increasing
turbid mesa
how will you make floor x tilted tho?
You don't make floor x tilted. You just observe from this figure that we can have a function which will be slanted like how we require
cedar kilnBOT
Available help channel!
wild grove
cedar kilnBOT
wild grove
Anyone can explain to me how we moved from the forth to the fifth step
royal finch
You can multiply the inside of an absolute value by -1 without changing the value
lyric narwhal
Hi, I was solving a question and I generated a functional equation, I was just wondering if it is solvable
lyric narwhal
The equation is $f^2(x)=1+xf(x+1)$
wraith daggerBOT
kheerii
lyric narwhal
f(x) only takes positive integer values
and it's output must also be positive (since it arises from a square root)
cedar kilnBOT
@lyric narwhal Has your question been resolved?
gritty viper
Is the ^2 iteration?
granite crystal
cedar kilnBOT
granite crystal
could i get some help with this continuity question please
im confused to as which part is the area
so A1U1=A2U2=A3U3
isnt u1 = 0 since its streamline is at the surface?
so surely q=0
peak minnow
cant u just use torcellis theorm to solve that?
to have h constant , the flowrate of the hole of container must be equal to the flowrate of the bottle
so calculate the flowrate of hole of container using torcellis theorm
peak minnow
yeah modified bernoullis
granite crystal
yea they are
should be
by the way for bernoulli's equation
for the static pressure p1
is that the same pgh?
rgh
which has a reference point from the atmospheric pressure so up to downwards on the container
peak minnow
use torcelli's thoerm , its modified bernoulli's and its v = sqrt(2gh)
v is the flow rate
g is gravity
h is height above the hole
granite crystal
yh im looking at it rn on wikipedia
peak minnow
and ik why they have given diameters , its so that u use
A1V1 = A2V2 = constant
but flowrate would be equal so its ok
granite crystal
yh
but im asking for bernoulli's equation
p1+rv^2/2+rgz = constant
is the p1
equal to rgh where h is the reference point as the atmospheric pressure
so in this case h would be from top to bototm
peak minnow
why use bernoulli's?
peak minnow
oh ok
granite crystal
for bernoulli's equation
p1 - static pressure
is that equivalent to rgh
where h has a reference point of atmospheric pressure
peak minnow
r is rho?
granite crystal
yea
peak minnow
yeah thats valid
peak minnow
np
granite crystal
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floral badger
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floral badger
Greetings, how do I prove what's written in the picture?
Do I use the determinant formula or is there another way?
dusty hazel
You'd have to evaluate the determinant eventually.
Though you can make the determinant easier.
By performing a few row operations and such.
floral badger
How?
dusty hazel
But ultimately, it's the determinant.
crimson sedge
yea u can erase a bunch of those 1's
floral badger
Ah fair enough
crimson sedge
then u can do leibniz expansion
floral badger
Still don't know leibniz unfortunately
But I'll try the row operations and then use the determinant
Thanks a lot for the advice though!
crimson sedge
oh sorry i meant laplace expansion
torn talon
Hello i need a help in french please
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Hello i need a help in french please
torn talon
Ahahaha t’es à l’affût
torn talon
dawn junco
si t'as check
dawn junco
le gars de la rochelle, maître maître nageur
dawn junco
oui c'est pas mal dense
torn talon
En gros tu vois ce que j’ai envoyé
J’ai fait la question 1
J’ai dit qu’il n’était pas vide
Qu’il était stable par addition et multiplication
Du Coup jen ai conclut que c’est un sev
Voilà je te montre tous ça
Mais à la question 2 je bloque je vois pas comment m’y prendre je voulais exprimer des trucs selon t mais vu que c’est pas égal à 0 bah j’arrive pas
dawn junco
on te dit rien sur x, y, z, t, à part que c'est des nombres
dawn junco
en vrai ta preuve est plutot ok
t'enlèves les x=y=z=t=0, que t'as mis un peu partout et c'est bon plus ou moins
torn talon
Mais tu vois quand j’ai dit que tout est égal à 0 si je dit ça c’est faux ?
dawn junco
bha oui
torn talon
Ah ok
dawn junco
il y a rien qui dit que x=y=z=t=0 dans G
torn talon
Commet on saura que c’est vide alors
torn talon
Oui voilà
dawn junco
pour montrer que le vecteur 0 est dedans, oui tu mentionnes que pour x=y=z=t=0 t'obtiens bien le vecteur 0
pour le reste non
dawn junco
t'as montré que 0 était dedans ok
la seule condition qui importe pour qu'un vecteur soit dans G c'est qu'il soit de la forme (x+z, x+t, y+t, y+z)
c'est tout
torn talon
Ah mais c’était plus simple alors
Je me suis casser la tête à faire des op bizarre la orgh
Si pas possible
dawn junco
et pour la multiplication par un scalaire c'est pareil
tu t'arrêtes avant d'introduire des op bizarre
et t'as déjà montré que si f est dans G, alors lambda*f est dans G
gagné
torn talon
Je le fait et tu le corrige encore ?
dawn junco
oui
dawn junco
mieux mais j'ai du mal à comprendre la fin encore
pour l'addition on voit mieux où tu veux en venir, parce que tu regroupes les x, y, z, t des deux vecteurs ensemble
torn talon
Pourquoi
dawn junco
donc on imagine bien que le "x" de f+g c'est x1+x2
que le "y" de f+g c'est y1+y2
etc...
dawn junco
ça pourrait être mieux affiché mais on voit bien l'idée déjà
dawn junco
J’aurai du utiliser la mm méthode pour la multiplication c’est ça ?
ouais
dawn junco
si tu veux faire ça clean
torn talon
Fin par x1 y1 z1 et t1
dawn junco
tu peux définir de nouvelles variables X = x1+x2, Y=y1+y2, Z=z1+z2, T=t1+t2
et dans ce cas-là f+g = (X+Z, X+T, Y+Z, Y+T)
là c'est vraiment apparent que f+g a la forme souhaités
dawn junco
et dans ce cas-là f+g = (X+Z, X+T, Y+Z, Y+T)
là faut vraiment avoir perdu deux yeux pour pas voir que ça marche
torn talon
Attend je vais d’abord faire l’addition à la perfection àlors avant de faire la multiplication
dawn junco
et tu peux faire un truc similaire pour la multiplication
dawn junco
ça change pas, c'est toujours des vecteurs de G
dawn junco
le début est très bien, introduire f et g, puis regarder f+g il y a aucun souci
torn talon
Ah c’est après genre on dit
dawn junco
ma suggestion c'est juste de rendre la conclusion plus lisible, plus percutante
dawn junco
oui voilà
torn talon
Enfinn
dawn junco
là on voit très explicitement que f+g est dans G
torn talon
Mtn on attaque la multiplication
dawn junco
pour des preuves de routine comme ça (montrer que tralala est un s.e.v.), faut vraiment être carré
donc si tu peux simplifier la vie de la personne qui lit ton truc, et qu'elle ait pas de détails de preuve à remplir elle-même, c'est tout à ton avantage
torn talon
Okay merci chef
Là le prof s’il voit pas ce que je veux faire je lui crève les yeux
dawn junco
si tu veux vraiment rester dans l'esprit de la preuve pour l'addition
faudrait plutôt poser X = lambda*x1, Y = lambda*y1, ...
comme ça t'as littéralement lambda*f = (X+Z, X+T, ...)
torn talon
dawn junco
yep
torn talon
La question 2 du coup explique moi comment faire pcq vu que c’est pas égal à 0 à chaque fois j’arrive pas à exprimer des choses en fonctions de qlq chose mmdrr
dawn junco
bha l'idée c'est qu'il faut que tu trouves un ensemble de vecteurs {v1, ..., vk} qui génère G, et qui soit libre/linéairement indépendant
c'est ça les deux conditions pour être une base d'un e.v.
que tu puisses générer G, ça veut dire que n'importe quel vecteur g de G peut être écrit comme une combinaison linéaire g = a1*v1 + a2*v2 +... + ak*vk de v1, ..., vk
et être libre/linéairement indépendant ça veut dire qu'il y a une unique manière d'écrire g comme combinaison linéaire de v1, ..., vk
ça c'est le résumé en 2 minutes, pour avoir une idée rapide
mais je te conseille de check les vidéos du gars de la rochelle sur le sujet
il y aura plus d'exemples et ça sera mieux expliqué
@torn talon
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torn talon
Dsl ma tablette a buger
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dawn junco
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jagged wave
Is the same AxA^-1 and (A^-1)xA being A a matrix of order n???
jagged wave
I know that a matrix might not be conmutable, but does it still happens even when one matrix is the inverse of the other one?
digital cliff
its the same here yeah, they both give I_n
dusty hazel
Inverse of a Matrix commutes that Matrix.
Because yeah, it gives identity Matrix of that order as the product.
lapis laurel
a crab wants to build a house with an area of 490m^2. The house has to have a distance of 5 meters from to edges of the property except from the front of the house where the distance is 9 meters. What is the smallest area property the crab can build his house on
muted timber
!show
cedar kilnBOT
Show your work, and if possible, explain where you are stuck.
lapis laurel
ok well ive come to the conclusion because the house is built in the shape of a rectangle it will have the most area when its square
im stuck because im unable to form equations from the given information
muted timber
did you try to draw it?
lapis laurel
something like thos
muted timber
good
now, the area of your house is xy=490 (im gonna ommit the units, assume everything in m or m^2 as appropriate)
so y=490/x
lapis laurel
yes
muted timber
but you dont care about the area of the house, you care about the area of the property
lapis laurel
yes thats also true
muted timber
the area of the property is (x+10) (y+14)
Replace y for the value we got before. Simplify as much as possible. Gimme the equation with only x.
muted timber
keep going
lapis laurel
muted timber
okay so that's the area of your property, according to whatever x you choose
now they ask for the minimum area
lapis laurel
now i assume i am supposed to differentiate it
muted timber
you know that the minimum area is obtained at the point where the derivative is 0
so derive that, and solve for A'(x) = 0
and you should get a crappy number with radicand
lapis laurel
what is a radicand?
astral arrow
lapis laurel
i got something like this for the x
so the width of the house is approximately 6 meters
gray oyster
Can someone help me explain how do we find the correct answer? I’m not sure about this one
gray oyster
I just guessed cuz there were only few seconds
dull oxide
Consider $\lim_{x\rightarrow a} g(x)=0$
wraith daggerBOT
SWR
gray oyster
Hm?
gray oyster
Can you divide by 0?
Why divide by 0?
dull oxide
dull oxide
could be discontinuous
gray oyster
Yeah ik, we have to choose the ones that could be discontinuing
But how we find which one by dividing by 0?
dull oxide
Yeah ik, we have to choose the ones that could be discontinuing
consider f(x)=1 and g(x)=0
jaunty mural
Yeah ik, we have to choose the ones that could be discontinuing
You don't get to choose.
The question is phrased very specifically
gray oyster
Oh
So if the answer was 0, is it discontinued?
Sorry if I didn’t understand yet
Like we have in the question:
1+0=1
1-0=1
1/0= undefined
1*0=0
I replaced the f(x) by 1 and g(x) by 0
So what’s next?
What is the answer to the question, and how to explain?
gray oyster
Can someone help me explain how do we find the correct answer? I’m not sure abou...
<@&286206848099549185>
native egret
Mommy
dire geode
I replaced the f(x) by 1 and g(x) by 0
Pick a different function for g
1/0 is undefined
Oh I guess that's enough
gray oyster
1/0 is undefined
So if an answer is undefined, does that mean that it is discontinued?
I’m asking to just keep in mind @dire geode
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grizzled jetty
Hey
dapper cairn
did u try?
grizzled jetty
I did
dapper cairn
show me
dapper cairn
why i wrote i^20
dapper cairn
write 20
dapper cairn
u know why right?
grizzled jetty
Yes thank you and now I’ll use the formulas that we learned in grade 9
dapper cairn
Yes thank you and now I’ll use the formulas that we learned in grade 9
nop
grizzled jetty
Nope?
dapper cairn
no problem
grizzled jetty
Oh wait
It’s actually simple
We form groups of 4
That will evaluate to 0
So it’s 0
Isn’t it?
mild narwhal
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mild narwhal
i missed one h
digital cliff
ah i see
stoic garnet
so I know B and C are the answers but I dont know how to find them with the known angles
brisk apex
try and find "g" first
you can do this by noticing that there is a "180" degree angle that already has the values "61" and "54"
using this you can finding the missing angle, you can then use the corresponding angle theorem to find "g"
sorry if I'm a bit unclear
not rly the best at explaining
stoic garnet
alright thank you!!
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tight cove
Why is it that when rationalizing a denominator with one square root only one of them is affected by multiplication but when it’s more than just a square root it affects all the numbers
dull oxide
wdym
tight cove
So in the image on the right
When rationalizing the denominator say multiplying it by 4 root 2, the 3 and the root 3 are not affected, only the two is
But on the image on the left everything is affected
Why
rustic siren
wdym affected
tight cove
It doesn’t get multiplied by root 2
rustic siren
u multiply both the denom and the nom in both case, so everything is affected by it
it is affected in the first case too, thats where u get the 2 in the denom
tight cove
But the 3 and root 3 don’t get changed
rustic siren
ofc
(3 * 5 * 7 * 9) * 2 is not (6 * 10 * 14 * 18) only one "part" gets doubled
in our case its the 2^(3/4) part that gets multiplied
were you referring to this?
rustic siren
can you circle it?
tight cove
rustic siren
the previous thing was the (associativity)
tight cove
Thanks
rustic siren
you will learn these properties name in algebra, if you have not seen them already
elfin bluff
can someone please help me figure this out...
cedar kilnBOT
can someone please help me figure this out...
elfin bluff
I do not even know where to begin
I'm supposed to solve it using excel
If you can help me figure out the first one, I can do the rest myself
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crimson sedge
If you can help me figure out the first one, I can do the rest myself
ok
so each confidence interval should be centered around 0.44
do you understand that?
elfin bluff
yea I guess
crimson sedge
wdym I guess
say someone asks you to give me a guess about how many ounces of water you drink per day
the inital guestimate would be the point estimate
elfin bluff
Ohhh so 0.44 is the middle right?
crimson sedge
now if I said
give me a (balanced) interval estimate
that you are 99% confident
would capture the true amount of water you drink per day
crimson sedge
the inital guestimate would be the point estimate
it would contain this inital estimate, correct?
forget the problem for a second
@elfin bluff
elfin bluff
that you are 99% confident
Ohhh yea I understand now
crimson sedge
ok
so now we get to more formally defining what a confidecen interval is
confidence interval $=$ point estimate $\pm$ possible error
wraith daggerBOT
! matthewzz
crimson sedge
the higher % the confidence interval is
the greater the "possible error is"
since you are going to be 99% CONFIDENT that the true parameter is in the interval
if we specifically assume that the parameter is normally distributed and we know the standard deviation we can define it even more formally
confidence interval $=$ point estimate $\pm$ standard deviation * z score corrosponding to your X% confidence interval
wraith daggerBOT
! matthewzz
crimson sedge
in variable terms:
$X% CI = \mu \pm \sigma * z_{(100-X)}$
wraith daggerBOT
! matthewzz
crimson sedge
can someone please help me figure this out...
so looking at your initial problem, the 99% CI should be the widest, the 95% should be the second widest, and the 90% should be the third widest (or the shortest)
elfin bluff
so looking at your initial problem, the 99% CI should be the widest, the 95% sho...
wait...so I wasn't supposed to do any actual math?
crimson sedge
wait...so I wasn't supposed to do any actual math?
no, you dont need to if you know the concept of CI the best
the higher % the confidence interval is
the greater the "possible error" is, which means your confidence interval will be larger
intuitively it makes sense,
since you are going to be 99% CONFIDENT that the true parameter is in the interval, the intervala better be pretty wide, to make sure youll capture the true value
elfin bluff
I notice now....I didn't understand the concept at first that's why I was confused
thanks bro!
crimson sedge
thanks bro!
Thanks, please .close when done
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feral basalt
Help please?
cedar kilnBOT
Help please?
feral basalt
Idk how to do problem 2
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proven condor
how do i solve this problem?
proven condor
<@&286206848099549185>
pastel vault
how do i solve this problem?
can you find the normal vector of the plane?
after that the line has direction vector (2, -2, 1) as x = 2t + 1 etc.
so you just need to find the angle between those vectors and subtract 90 degrees
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