#help-0
1 messages · Page 863 of 1
We know that 360 degrees is how many angles it takes to go around a full circle (not very exciting)
And 180 is the angle of our sector for this picture.
ok
Right?
right
Well.... Here, 360 is the full revolution, and 90 is the angle of our sector.
ok
Agreed?
agreed
Okay, so already with a couple of examples, we see the number of sectors it takes to fill up the circle is 360/theta
theta is the arc length of the sector?
It is the angle
ohh ok
Of the sector taken in consideration
A_s stands for area of the sector
ok
Well, now we can just do some nice algebra
what abt A_c
A_c is area of the circle
Usually if I don't say what my subscripts are, they are exactly what youd expect them to be :p
time to note down stuff
And bingo!
Nice handwriting
which channel do i go to ask about something relating to statistics
i am doing area of circle luture in class
This is a more simple explanation without going into depths
anyone want to join
Lol, is that sarcasm
Gonna go with #probability-statistics
no i am not lying
lemme note it down first
somehow missed that when i was looking through channel names
Thanks then
So we come to our conclusion. The area of the sector is the area of the circle times theta/360
Don't note anything first, try to understand
If you still haven't understood I can try to explain in dms
Same question?
no mabye a diffrent one
But the question itself isn't clear
No, it was. What is the area of a sector.
Are asking what is the formula, or why the formula, or an in depth dive into it
You*
Probably the first, but I am not just gonna give a formula. That is not very helpful.
area of the sector = A_c x Central Angle/360?
It is not
Correct
Where A_c is the area of the circle
Yay I understand now ty
please come the the voice chat it will be super easy for me to under stand
Fantastic :D
But sometimes working backwards from the formula to why it works might help some people understand
pls
Circle stuff is very confusing
I'm here
Everything has the potential to be very confusing at first. It gets easier the more you work with it.
How about a more simple explanation
Pi is very confusing for younger people
A sector is basically a fraction of the circle
Pi is just a number
But it is a very specific number that shows up all the time when dealing with circles (and other things)
still confusing
yes i think
It is a fraction of the circle
So 1/4 of a circle will have 1/4 of the area right?
is ther anything wrong with my work? (using change of base formula)
Lol how old are you?
sector = pir^2 Central Angle/360
must i say
No, you do not have to say
You dont
ok
I also encourage you not to
i wont
ok
So like in dackids example
Sometimes, the sectors have angles of 90 degrees right?
yes
Those sectors are 1/4 of the circle
not all sectors are 90/360
Sector angles with angles 180 degrees are 1/2
Yes I am approaching the point
But like you said, not all angles are 90 or 180
So how do you figure out how much of a part the sector is?
What if the angle is 30°?
Just divide the angle ( which is also called theta) by 360
true
I am assuming you are 14-15 because that's also around my age
no i am 13
then it would be pi r2 x 30/360
is that good
I'll just say 1 thing
or what
im not 15
ok
So don't let age discourage you
where did bob ros go
I'm here
lol
yay
Continuing with the explanation
For finding area of any sector
All you have to do is take the angle of the sector, divide by 360
okay
That gives what fraction of the circle the sector is
ok
and then you find the angle
Done
Cosine?
Trigonometry?
yea
The basic definition is pretty easy. One sec
Dackid, was there any loopholes in my explanation?
Super quick. Let theta be our angle. Then cos(theta) is the length of the side next to the angle divided by the hypotenuse.
[\cos(\theta)=\frac{adjacent}{hypotenuse}.]
dackid
In this case, the side next to our angle has length a, so the adjacent=a. Note, adjacent literally means next to.
The hypotenuse is the longest side of the triangle, which is c.
So using our lovely formula here, cos(theta)=a/c
Note, this formula is a definition. There is nothing to derive.
No. A_c just denotes the area of the circle. Moreover, I gave it that notation. That's just what I chose to call it. It's just a convenient name.
A_c DOES NOT universally mean the area of the circle. I just wanted A_c to represent that for this scenario. That is all
Hi, I had a question on radical expressions in algebra, is there a simpler way to simplify large index numbers and large radicand
Oh sure. Well, we need to factor 405.
405=20*21=4x5x7x3
Since there are no repeating factors, this is as simplified as it gets
Oh wait, hold up
4=2×2
How did they get the term a to become 6?
this is correct right? change of base formula
Yes, but it isn't very useful.
I think I understand, thank you
In fact, that is just the same thing.
Log(10) is one, so nothing interesting has been said there
Hold on, I made a small error.
i'm being asked to proof this. not too sure about where to start
if you must, please take your time
[\sqrt{405}=\sqrt{5*81}=\sqrt{81}\sqrt{5}=9\sqrt{5}]
dackid
That's better.
Well, what is ln(e)?
is it possible to simplify 9 radical 5 further, specifically 9?
Well, 9 isnt even in a square root. Cant do much to that
And sqrt(5) is an irrational number. That is as simplified as it gets
Area of the sector = r^2piCentral Angle/360?
I don't think geometry changed its rules in the past 30 minutes :p
Oh, because I thought you could go beyond and go 3 and 3
How did they get the term a to become 6?
Well, that would be if it was still in a square root. But it is not anymore
You betcha
After you expand it out, the coefficients for each power have to match
For x^2, you'll end up with 3 being the coefficient for x^2 on the left and -3+a being the coefficient for x^2 on the right.
Set them equal to each other. 3=-3+a, so a=6
how is it -3+a?
Expand the right side out and see for yourself
x^3+ax^2+8x-3x^2-3ax-24
Yep. You have ax^2-3x^2. By combining like terms, this is just (a-3)x^2
Closer
can you please explain me what is Log
log is a tree
no in math
Well, part of a tree
oh ok
k
Hmm, do you know what exponents are?
what do you mean by that
what is the average age for a human being to learn bout circle stuff
ok
i think it depend what country you are in too and school
like for me i go to James Ruse
Well, you are learning some pretty basic things rn. In 10th grade, you learn a LOT more about circles.
But I will admit, I forgot almost everything we learned on that stuff
i mean it depened on your school
Geometry is not something I've put a lot of focus on
why
Sorry, I have a bit more questions on radical functions, how exactly does division with radicals work
bc im too used to multiplication
Other math topics hold my interest. Moreover, they are also the classes I am in right now. Geometry took a bit of a back seat
cyretsu, do you know what exponents are?
same
Yes
so can i do calculus
Okay, let me let you in on a little secret. [\sqrt{x}=\left(x\right)^{\frac{1}{2}}.]
dackid
So if you know how exponents behave, you know how radicals behave
Sure! It's likely you don't have the fundamentals yet, so learn them if you want to do calculus early!
Not yet. But you certainly habe the ability to understand it
Algebra is incredibly fundamental to working with more advanced mathematics.
I'm in college. I am taking topology and abstract algebra rn.
what college
I am not going to disclose that info.
You're fine. Location/age are things that probably should not be discussed in a server with over 20,000 people in it
There's probably a difference, but I sure as heck dont notice it :p
How many 3 digit even numbers can be made with 0,1,2,3,4 and 5, without repetitions of numbers? Can someone help me with this
Universities offer post-undergrad studies, while colleges just offer 4 year programs
Ah, good to know. I am at a university then
52
52
Is a number. I can agree
How’d you do it?
okay give me a minute to write it in discord
Kk
Yeah that’s 2 digits lol
It does make a big difference
Okay. I got a feeling their approach didnt take this into consideration.
Getting mixed signals here :p
lol
i am trying
Ight send working when u got it
k
whats a nCk
same
n choose k. How many combinations of k items can you make from n items
It’s combinations
x
Yeah
Yep, precisely what you need
all i do is, start from 1 number by 1 number
Okay here is the deal. There are 3 possible digits the last digit could be, 0,2, or 4
Ye
okay
Great. Now the middle digit can be any of the 5 remaining digits
Im already confused
Okay cool. Now, there are two possibilities: either 0 has been used or it hasn't
So wouldn’t it be 5! x 4! times 3?
If 0 hasn't been used, then the choice of the last digit is free, so any of the four remaining works
No
Wait nvm
However, if 0 has not been chosen, then you have exactly 3 digits left to choose from (you can't choose 0)
k
Hey
content://com.android.chrome.FileProvider/images/screenshot/1634621873389963715025094858063.jpg
.
How do I solve these 2 questions?
@coral pagoda got an answer for my question yet?
ohh yea
We have, digits 0,1,2,3,4 and 5
Even numbers-
(i) when 0 is at unit place, then
There are 5 ways to fill 10's place and 4 ways to fill 100's place
So, no. of ways =4×5=20
(ii) when 0 is not at unit place, then
There are 2 ways to fill unit's place, 5 ways to fill 10's place and 4 ways to fill 100's place
So, no. of ways =2×5×4=40
2 or 4
∴ total number of even numbers 40+20=60
the answer
Pls help me too
Okay cool. If 0 is chosen first, you have 5*4 ways of arranging it.
but ask dackid he is the smartest
Hey
Pls help
In solving these questions
Bro wait your turn lol
If 0 is chosen 2nd, you have 412 ways of choosing it
If 0 is not chosen at all, you have 3x5x2 ways of expressing them.
do you think my ans is correct
Sir
Oh
My turn?
Alright yeah your turn
TeXit Is So Useful
Wait, I mathed wrong. You may be in luck
My mind keeps forgetting there are 6 digits instead of 5
what do you think
Everything but the first part was right. This should give you the correct result now
You cannot have 0 to be in the hundreds place
I am going to go to bed. Please ask in an unoccupied channel
.
I hate to be a buzzkill, but they cant help you with this one.
Bruh
Not yet anyways
mabye ask other chats
There are 9 other channels to ask in
yea man
All are dead right now
ask other server
That's a good thing
Adios
Bruh
what da
how do i use implicit differntiatiation to do 3xy^2+y^3=8
Isn't this literally the same type of problem as the first most basic implicit differentiation example you learn?
yea
That pink has troubles starting it (I presume) raises some questions
?
help me then
bro why am i moving the 8
can someone help me create a general equation for nth derivative of this equation
yea ik
but just to make it ncie
step by step
Then u differintiate it
like 3*2xy^2-1
@alpine sable
moriaty at first glance would you know the formula for the nth derivative in the picture shown above?
what
@eternal osprey If your other browser tabs are for this problem, can I just say, watch your parentheses
@eternal osprey use quotient rule
do i not use product rule
why product rule?
I know how to derive it... but finding nth derivative is different. So far I have concluded that the top term must be -n-3
for 3xy^2
use additionand substraction rule
like 3y^2 is count as one
for using product rule uneed like 2 term
for example
(3x+2)*sqrt4x-1
ehh do u get it @alpine sable ?
ican do 3x and y^2 for product rule
ohhh sure just try it but
if u wanna crosscheck with my answer
my answer is
-y/2x+y
and you're trying to find... which values of x satisfy the equation?
i got x=-7 and x=1
what I would do is split the equation into two parts
do u need step by step?
Photo math says that but doesn't makes sence
what
This is an example
Ohhh
Of the question
for me like
The different is in that question the "C" is already 0
ahahahaha yeaa
yepp anytime!
hi i'm not sure on how to tackle this problem
i tried taking the derivative of the original equation and setting it equal to the tangent line equation
but i don't think that's what i'm supposed to do, right?
@opaque totem wtf am I doing wrong
yepp
?
What
How do i find the arc length of the sector?
apply the formula for arc length
erm whats the formuka
and/or consider the fraction of the arc and a full circle
am stupid to know man
i feel like its wrong but idk
Are you asking for all x in general?
yes
Nope. That isn't correct
wd4q5dy
And also, square root is not that well defined in complex numbers. So you get two forms
wd4q5dy
what
Like, you could say $\sqrt{i}=\pm\frac{i+1}{\sqrt{2}}$
Euclid31415
okok
$\sqrt{xi}=±(\sqrt{\frac{x}{2}}+\sqrt{\frac{x}{2}}i)$
if you want it to be more clear
wd4q5dy
Or you could consider a "principal" square root
This does look ok
I thought you assumed x some positive real
i didnt assume anything
i just wrote it on paper
maybe it only works for positive reals
let me verify
If x=i then you have to consider square roots of i again in this format
find the m which is the derivative, so like x^2/81 become 2x/81
look
look?
What
check ur answer again maybe miscal or u forget smtg
Ok
I can't seem to reason how the associativity law works in matrix multiplication
in which A(BC) = (AB)C
ahahahah borutoeyepower
jogan
- Determine the quotient
a. 2x2 – x – 10 by 2x – 5
b. 4x2 + 16x + 15 by (2x + 5)
- Determine the result of the power of the algebraic form:
a. (3x + 2y)3 =
b. (3y2 – 2y)4 =
pls help
if the channel is free quick question how do we find for (c)
no
rip
@opaque totem sorry for ping but u know how to solve (c)?
sorry broo idk
@sharp barn didn’t I help you with this?
u help q6
Yeah we already did it?
v=u+at
Do you know that formula?
i know a= v-u/t
what we finding is t right?
so the acceleration is 2.5
You’ll use the acceleration from part b
v is after? u is initial?
so its 14 s?
Yes
then for d how does the graph look like?
like this?
but it say sketch right?
and there is nothing to plot
You can plot 35,14
There can be a change in direction which means there is acceleration
thats the answer for f?
@keen mulch sorry for ping but how do we explain for (d)?
it has 3 marks
you will have to translate for those of us who don't speak Romanian.
Hi
I know how to do A-B
In a set
But how to do |A-B|?
Which is inside mod
Is it just the numbers of elements in the set?
yes
cardinality is the term
what is polynomial function’s formula??
A polynomial function is a function that involves only non-negative integer powers or only positive integer exponents of a variable in an equation like the quadratic equation, cubic equation, etc. For example, 2x+5 is a polynomial that has exponent equal to 1.
$p(x)=a_{n}x^{n}+a_{n-1}x^{n-1}+...+a_{2}x^2+a_{1}x+a_{0}, n\in \mathbb{N}_0$
.itsjustnai
channel busy?
nope
Crumple zones add time to a crash by absorbing energy, seatbelts exert a force back to the person which prevents the momentum from sending the person flying into the steering wheel, etc. Something along those lines should suffice @sharp barn
how is the answer 81 and not something else?
@clever hare @novel loom one of you will have to move to another channel.
I don't think the answer is 81
You have to determine the condition of existence. Once you have calculated that, use the properties of powers and bring the term with the unknown to the left side. Add the left terms, divide both terms, and set the base equal to 0, check the solution and there you have the answer : )
this.....looks and sounds unnecessarily confusing, nerno
How does it look confusing ?
I just gave him all the steps to calculate it
"condition of existence" for a problem that involves nothing more than simple application of exponent laws? please
there is no left or right side either
There is tho
Wait
I'm about to grab a piece of paper, one sec
wait are you french
No I'm not french
Hi
How to prove the above is true?
2.16
We have to just write truth tables for all abcd and e?
no...
you first determine whether P is true, then determine whether Q is true, then find the truth value of each statement from a to e
@vale wigeon almost done btw
@alpine sable please help. I'm crying
so you know the values of P and Q... do you know how to evaluate P or Q?
No, all I know is p is false and q is true
so you don't know how to do Boolean algebra?
Wait, I'm looking at it
Thx, I came to the conclusion that the sequence is convergent
\begin{tabular}{c|cc}
or & T & F \
\hline
T & T & T \
F & T & F
\end{tabular}
@vale wigeon the truth tables right?
Ann
I know
please tell me this isn't foreign to you
so why can't you apply these tables here?
nerno you definitely misunderstood the problem
so @vale wigeon you are telling to apply all those to the tables right?
Okay
Thnx
What have I misunderstood? So wait, r you trying to say I did all this for nothing
tysm can you sight me atleast 1 geometric sequence example
do i have to add +C? this is a physics problem btw
in our previous modules, they do not add +C so im confused :/
help pls
ohhh i seeeee. that helped thanks
hi, i need help . determine f′(4) if
f(x)=x√x
I prefer to solve it by assuming p = √x.
f(p) = p²p = p³.
dErIvAtIvE of this should be easier.
Other ways include x√x = x(x^(1/2)) = x^(3/2) and then apply power rule.
Or, use product rule.
why is this the answer
this is my work
im getting a diff answer
can anyone identify wat im doing wrong
What does
P: A ç B
Q: |A-B| = 6
mean?
Then the last step is definitely sus.
yeah thats what i was thinking
idk how else to combine them tho
What do they mean by "sup" here?
supremum
hi everyone im 11 and when i need help i can ask here right?
yap
I've asked this previously, made some progress, but I still need help because I don't think I fully understand this question. How do I prove that f is differentiable in 0?
I tried using this, but it only tells me that f diverges and is not differentiable? Did I write it wrongly?
i could be wrong, but i think you just need to demonstrate that the limit of the x != 0 case is -1/2
That might work, how do I prove it though? I thought you had to do something with the first expression (ln(cosx)/x^2)
at x = 0, the x != 0 case is 0/0, so i assume you'd apply l'Hopital's rule
i dont think you should use this to prove it exists, because it becomes much more rigorous. You just have to prove that f'(x) is continuous at x=0
usually you use first principle to prove the continuity because its faster, you dont have to find the derivative and then do the limits to check the continuity at some random points
also, you applied the first principle wrong
you are proving that it exists at 0, so your x should also be approaching 0 from both sides
which means you use the other branch of the function and not the upper branch (ln(cos(...))/x^2) thing)
channel might be busy, you should move, unless madmobius doesnt have any other questions
What is locus ?
It's long division
I known
but with letters instead of numbers
know*
MAN
It's a shitty implementation of polynomial division
It's basically an extension of numeric long division
A better way of dividing polynomials is synthetic division
Which is way way faster and requires less brain cells
The sum of the area of two squares is 26cm² , which also has the difference of their sides 14cm , calculate the area of the values of these squares approximately
have you two... tried anything?
ok
how i make it a equation
Well there's the method of elimination for starters
google it if you don't know what that means
(7x-1)(3x+4)
this was another question
ok i am sorry sir
Thank you
😂 👍
you can google second order linear diff. eq for starters
Is it linear?
I have no clue
Yes it is linear but that’s not the point of the question
This is not solvable using any techniques I learned so far, I don’t need the general solution, just one specific solution, there is meant to be something obvious which satisfies this but I have no idea how to find it
z=x?
lmfao
🤯
yeah that works
Well thanks bro
erm, how do i find the area of the sector
erm no
then do that jesus
ok
can someone check this
still dont understand
@edgy cipher 1. that's not a question 2. why would we do that
@near falcon what kind of sector do you mean
im not sure if i did this right
area of a sector, like a circle
this isnt a quiz bro ive done this many times this is a practice quiz that i take and i see how i did than i take the real test
ok
besides its not graded
im going to see all the answers tho
@near falcon so basically, a sector is like a slice of pizza right?
ye
Can someone explain me this/solve it with me in DM?
Function y= f(x) is given down.
Calculate f'(2) and f''(2)
How do you know how much pizza you're getting when you slice it?
yeah that's it basically
ok
Erm if someone can i can pay you for it too.
is this an exam
Such a dumbass tagging mods i can pay for private math lectures
Regular thing in school
??
we got a cheater here don't we
You're not gonna pay someone to do work for you here
yeah we do
To teach me how to do it*
he's paying someone to teach
there is no need to offer money for that in this server, and in fact, offering money is against the rules
so please don't do that here
in a way all of us are willing to teach as long as it abides with all the rules
Alright im just beeing generous
yep
they mean the finite differences approximation
this is common in numeric methods
anyway, good luck
haha
The total area of this triangle is 39
How do i solve this
Its asking for the value of X
0.5 x (x-3) x (x+4) = 39
Good day
Simplify and solve for x
Just plug triangle area formula
dont give answers
does nothing to actually help
a question, do you know the formula for triangle area?
Probably
Oh sorry, I'm not much active here
No, 1/2 x height x bottom
“Base”
bottom?
the word you're looking for is base
you could also use (base * height)/2
thanks, im just telling the words that he/she understand it better
if he/she used the bottom word
so he'll understand better
well idrk the terminology in mathematics
he is foreign person i think
Bruh
you should know it
they'll appear in the questions
and you may not know what theyre talking about
They do appear but not in english
||In Chinese is 底|| , base is not necessarily bottom bruh
What if they mistake something for base just bc it’s at the bottom
@barren river where are you from?
no problem, can i disturb you in dm please
Very apparently im a chinese
ok.
Nah as long as u guys can understand what i mean its fine
Oh!!! , I love china
anyways how do i solve that
Well what is the base and what is the height
X+4 is the base
X-3 is the height
X+4(x-3)/2

Oh OK, there's no force. i just wanted to speak with you a bit and give you some proposal
make sure u write it like ((x+4)(x+3))/2
theyre all being divided by 2
u could also just do
have you learned how to solve equations?
1/2(x+4)(x-3) @barren river
yes
this is better
but that just confused me earlier
if u write it like this, its less confusing
OK, so you can solve it now using it
because its 1/2bh
so do i just
Expand
X(x-3)+4(x-3)
what
Expand first
The a^2-b^2 one?
there's no difference of squares, just expand the binomials then solve the quadratic
im having some confusion
Fuck i meant height x base /2
sorry I wish I could write in chinese
ok that is fine, but make sure u multiply height and base first
yea so look
wdym multiply
oh
yea i got it
x+4
X-3
yes
ok, now just put them in their spot
so if it is base x height / 2
how will u write this
so that u can solve it
uh
remember u know area is 39 right?
yea
perhaps make the 39 to the left side or something
Remember if u have a fraction like this
U want to get rid of it first
How can u get rid of the fraction
times it
eggdog
there
ok so multiply by what though
instead of times u can say multiply, they are the same thing
Ur right
Multiplying will get rid of the fraction
But what should you multiply by
2
Right so
$\frac{(x-4)(x-3)}{2}\cdot \frac{2}{1}= 39$
ok u dont have to write it out like this, i think u know
but u want to multiply it by 2 on both sides
what will it look like after u do that
x+4)(x-3) equal 78
maybe u can get the 78 to the left side and replace the original with 0 but idk
u have to do something called foil
except its not x+9 and x+1 right
And +4 (x-3)
no not like that
try to look at the diagram
or the picture I sent
how can u apply it to (x+4)(x-3)
unless they taught u different way idk
X(x) + 9(x) + x(1) + 9(1)?
yeah thats right but now multiply everything
right so like
because right now u have things in parantheses that can be multiplied lol
parantheses is this ()
X(x) +4 (x) +x(-3) + 4(-3)
uhh no
go back to this
this was right
so now what's x(x)
X2 +9x+x+9
yes
x2+10x+9
