#geometry-and-trigonometry
1 messages · Page 135 of 1
i might have missed up a term but i did the taylor series for sin(1) by hand
oh i did 1/8 instead of 3/8 oops
tiny error
Taylor series is genuinely gonna make me commit why-did-I-take-this-class-ide
😳
lol
rawr
real talk why dont we just take the modulus of the input for the taylor series for sine and cosine
its a periodic function so its not like it changes as you go out further
oh i tried it and its weird
theres a gap
this loops fine tho
ig bro
idk, periodicity isn't a part of a polynomial so actually eventually will eventually fly off to +inf or - inf. But what you said is how computers calculate sine and cosine, its range reduction.
yeah cause the approximation at x=pi isn't perfect
I’ve literally never been so confused
In the future, please use the ,rotate command.
,rotate
Looks good so far. I'd use $\cos 2\theta=\cos^2 \theta-=\sin^2 \theta$ for the denominator.
Civil Service Pigeon
Then consider what you can divide the numerator and denominator by
I am looking for a Gina wilson worksheet?
Searched her up, she’s the writer behind something called “All Things Algebra”
I don’t know that textbook/workbook but Mrt.231 is asking about that
Anyone got state testing next week
What state are u from
Nj
Omg me too
I assuming u are a freshmen right
8th grade
thankfuly no my state is doing testing rn but high schoolers onlu have to do it in 11th, i do have to trek rlly far to another classroom since my precal class has a lot of juniors testing and the classroom being used
Are u from NJ
ehhh i didn't rlly study for 8th grade state testing either, im sure you'll be fine. glgl!
They giving us 40 questiobs this time and the practice tests were hella hard
Questions
But gl
oof icic
for math english or science?
what is it
Srry that was my friend
Ohhh friend me
I hate vectors without coordinates
Why? They are easy
is there even a general method to working backwards my geometry problems? i feel like i can not work backwards due to 1. requiring theorems i learnt last year and even b4 which i forgot 2. these proofs being extremely nontrivial and requires a combination of the above theorems. My teacher recommended me to learn how to work backwards and analyze these problems but i cant seem to do so
for example this
Translation
Let ABC be an acute triangle (AB < AC) circumscribed by the circle (O;R). The altitudes AD,BE intersect at H. Let M,N denote the intersection of the @jovial sinew BE , AD respectively (M != B , N != A)
a) prove ABDE is cyclic, find the centre I of this circle, then use that do prove DE is parallel to NM
b) Draw the diameter CK of (O), prove ABKH is a parallelogram and H,I,K are collinear
c) Let BCA = 60 deg. Prove |DE| = 1/2 |AB| and calculate the lengths of the chord DE and minor arc DE of (I) wrt to R
i am stuck at the second part of A
cant figure out how to prove is parallel to NM
like not even able to work backwards
Working backwards gives you something to start with instead of looking for smth unclear . Say, showing parralel, you would naturally ask which theorem you have learnt related to parralel segments, here first thing to come up in my mind is BPT, and what's required? Same angles or ratio ( basically similar triangles ) if so, how would we show 2 angles share the same measurement? Here we have circles so maybe something with circles. We are actively working backward here
1 what is BPT exactly, English isnt my native language
2 yes but i cant find the relavent theorems to the problem at hand most of the time
Tho geometry is just like any topic in math, the ( in my opition ) most important thing you need is the intuition built up from solving problems
Yeah right, we call it Thales Theorem
... Thats the intercept theorem?
Idk man screw these names
You just lack the intuition, dw,I suggest write down every single theorems you have learnt on a paper and look at them whenever you solve a problem. If you can remember them right away then that's great. The goal here is to build the intuition
Định lý Thales xD
... Twin i didnt know your vietnamese too
:3
wait did you use fricking google translate
ofc not
I used to suffer from these euclidean geo
I feel you mate
what
oh ok
Can you guys use p1p2= √[(x2-x1) ²+(y2-y1) ²+(z2-z1) ²] to find the center of a circle?
or do u have to use the (x-h) ² one
for 2d use (x-h)^2 for 3d use euclidian
😔 what if we don't know the dimension
circle exists on 2d only 🥀
why do you use z here
... That's what was in the review sheet
Why not use $r^2=(x-a)^2+(y-b)^2$ for the circle centre formula?
It just said distance between two points
Minλ
Interesting, but isn't the third variable redundant, at least in the 2D space?
Is it different from the x-h one? Isn't it js the variable name
Is this for 2d?
yeah
Yes
Yes, unless you ask for a "sphere"
Minλ
So the r for the second one is √11?
Isn't it just x(x-4)+y(y-4) +z(z-4)?
Minλ
for the thales theorem/intercept theorem/BPT/whatever this is, it says that
$$AC \parallel DB \implies \frac{| SA |}{| AB |} =\frac{| SC |}{ | CD |}, \frac{| SB |}{| AB |} =\frac{| SD |}{| CD |} , \frac{| SA |}{| SB |} =\frac{| SC |}{| SD |}$$
however is the converse true?
$$AC \parallel DB \Longleftarrow \frac{| SA |}{| AB |} =\frac{| SC |}{ | CD |}, \frac{| SB |}{| AB |} =\frac{| SD |}{| CD |} , \frac{| SA |}{| SB |} =\frac{| SC |}{| SD |}$$
... What is this
Okay so a is 2
multiplexer
meth
both are 2 too
correct
So you have to add 3 times of 4 and minus 3 times of 4
move -12 to other side of equation, we have -11+12 = 1, that is radius
Unecessarily true, only holds iff the points laying down in the correct orders on the same sides of the vertex S
wdym in the correct orders
Suppose you have points D C on the line DS, if you reverse their orders, sure, the ratios still correct, but the line are not gonna parallel anymore
ok sure
thx
wait but hold up
wont they just intersect?
if they dont intersect thats fine no?
You want AC and BD to parallel, not crossing each other, and for thales to work, they must parallel
hmmm okay but i wanna prove the converse
like in some problems
""if ratio then parallel"
not "if parallel then ratio"
if you know what i mean
isn't it already a statement, no?
hm?
nvm i was trying to ask about the application of the converse thales theorem to this problem, specifically a)
You don't really need talet for a?
how do i solve it then?
chứng minh đồng vị
then what
vậy DAB=MAB, mà MAB= MNB do cùng chắn cung MB, nên DAB=MNB
=> DEB=MNB
bên còn lại y chang với góc EDA và NMA
SO ITS FRICKING ANGLE CHASING ALL ALONG?
là qed
thường câu a chỉ là tìm góc nên khá dễ
blud
còn tâm đường tròn chắc ngon r
Ooo okay
Good afternoon. For a project I am researching billiards in different objects. While focusing on billiards in an ellipse, I found out about Poncelet Porism, which I understand up to some point. However, the papers I've read then jump to a different concept called the 'Poncelet grid', which takes a poncelet $n$-gon inscribed by an outer ellipse $\Gamma$ which is inscribed by inner ellipse $\gamma$. Then taking two edges of the $n$-gon that are a fixed index $k$ away and taking the intersection of their extentions, you get a set of points $P_k$ that all lie on a confocal ellipse. The papers I read just claim this without much explanation, as if the result is very logical from what was discussed before, however I cannot find the logic behind them.
I can individually prove that given two tangents on an ellipse, you get that their intersection lies on an ellipse depending on the difference in the parametrization of $\gamma$. However, this implies that they are notconfocal, since their foci are scaled by parameter $\sec(\delta/2)$.
I also know Graves' theorem, which states that a constant-length string wrapped around an ellipse pulled taut traces a confocal ellipse. From this angle of proof we would need to show that every point of $P_k$ preserves the length of this string, which I struggle to find at this moment.
Could someone perhaps help me understand how this works?
AwaknThundr
guys what book do you recommend for me to master geometry and trig before i move onto precalc
cengage by g tewani
I worship cengage 🛐
yessir
Nicee
and a jee student
Lol, 27?
Oh nice man
^^ im supposing ur older lol
good luck, and be disciplined and consistent otherwise you will regret it lol
Yess ^^
i gave jee this year, ill be giving advanced in 3 weeks lol
i had 97.3, 42.5 rank
Thats rlly awesome ^^
general male but i have delhi HS so ill prolly get DTU mech
nah bro, if youre general male, even 99.5 doesnt guarantee best thing
exactly man
our situation is fked, we gotta work hard
or you can manage 98+ in mains and work your ass off for under 2k in advanced
Fr
Good thing im talented enough for my age
🥹🥹
I just need to build discipline
I know it will be tuff but ill stay strong
😌
ayy lets go
Hehehe
keep working hard man, even i though im too talented ill surely get under 10k but that did not happen for whatsover reason
Thanks man, appreciate it, and likewise!
See ya bro
Where to find trig Questions. Word problems, Any resources
khan academy
or youtube
or ask google
any ai can give you problems to solve
but yeah
youtube content creators also explain trig
or this
yes
!noai
Please do not trust ChatGPT or similar AI tools for mathematical tasks, as they often generate output which "sounds correct" but has numerous factual or logical errors. Use of these AI tools to answer other people's help questions is strictly against server rules (see #rules).
Is this bot talking about not trusting bots
ok thanks sorry im new here
You dont "have to" give the JEE
It has very to toxic culture around it, especially when it comes to the subject and the way you are asked to rote memorise.
Real
its too much hyped up by coachings to make tons of money and pressured by parents for respect in society
CENGAGE MENTIONED 🗣️ 🗣️ 🔥 🔥 🛐
θ
how do you get that
either charmap ,copying from some unicode site or greek keyboard
Honestly speaking, Out of 14 lakhs students who write it, Only 2-3 lakhs are actually serious about it
2-3 lakh are serious and working, next few lakhs prepare but get a reality check
last 2-4 lakhs just filled the form for fun
Facts
Did u write jee?
Yeah
wbu?
Na I started my 11th grade this year
Did u write it this year or are you already in college?
also, Any tips?
i wrote last month
if you are serious about it - discipline and consistency.
Its so hard to be consistent honestly
Ever since boards ended, i have kind of been distracted
school only starts in june
i few days break is fine, but when you are back at it, dont stop. leave no fking stone unturned
Results of mains came out right? Are you writing advanced then?
True
yeah im writing advanced
result hasnt come out yet bro 💀 im writing
no idea what will happen
97.3
lmao what was your rank?
mine was 425xx
damn no way
2s2
mere do dost hai, ek ki 98.2 and 98.54
their ranks are 27k and 23k respectively
so hows your 21k 😭
sir what?
you cant be serious dawg
btw shifts are normalised and age is no longer used in tie breaker
Anyone have a good geometry question?
the answer key says that the height of the COM is r(1-cos(θ)), why is this?
as i remember, cos(θ) is adjacent/hypotenuse
and i tried experimenting in desmos, and it does hold true
but i still dont get why
The change in h is the initial depth - final depth
The final depth is rcosθ, and since the center of mass always stays at r from the pivot point, the initial depth is r
From that, find Δh
oh I see, its actually just r-rcos
Mhm. Which is the same as r(1 - cosθ)
question regarding sines
what stops someone from making a formula for sin(ϴ/3) using the formula for sin(3ϴ) and the depressed cubic formula?
You could, but it would be quite useless
The cubic formula requires you to compute a cube root of a complex number
To find the cube root, you need to use De Moivre’s theorem, which in turn requires calculating the sine or cosine of an angle divided by three
Which gets you right back where you started
not the cube root but the roots of a third order polynomial
isn't there a general formula for that?
Yeah
The cubic formula
… which involves cube roots.

can someone help me with this
they um say the steps
the point P refers to the center of the circle
from there any point on the circumference of the circle connected in a straight line segment from point P is the radius, PQ
then use the compass to go from there
and the next few steps would explain it
ight ty
would vectors be considered geometry
Depends on how abstractly you're working with them, but if you're asking here rather than in #linear-algebra, then the answer is most likely "yes".
I mean they’re also a precalc topic
Can somebody explain to me the relationship b/w imaginary numbers and trig functions
Like i heard in some class that i(iota) is just 90° rotation
And trig works with degrees
How do people understand geometry without loosing hair? (Seriously, I spent alot of time but still i cant seem to understand it)
Once you get the hang of it, it'll be easier
One of the major factor of being good at geometry is just having good memory and familiarizing other formulas that might be a solution to the problem
This is how I do it idk
Idk how to explain better but think of a circle with the center being the origin ad its radius is 1
Look at (1,0), if you multiply it by -1, it would be (-1,0)
Therefore multiplying by −1 corresponds to a 180° rotation.
Now look at i=√-1
i²=-1
So:
doing i twice gives 180° total rotation
That means:
each i step = half of 180° = 90°
Soooo (1,0)(i)(i) should be (-1,0)
Qnd (1,0)(i) should be (0,1)
Am I making sense or am I hella confusing
1, -1, i, -i make a circle in the graph
if you connect them
Thanks i remember a video which explains this, you've helped my revise it
woah
Why is this guy under so many supervisions
<@&268886789983436800> really suspicious person
No actually this is a textwall
Even here 
Does anyone know how to find trigonometric angles? I'm fairly new to trigonometry, and I haven't gotten the baseline of triangles and such (ironically enough, I take calculus, which has and goes over trigonometry). Can someone give me a step by step on how to find an angle like this?:
(I know the Pythagorean theorem, but I cannot execute it.)
What do you mean by "find an angle" when it's given in the diagram as 43° explicitly?
Do you mean the unmarked angle? That must be 180° - 43° - 90°, due to the angle sum of triangles.
which angle?
if you mean by the missing one then do it as tropo said
stuff like that. i mean, i don't know specifically what i want to solve, but i want a clear way on how to since most of the time trigonometric angles have sides as well, and you have to execute both to get your answer.
i didn't clarify this before, but that's what I meant.
Yea, pretty much but theres still something I kinda wanted to be answered, in which I already asked Tropo
this?
Yea something like that
I'm afraid I don't understand what your question is.
just take the sin/cos/tan of the angle as needed and use the chart above to solve duh.
So, I was asking just how to solve stuff like that in general. Like a step by step guide on how to solve an entire trigonometric question
Okay
trig is an incredibly diverse subject
so that question cant really be answered
I don't even understand what "stuff like that" means? The only stuff you have shown was a diagram where the angle was given explicitly, so there's not even anything to solve there.
Sorry, I didn't know it was a diagram. However, you could answer that diagram yea, but the thing is I wanted a step by step guide on how to solve them. Like how to use the Pythagorean theorem and such and execute them to solve actual trigonometric problems.
Sorry, I didn't know it was a diagram.
Um, wut?
for these kinds of questions then
notice how this can be directly derived from sohcahtoa
well c is just the pythagorean theorem
Okay! Thanks for helping me, and sorry for the confusing explanation D:
Can someone explain why my first approach isn’t valid?
The 2nd approach leads me to the correct answer as I’ll just do sqrt(17^2 - 15^2)
Then do 12 - ^
First approach is the one on the left right?
You cant just assume BC = 8
Didn't he do the pythagoras theorem to find it out?
What you do is smh computing AD-BC (which you did in the second one) and then use that to find out BC
Yeah I did
Yeah I didn’t assume, I did Pythagoras but I’m struggling why it isn’t valid
That doesn’t tell me where I went wrong tho, that’s obviously the 2nd approach I’ve done
How did you get 17 in the first one?
Yk how DC = 17 I assumed that line across would also be 17
Define C' (projection of C). you assumed C'B = 17
There is nothing saying that DC'BC is a parallelogram lmfao
But i don't think you can assume it like that
Yeah that’s fair enough
Idk why i approached it like that but fair I get it now
The exercise didnt give DC' and BC are parallel and equal, u just assumed that
Yeah true
Cheers guys
Congrats
Could i pls know the answer?
Nice one
Yea thats what im thinking
Hey guys, I wanted to ask whether it's possible to represent 3d rotations in tilted planes centered at the origin as rotations in the independent planes that make them. For example, if we want to rotate a point (any point) in a plane that is tilted from the positive z axis in the YZ plane by 20 degrees by 45 degrees (in that plane), can we represent this rotation as first a rotation in that YZ plane and then a rotation in a base plane like the XY plane in this example by 45 degrees. Or switch the order of rotations as 3d rotations are non commutative.My question is, if this is possible how do we find the necessary planes to rotate in (XY, YZ or/and XZ), and the angles to rotate by?
oh and the order in which to rotate in those planes by?
oh sorry
I wasnt sure to be honest... I've been working with a lot of the sin cos and tan ratios, as well as the tip to tail and tail to tail addition/subtraction rules I thought I would ask here
I feel as if I also shouldve thought of this since im literally in the vectors part of my calc+vectors course rn... 😭😭
my excuse is i'm sick and my brain is mush ✌️🥹
does anyone know the equation for how many unique faces you can form using n vertices? including intersecting ones
from what i can tell the relation of vertices to faces goes something like this
1 vertex : 0 faces
2 : 0
3 : 1
4 : 5
5 : 26
6 : 54
6 could be wrong but im pretty sure im right about the previous ones
i think there's a factorial term to it somewhere but idk
quick sketch of what i mean for 4 vertices
The upper left and lower left and lower right are the same in different rotations, so you shouldn't multiply them all by 5.
I would count it as "all the ways to select some of the vertices, except the ones that select only 1 or 2 vertices, or none".
That yields 2^n - 1 - n - n(n-1)/2.
awesome
surprising that that’s not a factorial since i all combinations of n values is usually factorial
i also see the formula for edges in there
So I get this result:
$ perl -l -e 'for $n (1..7) { print "$n ",(1<<$n)-1-$n-$n*($n-1)/2 }'
1 0
2 0
3 1
4 5
5 16
6 42
7 99
ok i was initially right with 16 faces for 5 verts then
Presumably we don't want a "face" whose sides cross each other, so once we've decide which vertices we're using, there's only one order to connect them in. So we're interested in subsets without ordering. Factorials are for when the order of picking matters (or else we need to correct for overcounting later).
ic
<@&286206848099549185>
It's been like 50 minutes i swear, i can ping now right?
this is an open ended question i think which is against the rules to post in help channels right?
cuz there is like not really one answer, idk?
anyways, can anyone help me on this?
plzzzzzz
pretty plzzzzzzzzzz

hey, could u like provide a direction to pursue in this question, like is representing 3d rotations in this manner possible and how might I try to do it without mixing up the order of rotations?
I have no idea how, but asking random ppl and posting textwalls aint gonna help you
but you just helped someone on their trig question. : (
As they said, helpers are volunteers, we choose whether or not to help
IG I will have to open a help channel now, even though I think it's against the rules for open-ended questions but okay
ig you have a point
okay
well, here is the link :https://discord.com/channels/268882317391429632/1499084623739748452 if anyone wants to help, they can do so here, regards.
Check my work
I came up with 105 as well
And I did it in a different way so you're good 👍
Triangle is 180°
55 + 50 = 105
180 (triangle) - 105 (2 of three angles) = 75
180 (flat line) - 75 = 105
PLLLLSSSS
what do you have to find
oh x I see it now
ok so is ABCD a rectangle
so angle ABK is 36 degrees
wdym
ok
so EC is an angle bisector of course
is this correct?
This makes no sense
The tangent-secant theorem applies when the tangent and secant meet outside of the circle
Also you don’t even have a tangent with what you used
Consider this triangle
i thought AB is a tangent?
Tangents meet the circle at exactly one point
AB meets the circle at two points: A and B
Looks more like a diameter on those pictures ...
it is
guys
can someone help pls
its a kahoot assignment, its not a test or anything
idk how to get x
can someone help: i got 63 for Abe idk if its right
ohhhh is it ratios?
lemme look
You could write it as
$$\frac{PA}{PC}=\frac{PD}{PB},$$
which is an equality of ratios.
Civil Service Pigeon
yea, i got 63
because the 86 is inscribed with abc and then you half it and then you add it with 20 which equals 63
Hello?
hey pigeon, i did this thing and i got it wrong
because i got 7.5 and the answer was 4
!show
Show your work, and if possible, explain where you are stuck.
ok
... actually do either of those make sense
i did
6/8 = x/10
and it gave me 7.5
but the answer was 4
i did that because of the ratio thing u sent
because if the numeric lengths correspond to these highlighted things
then you should use the intersecting chords theorem
well this is also a different configuration tbf
you can't apply theorems in places where they don't apply
`the secant secant theorem applies when you have two secants
you don't have two secants here
you have two chords
yea, i used that for a dif one
the secant thing
i used the secant one for this one
and i got it wrong
no, that was the next problem
and i still didnt know how to do it
bc circles r hard
how would this one work?
Read carefully - PA and PC are the parts of the secants outside the circle and PB, PD are the entire secants
so it should be 6/8 = (6+10)/(x+8)
oh
so i just did part and part
not part and whole
thanks
how would this one work tho?
oh sorry
help meeeee
pleaseeee
im so confused
are these right
@exotic yarrow
You good?
?

:(
straight recall, though the proof is also quite short tbf
Also bearing depends on that
Like shape “c” and “z”
That’s what I found
What’s this now
Are you trying to draw a parallel line and do something with the alternate interior angles theorem or smt ... ?
if so, you should have these pairs of angles - your diagram has incorrect labeling.
yeah see what I said above then
Okay
What are some advices of this bc I’m having a quiz on Friday
basics of vector algebra?
Never did
but i see some diagrams involve directions and may be magnitude and angles
so
ok dude my bad homie
It’s okay
Bearing is an angle
Btw
help pls
You found how many turns each gear will do ?
yes
The angle for the gear with radius 3 is 2π and the angle for the gear with radius 2 is 3π/2, right?
How can i create laggy stuff in desmos
Use sum, prod and floors func
Also trig xD
I know sum and prod but whats floors
Wdym laggy?
Like very intricate stuff
Oh nice I didn't know that word
Floor(x) return the greatest integer less than or equal x ( fixed :p )
Elaborate please
Ok i choose 3
And why not 3?
Cause im dumb idk what an integer is im in 6th grade 
Integer means natural numbers but their negative version as well
Oh okay
So 0, 1, 2, 3, ... and also -1, -2, -3, -4, ...
@queen glade
Read this one more time
Correct. Do you see why 2 wasn't correct?
Because it wasnt equal to 3
Yup awesome 👍
Yay
I think that :
The gear with a radius of 3m does a 60° rotation (counter-clockwise)
The gear with a radius of 2m does a 90° rotation (clockwise)
So the floor of 3 is 3 itself
What about the floor of, let's say, 7.3?
7.3?
Since g3 did 1/6 of its rotation and g2 did 1/4 of its rotation
Nope, 7.3 is not an integer
Yup perfect 💪
Okay i get it thanks
Yw
So the floor of pi is 3?
Exactly! Very well 🤗
$\floor{x} = 3$
Alberto Z.
[3.2] = 3
Okay
Btw floor(-2.3) is -3
Oke
Yeah good observation
Which is kinda funny
Negative numbers get less the further you go
exactly, good one
Especially due to the fact that sometimes floor is compared to integer part. But this is true only for non negative numbers
I have another question now 
Okay, so you take the largest of the two numbers on each side of the dot and preserve the sign, right?
Whats ceiling
You can probably guess it
The integer above or equal?
ceil(x) return the smallest integer greater than or equal to x
Okay
Ceiling is
where floor is
.
Okay
The lowest integer above or equal, yeah
(As shown by Alberto's reaction).
Okay
You can also describe it as "if it's not already an integer, round up (for ceiling) or down (for floor) until you reach one".

Fun puzzle: Solve for all solutions of $\tan x = x.$
LemmaLover
I doubt the solutions of that have any nicer description than "the numbers for which tan x = x".
There's exactly one within pi/2 of every integer multiple of pi, and the distance between two successive solutions is always more than pi, but beyond that?
how do you even begin to approach this
solve for all solutions of x=x ahh
@stone lark do you still want to know how I found these values or no ?
who can help pls
sen is sine?
yes
do you know trig identities
I got the result that g3 rotates 1/6 if gears g4 and g3 are connected by a pulley.
But g4 is connected to g1 by a pulley, not to g3.
I didn't even notice that there was a g1
Yes, sorry for the delay.
That's why this problem has me so hooked.
What is the kind of connection g1 has with g3
a common axis
G4-G1 is a pulley
G3-G2 is friction
yes
Both will have the same angular rotation
Knowing that you can find the arc of the rotation
You are complicating your life a bit too much
So 1- find the distance of rotation of G4
Or you can directly skip that
G4 does 1/8 of its rotation
Since G1 is 4x smaller it will do 1/2 of its rotation so 180° or pi rad
With that you can continue the problem
(I think that) I solved it if you want to see how I did it
I would really appreciate it, bro
I'm sorry I had to do it on paper because my laptop is dead
Hope its readable
And understandable
Oh, so the movement of P2 and P3 originates from point P
I thought they started from where their radios were initially marked.
That's what I've understood
That certainly make the problem a bit harder
Well, they may not have framed the problem correctly; doing it the way you did makes a lot of sense.
It could've been explained a bit better I won't lie
G1 being on the rotation axis as G3 was mentioned nowhere
yeah thats so weird haha
I'll stick with how you did it, now I'll continue practicing with other exercises, thanks a lot bro.
No problem and good luck
does anyone have a good practice book for trig problems
Most people don't know who created the hardest chapter Trigonometric Ratio
who created the hardest chapter Trigonometric Ratio
Aryabhatta
Most prebably
Most people also don't know who solved the general formula for cubes
Say who
@willow kiln Say who!!?
its not even that hard wdym 😂
its a piece of cake
Tell that to Aryabhatta
Hi
For finding point of concurrency of three lines can i just solve the lines the traditional way or should i use the matrix method
i am super stupid ive been slacking all year just using ai and getting good grades on my math stuff but now i have a huge geometry test in 4 days and i dont know a single thing on it and im gonna fail like no one has ever failed before im trying to learn the entirety of geometry in the next coumple of days can anyone help me or gimme like some pointers or some yt vid links on how to learn geometry cause im watching like the organic chemistry tutor and stuff and its just not clicking to me can smn plz help
Matrix with Gauss-Jodran would be faster
I think I can help you to go over what you don't understand
Also try to get the notes of your classmate if possible
Struggling with this question
Surface area I get is 22,000cm
It wants 5 shapes so 22,000 x 5 = 110,000
6m^2 to cm = 600 x 600 = 360,000
So it would be 1 but it's incorrect. I'm going somewhere wrong in the 6m^2 calculation but can't see it
use total surface area
u will get 2.2 msquare for one
so for 5 it is 11 msquare
then 11 divide 6 is 1.83
which is roughly 2 pots
As a helper, please do not give out answers that could be copied as a homework solution. Have the student work through the problem themselves and guide them along the way.
sry my bad boss
Don't worry, it's fine.
This isn't the case, but sometimes there are ultra lazy people who come here just to have their answers given, and we don't like to do that
my brain is not braining but if you had 2^2 it's 2 * 2 = 4
so surely it's 600 x 600 (600cm in 6 metres)
what am i doing wrong here
aa think more clearly
its 6 metre square
not 6 square metre square
or 6 metre whole square
The square is only written in the m of meters, not on the 6
What is this math slop
prob 114
Opposite angles in a cyclic quadrilateral add to 180° due to the central angle theorem; from threre it's just iscosceles triangles and a bit of algebra.
I could do it, but im too lazy
Ah, then I'll be lazy too.
First recognize that the double dashed isoceles triangles other angles are 38° and 104
Therefore the opposite angle to it is 76
The angle next to the 76° angle is also 76° due to isoceles
,calc 180 -(76+38)
Result:
66
,calc 180-66
Result:
114
And this is our result, x = 114°
It is 114
hello i need someone teaching me calculus 1 chapter 3 please I HAVE A MID EXSAM
i need to understand it as fast as it gets
Someone ought to have been paid to teach it to you in digestible chunks spread out over the semester leading up to the exam ...
Also, yes #calculus.
Logically it would be 114
i js had a circles test today
ts is something we learned
but something like this would be too easy on the test
Mf i found ts on youtube shorts
same
but most of yt shorts is under 10 so there's probably like a billion wrong answers

for negative exponents? what about -2 lol
~~ 1/arctan ~~
don't think they ever get used,
people use reciprocal functions or fractions for that
Hello I am an IGCSE student 11th grade and im studying trigonometry and im looking for help. Its weird and makes no sense and I am just looking for help in making sense of trigonometry at this stage.
Post specific questions you have issues with
Be specific
Its the graphs of trigonometric functions chapter.
Can someone hop on voice chat if possible? I would perfer that
i can try
maybe their teacher is bad
how do i get my line to fit the grid line on desmos
whats the equation of your line
sin(5pi)x=y
Whats the equation of the closest grid line anyways
i think its 1/sqrt3 *x
Wait no i meant to type sin(pi/5)x
tan30
Huh okay
guys
i forgot how to differentiate can u guys help me recap rq I'll send basic qns
so it saves me time to do the basic questions myself I can skip to the intermediate ones
can someone help 
!help
To ask for mathematics help on this server, please open your own help channel or help thread. See #❓how-to-get-help for instructions.
hi
okay thanks
rate of change of a curve
that is precalc i suppose
"How to differentiate" is definitely calculus, not pre-.
Uhh "differentiation" without context sounds liek calc
Differentiate is it supposed to be d/dx?
I believe that term is for year 11-12 maths
I’m kinda a desmos newbie so how do I get the circle graph
Click on the wrench your should find the circular grid
Ok ty
The problem assumes a simplified calculation
So the lengh of the pulleys are not considered
Solving it properly, you should get the masses' coordinates
put them in a matrix and define the area as the module of the determinant divided by 2
but as the problem expect you not to use analytic geometry, you simplify the quadrilateral, getting a trapezoid
is it like find the area formed by n, after the belt move 1 metre
Oh I thought this
yes its like that
correct anwser is around 6,6m^2
How did you solve it?
to get the vertical diplacement, you need to see that each circle has a circular displacement(x in metres) and an angular displacement (theta in radians)
as the 4m circle has a 1m circular displacement, you can calculate the angular displacement
as the 2m circle is inside the 4m one, their angular displacement is the same
so you get the displacement you got
-1/2 and 1/2 for the left ones and -1/3 and 1/3 for the right ones
now you plot them in a cartesian grath and set a reference for y (in my case, the original mass positions)
so the y positions would be (-1/2)(1/2)(1/3)(-1/3)
to calculate the x positions, you use the pythagorean theorem to find the axis distance
it will be equal to sqrt(63)
I'll send an image, just a sec
So, to find the x positions you use the radius of each circle (x1 = 0)
the yellow line is the y and x axis
GET OUT
x2 = 4
x3 = 1 + sqrt(63)
x4 = 3 + sqrt(63)
so now, you have the four coordinates
use analytic geometry to find the area
are you familiar with analytic geometry? @stone lark
Not much since I'm just starting to study it, but if you'd like, continue down that path.
I think I've already seen my mistake.
there is a formula for every shape since you know its coordinates.
you use it and get around 6,6
idk why are the alternatives so different
probably a bad printing in the alternatives
they probably subtracted the diameter of the circles so you get a trapezoid
What was it?
spam
@sleek ridge bro thx so much
anytime
wouldn't it be ||29 and 151||
When I did transversal rule
how did u use transversal rule on ts
i dont see parallel lines?
Then it’s right angle
like x and the like other angle next to y are equal
cus isoceles triangle
Yes
Like this is this correct
So Jake, have you learned that the sum of a triangle's angles has to be 180 degrees?
Yes
i got like 58/2=29. um. maybe they meant to divide it by 2 idk
Oh wait I divided incorrectly, my bad
I was thinking 52 in my head
x + 32 should not add up to 90, as that is not a right angle
Also ik the proof is side then angle
ah
Okay. Because that triangle on the left is isoceles, then you know what?
Did you find X = 58 ?
Yes
Because I'll tell you, x is not 58 degrees, but 58 degrees is important somewhere
It’s this
Then the outer part is “58-x”
If you think about it... if you have 122 as one of the angles of the ISOCELES triangle
What are the other 2 angles in that ISOCELES triangle... hmmmm
Then it equals 90
My idea was make it 32+58+(58-x)=90
Uhh
well 32+58=90
90+58-x=90
148-x=90
....err... yeah this is....
questionable
just... it isn't necessary
x=58
OKAY lets say x=58
then what would the bottom right (theta) be
if 122+58=180
then theta would be zero
Dawg
Angles cannot be 0
So would it be 58+x
um...
.....
how about we go back to thinking
if you have 122
in an isoceles triangle
the other two angles add up to 180-122 and should each be the sum / 2 cus they are equal
If you just consider the one triangle, you end up with this
Ohhh
Can I make a right triangle then figure out
Do you see how the angles are the same because the triangle is isoceles?
Yes
a right triangle is unnecessary to solve this problem...
Maybe you could, but you're making it harder than it can be
Solving math problems is often about breaking problems into smaller chunks.
Once you figure out that one angle is 122 degrees, and you identify the triangle as isoceles, you should only look at those two facts. The rest of the problem essentially disappears until you figure out what x is. At that point, you're just left with this
I mean, I think what you're saying is clever, and technically accurate, I see what you're saying. Whether you can solve for x, I mean it introduces another unknown because you have
x + y = 58
32 + x + y = 90
Solve for x, but you don't know y
You know what I'm saying?
Is it because the proof “if side then angle”
there aren't any congruence theorems if thats what you're saying?
Yea
How did u get x+y=58
Just because of how you setup your angles
I got y=0
y is not 0 in that case
Bc I substitute x=58-y
Let me show you what y I'm talking about
32+(58-y)=90
so the idea is x = 58-y, 32+58-y+y=90. y isn't 0, just canceled out
that woul just lead you to 90=90 btw
which doesn't help
thats why a right triangle is unecessary
cus it doesn't help w/ the problem
x+z=58
^
Without more information, I'm not sure you could say anything about x and z
That's why I'm saying focus on these facts instead
(1) One angle is 122 degrees
(2) Triangle is isoceles, and because of that, the other two angles are equal (theorem)
(3) All angles add up to 180 (theorem)
From that you can make some clear deductions
How did you get that z is 58??
mmhm
Yep, there you go
right! yey
I used that
my teacher never taught us whatever bearings are but nice
It’s an angle of on a compass
oh
N,E,S,W
the parallel lines aren't neccesary tho
But this can help
it vould work but help is sort of well…its faster probably and easier just thinking with isoceles triangle
Ok
erm
why is there a right triangle
the sum of angles in a triangle is 180
it's an isosceles so the angle X is also the angle there on the bottom so (180-58)+2X=180 => 2X-58=0 => X=29, Y=180-29-151? am I stupid or something
watch a youtube video
looks like there is not enough info, since the width of the box is unknown
yeah thats why i assumed that the corner is connected to both centers of the circles
Doesn't seems right.
anyone
There just simply isn't enough information, lol. If you assume the angle between the centers of the circles you can figure it out, but otherwise, no
I just want to make sure that if it’s Isoceles is it two angles and two sides are congruent
I had these
• If sides then angles.
• If angles then sides.
as part part of my geometry proof
yeah there's no way to get a concrete solution, you can only assume 
the sides are marked as congruent already, no?
Yea
Hey guys I am stuck on my math hw and need some help 😓😓
I’m mostly stuck on how to find the angles of the triangle and would appreciate a in-depth explanation if possible ;;;
Have you learned trig laws? like law of sine/cosine
cus since theres no right angle, im pretty sure u have to use ... law of cosine, i believe
Not yet but I tried turning it into a right triangle like this to solve it. Would this help or would I have to search up law of cosine 💔
Hmm, let me think if that would work.
hint: this might help

