#geometry-and-trigonometry
1 messages · Page 106 of 1
aare we talking about sine of sine of theta
nope
on the graph
we are just talking about sine of theta
sine has to be symetrical (sign independent for input)
ye
nope
thats cos and sec
It ise
that is not symmetrical
The amplitude of a sine wave is between
-1 and 1
why though i get why sin theta has to be between -1 and 1
but why does the sin(x) output
have to be
help pls
The graph and and sinx is telling the same thing
i think maybe u find the central plane find theta and use sin theta maybe
i get it
but why is sin(x) constricted to -1, 1
i get sin theta
because there hyp is bigger
but sin(x) isnt opp/hyp
How can you have a hypotenuse bigger than the opposite ?
It literally is
were not supposed to use trig for this prblem
i thought its some infinite series
For you it isn't
sin(theta) is opp/hyp i thought? is sin(x) = sin(theta)
All that is higher mathematics which you won't get unless you understand the basics
Θ and x are literally variables they could be anything
demk
then why send it here?
yes so i dont get why sin(theta) is opp/hyp because i dont get the sin function but are you saying i cant undertand it until later
The sine function is opp/hyp
sin is a ratio yes
so how do u plot opp/hyp
To help you get it
The ratio opp/hyp is coined as sine
ok but isnt the ratio of sine different from the function sine then
i get the ratio of sine
To understand the graphs of you need trig function you need to wait
its defined as the raatio between opp and hyp
They are literally the same thing
Yes finally you are getting it
yes but how do you express that as a function
because a functio doesnt care bout triangles
or anything
It is a function you doughnut
ok sin(theta) simplifies to opp/hyp somehow right?
but what is it originally
what does it do to the input
and i was right about how u were finna crash out
IT DRAWS A TRIANGLE AND FIND THE RATIO
All right you doughnut listen carefully
The ratio opp/hyp is called sine
It isn't derived but rather named
You don't solve 100 pages long equations to get that sine is opp/hyp
I mean this kid thinks that what he's being told isn't right and being presented in the wrong way and had the wrong understanding of everything
yes thats ratio sine i get it ratio sine is just a name we gave to a ratio
lel
Yes
You are finally getting it
im trying to understand 😭
tbh every function is just named fr
Yeah
on the difference between sin function and sine ratio, sine ratio is just discovered and named right i get it but the function sine isnt a ratio, rather its a function so what is the function sin() y=sin(x) sine the ratio isnt sine(x) sine the ratio just means opp/hyp of a right angle triangle i dot even get why you start talking about some sin(theta) when theta (the input) isnt even in the function
ye alr i quit but ye u didnt quite teach him that
That's where you are wrong I'm sure that you don't even know what a function is
a function takes an innput x and produces an output
sin(theta) isnt doing that
What do you think a sine does?
why do you need theta
you can see the opp/hyp from any triangle
anyways
if theta is marked
so it should just be sine of triangle
You can't? A hypothenuse is defined for right triangles
the input theta is doing nothing
.
It literally is what makes triangles different for different angles you'll get different lengths hence different ratios
You have no idea of a basic geometry
No wonder
Tbh he isn't not that level yet
the definition of the stupid function is f(x) take x and make output so then if you take any angle theta as input say 30 tthen you aarent using it in opp/hyp directly (i get that theta defines the triangle but then it shouldnt be sin(theta) as a function it should be sine of the triangle)
yes its dependent on that
but also on the triangles side length
and hypotenuse length
tru
Take these triangles for example it's clearly not of same sides but the trig ratios will always be same
which grade u in @gloomy spear ?
You from the UK?
u are too i presume ("doughnut")
ahhhhh ok ok
OMG in that case I'm done explaining it to you the gcse curriculum is a mistake I've seen it they reach high schoolers middle/elementary school maths/science
what if its opp/hyp and opp is a different size in the 2
I'm not
wdym
the GCSE curriculum doesnt go into depth
Exactly
i personally wanna go into maths heavy fields
well the ratio would still be the same
so im going into depth on my own accord
since the triangles are similar
That's why you are not getting what a sine is
i care about the math not the grade
Okay ig I was being rude i always encourage learning and curiosity
LEL
YES
Kinda
Lol
i learned it outside skl
ahhh
ok
so sine is actually based on similarity
thats why we say its equal if angle equal even for different right angle triangles
It doesn't matter what the length is as long as the angle right
because angles dictate length
in a triangle
Yes!!
basically
like ratios of lengths but whatevr
so then here opp and adj are swapped
to give the same thing
yes
Since the sum of internal angles of a triangle is 180°
ok so that means if a triangle has 2 equal angles (besides the right one) the sin of each angle will be the same
in both triangles
No really but
In that case sinx = cosx
That's why we can say that
Sinx = cos90-x
If the sides are not swapped
That's a 45-45-90° triangle
i mean in the first one if we keep 30 as theta
and then go to the second one
and 30 is still our theta
then the opp and adj are swapped
right?
which is what makes the sin the same
Yea that's kinda what I just explained
i get it now thx
Byee
oh here i meant if 2 triangles
These are from allied angles you'll learn it in the future
sry wrong wording
like if 1 triangle has 30-60-90 and the other 60-30-90
yeah
i get it why sin is based on angles
They are similar triangle m
and why it stays for similar triangles
Good!!!
Yessss
You finally got it
yes thank you
Welcome
what schooling system r u in?
what grade?
11
i can imagine
is that 15-16 for u asw
ye india, china, korea
are hardcore
Yeah there's an engineering entrance exam called jee it tests you on maths, physics and chemistry on level just below university
Yep
True
btw GCSE isnt our final exams before uni
its an intermediary
Ohh
Ohhh
GCSEs are easy lol compared to a level
Makes sense not everyone can get into a uni as good as cambridge right 😂
did u think UK skl was that dumb lol
I really did
a levels in comp sci are too easy though tbh
comp sci in the west
is too easy
not rigorous
Is that so?
yes at a level they dont even expect u to be able to build an API or even describe how a fullstack app could work
Idk about comp sci with regard to academics but I do also learn coding
what lang?
That's crazy no way
Right I'm not doing it as I'm focusing on jee but before I was learning JavaScript and python
That's nice
yeah i am proficient (can never say i "know" a lang)
at them
no one actually knows a whole language
I don't think even they know
Alright I'm going to sleep it's like 1:40am over here
gn
True
bye
Just started geometry and algebra (dont mind the smart score...)
cool! Do you need help on this question?
how did you come up with this?
Just substitute tan(4x)=(a+b)/(1-ab) into equation and factor out a+b and 1-ab in the numerator.
ooh thats clever
ik am very late but i dont like the way that this looks
Does anyone know a site or git or anything that compiles all known solutions for polygonal and polyhedral packings?
Or somewhere that has the vast majority of them in one place?
This is mostly like highschool-middleschool geometry yo 🥀
you're not going to find many people discussing that here
you never know!
am in 8th grade and was not expecting to encounter so many theorms in geometry , fun.
Hi guys, can you guys help me with this simple question, where did they get the 1+1 on the second to last step? This equation is being used in a unit circle, b1 and b2 are the coordinates of point B, a1 and a2 are the coordinates for point A
Not really sure if i ahve to open a channel for this since its not that hard of a question, i just got a bit confused and wanna get clarification
1 is the hypotenuse of A and B
in a unit circle, the coordinates are also the length of the sides of a right triangle formed by a coordinate
Yes i understand that but how did that apear in the place of a1^2+a2^2+b1^2+b2^2
pythagoras theorem
\begin{tikzpicture}[scale=5]
\draw (0,0) circle[radius=1];
\coordinate (A) at (0.87,0.5);
\draw (0,0) -- node[above left] {$1$} (A) node {$A=(a_1,a_2)$};
\draw[dashed] (0,0) -- node[below] {$a_1$} (0.87,0);
\draw[dashed] (0.87,0) -- node[right] {$a_2$} (0.87,0.5);
\node at (0,-0.5) {$a_1^2+a_2^2=1$};
\end{tikzpicture}
glass
here's one for A
ah i see
Thanks tho 😁
my god
idk how to write this shi
no idea
if you want to learn, you can read the first part of the TikZ documentation (check #latex-help pins)
then you can search it for anything specific you want. (Hopefully your pdf reader has search functionality)

what are you facing difficulty in? struggling to choose which theorem to use or remembering them?
I do not understand this question for the sake of me I tried solving it twice only got so far as in the height gets doubled but I don’t know where to go from here
Can someone help me? How do you solve these? 🥹 my teacher doesn't explain well
The surface area of the two prisms combined without overlap is 2K. However, the surface area of the resulting prisms is 92/47 K. This loss is due to not counting one of the square bases in the surface area for each prism. So, the area of one square base is 1/2 (2K - 92/47 K) = 1/47 K. See where you can get from here.
Also, google: https://youtu.be/UHWKPglwxpo?si=0kF9hAvSgz8mBea6
Nonadaptive Digital SAT Practice Test 4 Module 2 Question 26:
Two identical rectangular prisms each have a height of 90 centimeters (cm). The base of each prism is a square, and the surface area of each prism is K cm^2. If the prisms are glued together along a square base, the resulting prism has a surface area of 92/47K cm^2. What is the sid...
Recall that the distance from a point to the center of rotation is equal to the distance from the image of said point to the center of rotation
So for two pairs of points (image and preimage), you can find the locus of points equidistant from each point in the pair by constructing
Whichever point is in both pairs is your centre of rotation
There are 2 methods to find the centre of rotation or the pivot one is logic and other is to use perpendicular lines Mammoth_Memory_Maths for GCSE students
That’s the logic that they’re using here
I am not trying to find points. Idk how to explain it but here's my teacher's work
I am not sure where to start or what to do
What? The centre of rotation is a point.
It looks like your teacher is just doing trial and error on each marked point to see which matches the given angle of rotation though

In 35, you have points D, E, F being marked that aren’t part of the image or preimage
The implicit message is that one of those is the centre of rotation
So you test all of them, as I said earlier
Ex. Your teacher testing F by seeing what the angle of rotation would be about F from A to A’
This angle is acute
So that can’t possibly be it
They did a similar thin for E between B and B’
But that angle is way too big, so no
Then they tested D between A and A’
Which gives a reasonably 100 degree angle
Combined with the fact F and E are eliminated, that leaves D as the answer
oh I also noticed E and F are CW, only D is CCW 🫠 welp thank you
how r u so smart
help how do we get fdg
FDE = 180 - CDE = 180 - 138 = 42, FDG = 90 - 42 = 48
TYYYY we had figured this out by now tysm
Do you know how to get x
x is correct
draw arcs connecting the points
what is the center of these partial circles
looks like D for 35 and F for 36
can someone slide the rest of the identities this is all i have rn 🥺
there might be a few extras on here
heres a thing i wrote several years ago (section 6 is a bit of a showoff thing and you dont rly need to memorize those at all)
Man I started studying geometry personally three days ago. so much learning to do 🥹
you didn't mentioned the "tan(90-x) = cot(x)" one's if am right :<
yeah i suppose i didnt
:>
did u actually prove section 6 when u were that day years old?
yes
im currently using khan to learn. would someone be able to vc and explain what im missing?
we don't do VCs on this server
right, but this is discord.
and I'm telling you that the chance that someone wants to VC you instead of just type on this server is low
Sorry for pinging, can you share it as a screenshot? I don't know but i can't download the PDF.
here you go
Thank you so much 🙏
this was like 7 years ago, and i am 26 now. so nope, you underestimated my age back then.
oh ye where do u ask combinatorics questions again?
ite
wait help pls? 
I was think additive popery of length or midpoint for the first one.
For the second I was thinking SSS
Or side-side-side therom
wait
yeah its prob additive property of length
OK
google ai says midpoint

and SSS and be deduced because al three sides are congruent to each other
I GOT IT
$\frac{\tan \left(θ\right)}{\sec \left(θ\right)-\cos \left(θ\right)}=\sin \left(\pi \right)$
theonlygardener
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
qn6 what step i wrong the ans is tanx
send a better photo, nobody can see what's written
sorry
in 2nd step how did you go from
1-tan²A / 2tanA → 1-sin²A / 2sinA*cosA ?
you are wrong here
maybe try again
Bro the writing 💀
I don't even know where to start.
I'm genuinely so cooked.
This is supposed to be a review and I have a test on this tomorrow 💔
I would start by writing down the geometry words that you don't know the definitions of and try to understand what they mean
For example: complementary angles, angle bisector, etc.
It will be helpful to draw some examples of what each of these words mean in pictures. Then to solve the problems where you need to find measures of angles, practice understanding angle addition/subtraction as well as the algebra needed to find x in each of those.
If any of the notation is confusing as well you could write down what they mean from a youtube video or Khan Academy and practice using them.
hello quick question! i got the answer 3.134 and rounded it down to 3.1 and it said i was wrong lol. if anyone could point out what i did wrong that’d be great
You will have to use tan instead of sin because tangent results in the opposite/adjacent side lengths of the angle input. sin results in the opposite/hypotenus side lengths of the angle input, you don't know the length of the hypotenuse
Well actually nevermind lol
wait i just realized i put 9.4 instead of 9.7 😭
oh I gotcha
thank you though lol!!
do you feel comfortable setting up the trig ratios to find the side lengths?
by using sin i can
im not too sure abt tan tho cuz none of the example problems listed use it
just remember SOHCAHTOA
hey guys
Im in precalc right now, but in class we're reviewing trig/algebra 2 rn bc its the start of school and I lowkey forgot everything
review using Khan academy
ok
how is #8 negative cause i’m confused
,calc 840 - 2*360
Result:
120
it's in the second quadrant, where sin is positive and cos is negative
hey guys, i really need help bc i dont understand, so to find the distance between 2 point, we use the pythagorean theorem, but also everything is squared, so can we cancel the square by rooting everything???
square roots don't distribute over addition, so in general
[ \sqrt{a^2 + b^2} \ne \sqrt{a^2} + \sqrt{b^2} ]
cloud
no but i mean, if the equation is c² = a² + b², and we use this equation to find the distance between 2 points, cant we just root c², and since we are doing that on 1 side we have to do it on the other
you know what i mean?
well you can always use the rearranged formula
[ c = \sqrt{a^2 + b^2} ]
if that's what you mean
cloud
thats my point, why are we cancelling the square of D, but not the rest of the equation?
are you asking why we aren't doing
[ \sqrt{a^2 + b^2} = a + b? ]
cloud
no, what i mean is if to find the distance we use c²=a²+b², why do we square both sides and destroy the roots. so use this equation instead c=a+b
but that equation isn't true
like using
[ c^2 = a^2 + b^2 ]
and
[ c = a + b ]
will give you different values for $c$ (try it for some sample values and see)
cloud
the square root of a^2+b^2 is not a+b. for example a = 3 b =5 (sqrt(9+25) therefore sqrt 34, whilst 3+5 is 8 )
because if it was $c = a + b$, that implies $c^2 = a^2 + 2ab + b^2$ which is evidently not the pythagorean theorem, which says $c^2 = a^2 + b^2$
shiru
you can't unsee this
Yo @obsidian harness Are you good in linear equation in two variables?
dont post the same thing on multiple channels
can someone help me
!da2a
No need to ask “Can I ask…?” or “Does anyone know about…?”—it’s faster for everyone if you just ask your question! See https://dontasktoask.com/
if we take 100-3x=20+2x, is X= 24 or x=16???
But add 3x-20 to both sides
Ok but why isnt it -100-2x
Do that, you get -5x=-80
you could do that,
most people prefer to avoid excessive negative signs
if you're adding the same amount to both sides, it'll still be valid
and lead to the same end result
hi guys
can someone help me understand geometry
like point, line, line segment, ray, plane, colinar, coplanar, and congruent segments
Study geometry positional for a better understanding of what they are, depending what geometry are you studying, they change.
can u look at my post
im really confused about that because i thought f was in both planes
You are studying plane geometry, right?
A geometric plane is a two-dimensional location
You can see that like a function
Ok, to be in both planes it has to be in the middle of the planes
wdym
Since these planes are perpendicular, for a point to belong to both it needs to be part of the intersection of these planes.
I see two letters F, am I correct?
ED It is on both planes
so ED is the only one that involves both?
Yes
ED, EB and BD
You can track the other points as well
Yes
ok
See
thank you
can anyone help me with geometry proofs?
Can someone show me an example of a proof
what proof exactly
Direct
Rigid transformations if that’s possible
im so sorry but thats still very vague for me to show an example of proof of
what do u want exactly
Nvm
proof that c × 0 = 0 (where c is any number)
we know that 0 is the "additive identity", i.e. c + 0 = c for any c
therefore 0 + 0 = 0
therefore c × 0 = c × (0 + 0)
now distribute the c to get
c × 0 = (c × 0) + (c × 0)
now subtract (c × 0) from both sides to get
0 = c × 0
■
(the square means end of proof)
Does anyone know what I’m doing wrong? I keep getting decibel
you didnt subract 2 from RHS i think
in the second step its still 11
you always do the same operation on both sides of the equation
if you subtract 2 from LHS, you need to do the same from the RHS to keep both sides equal
yw!
Thank you!
np!
thats honestly a great analogy, saving it!
how do we prove section formula with trigo?
you don't need trigo at all....
it's 100% algebra
ah
not 4th?
oh nvm tht was a decade old msg
guys is there any good book on geometry
coordinate geometry or like triangles?
just geometry in general honestly
coordinate by sl loney is good
okokokok ill look it up thanks!!!
he asked for geo and you give him bash? Who hurt you
120 degrees is in the 2nd quadrant last i checked
is it not relevant?
mersenne jumpscare
so my teacher gave this to my class and asked us to prove it..
hooray!! :D (my brian hurts)
I need someone who can teach me trignometry in zoom
I can
😱
how?
Dash
How do you want?
By zoom
Meeting
i'd focus on expanding the right side
yo chat, i was just peeking at this and couldn't get how the coordinates (sqrt3/2,1/2) were found in 30 degree sector
like you can find the arc length and then find the coords but you should know atleast one point (x or y) or am i just losing it
and moreover how do you find pie related identities through it :/ like if you draw up a perpendicular on radius then it will something like 1 - x (where x is something which is left out by the perpendicular)
it all comes from the 30-60-90 (and the 45-45-90) triangle
take an equilateral triangle with sides 2, 2, 2
now split it in half, so the side 2 gets split into halves 1, 1
then we look at one half of the equilateral triangle only
no worries!
..
yeah then by Pythagoras we have b^2 + 1^2 = 2^2 or b = sqrt(3)
I'm not sure what you mean
i mean there are identities like cos(pie/2) etc., they came up through the unit circle right?
yes
so the unit circle definition says that cos(theta) is the x-coordinate
no worries!
ae yo bro, sorry for disturbing again but sin30 = 1/2 but if i take the ratio of sides for sin it comes out as (sqrt3)/2
the side 1 is opposite to the 30 degree angle
This question is confusing me. It says angle 4 is 48 degrees but angle 3 and angle 4 have to be 180 total and 4 is clearly a wider angle than 3?
Diagrams can be deceiving
What's more likely is they copied the general diagram and picked a random number for one of the angles
Yeah, I looked at the other questions and that’s exactly what they did 😭
Thank you
i once had a test that had one of these angles come out to 114 degrees when it was clearly an acute angle…
ref do something ?
Its so confusing when that happens 😭
i had an agle go to 200+ degrees... its j about the numbers not the angle math part
E
just covert sec and tan into sin and cos
in numerator it would be 1+sinx
=
write 1 as sin ^2 x/2 + cos ^ 2 x/2
Use half angle identity and simplify both sides (lhs into cos and rhs into tan) then show them equal (if you still haven't done it)
I think ts the ans
how to get good at math
practice
Nah I got it already dw, the teacher said he just forgot to change the diagrams 😭
Can any1 help me in like the thinking process u should have while doing trigonometry and dealing with identities, like which identify is right to apply in the question and stuff, its a bit confusing for me
same doubt for me too
hi, welcome to the mathcord! please only ping helpers once!
Oh sorry
also, how can we help you if we don't know your question 
Need help on arc length
can you post your question here?
Yes
picture on the way? 
okay! what have you tried 
He attempts to explain it but I dont understand what you do with the radians
What do I minus from 360
Is there a circumference formula
Ok
do you agree that arc AOB is (2pi/3)/2pi of the whole circumference?
Yes
okay. so that simplifies to: AOB is 1/3 of the whole circumference
do you also agree that arc ACB is [whole circumeference]-AOB?
(please let me know if you have questions by the way!)
no problem! let us know if you have any more questions 
i would personally do it by seeing ACB as 2/3 of the circle so I just multiply the circumference by 2/3
that works too!
yo im looking for a tutor for the sat im willing to pay if reasonable and you have credentials dm if interested
it could also be solved using (pirtheta)/180
Wow you are all genius
Thats jus how i write
Try to find complex solution for z
$$
sin(z) = 2
$$
TheSup_3912
if $\sin(z) = 2$, then one cosine value corresponding to $z$ is $\cos(z) = \sqrt{1 - 2^2} = 3i$. therefore one of the solutions for $z$ satisfies $e^{iz} = \sqrt3 i + 2i = i(2 + \sqrt3)$. therefore one of the solutuins is $z = \ln(i(2 + \sqrt3))/i = -i\ln(i(2 + \sqrt3))$
shiru
does anybody have resources for conics questions
oh u were doing the 840 one i was doing like te one before that
2 pi
right ?
ye it is
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
i think the cos²+sin²=1 identity would be useful here, just a lil hint
not sure if this is the ans you r looking for, but ig this could be one of the way to approach it
can you explain your answer, I dont really understand it
sure, which part
top right
i just took sinx common from sinx + sin^2 x
shi i forgor 😔
happens👍
hi, im terms of an angle and the sine/cosine/tan functions
is it correct to say that a trig function is eqivalent to the angle theta?
and vise versa?
as in its a fractinoal representation of the angle
like .5 is sin(30) degrees
there is only a 1-1 correspondence between angles and trigonometric ratios if you restrict the angles to be acute
ohhh
if I know cos^2(t) = 0 and that sen^2(t) = 1, how do I find t?
And of course sin(x)=(sqrt(5)-1)/2 from (2)
Wait guys
I forgot how to find the diameter
So I used one end point and another endpoint, using a straight line
And found the distance
Is that still considered the diameter?
(Yes I went through the middle of the circle)
any straight line passing through the center of a circle is a diameter of that circle
and its length is 'the diameter'
after getting sin^2x (1+sinx) i took sin^2x as 1-sinx (rearranging the given) which leads to 1 - sin^2 or cos^2
maybe there are multiple answers, you know in what terms you have to show the answer in?
wrench button in top right corner
I see🙏
this stupid math question that took me several hours before I gave up, I was seriously considering wrighting y=ix+i
Hi, I’m struggling on #6 and #7 can anyone help me?
,rotate
any1 can help me prove shors equation?
$V_f = (1/3) \pi h(R^{2} + r^{2} + Rr)=\frac{7}{12}\pi R^{2}h $
now simplify
Im struggling on this section
the answer is 5
For which question?
In 7th question, your answer is missing 0, 1, 10
8th is 2, 3, 5, 7
9th is nothing (∅) Clear contradiction there.
Thank you
You're welcome.
idk
Are you sure 9 is correct?
For x to be satisfied, it would have to be a prime number and and not a prime number at the same time, that's just not possible.
who can explain me this problem?
Calculate the value of k for the lines:
x + 2y - 3 = 0, x - ky + 4 = 0
so that
a) they are parallel
b) they are perpendicular
Can anyone help me with problems 6 and 7 please?
U should convert both the equation to a slope intercept form:y=mx+ c
Where m is the slope
when the triangle isnt a right triangle:
law of sines/ law of cosines :)
yeah but his code isnt made to do those
gonna be honest i rlly dont get the law of sines
Law of sines says that the ratio of any side of a triangle to the sine of the angle opposite to the chosen side is constant.
So in triangle of sides a,b,c and their corresponding opposite angles A,B,C, we have a/sinA = b/sinB = c/sinC
is bro Shakespeare
???
That’s poetry to me.
because a/sinA = b/sinB = c/sinC = diameter of circumcircle
also because because a/sinA = b/sinB = c/sinC = diameter of circumcircle
i might be wrong but i think thats for the same reason as why a/sinA = b/sinB = c/sinC = diameter of circumcircle
Is c²=a²+b²-2ab.cos(c) valid for right-triangles?
Yes - the law of cosines holds for all triangles.
Alright 👍
Humm, cosines just cancels itself in case of 90 degrees angle?
cos(90°) = 0 which leaves you with pythag
also use capital C for the angle when using lowercase c for the side
Here's a Voronoi diagram with the metric varying between Manhattan and Euclidean distance, and you can see how each boundary has at least one fixed point (spoilered because ugly lol). Does every diagram like this have fixed points?
Here's the code I used to make it. It's really unoptimized so don't be scared if the tab freezes lol
If you add ≡₁(×Weights) between lines 8 and 9, it adds random multiplicative weighting
Also, is there a way to predict how many fixed points there'll be in a given boundary?
lol
if it works, it works 💀
it will work eventually it just takes like 30s
Interesting counterexample bc I think the boundary doesn't even exist in Manhattan distance
I think all 2-region diagrams have at least one (usually at least 2) fixed points though
(change [4 2] to [2 2] in line 3 to see those)
Does anyone understand how to get better understand soh-cah-toa with angels, decimal numbers, and solving expressions with them. Im self taught so far and cant find anywhere on youtube that explain kind of what Im looking for. For example If cos(236 degrees) = -0.559, find the value of sin(236 degrees).
hi
would plane ABC work for plane W as well?
Also, with an intersection, how would I know if it's a line, ray, etc . . . if it doesn't mention anything?
No because there are points in plane ABC that are not part of the intersection
ex. B is in plane ABC
but is not in plane ADE
i dont get it
two planes either don't intersect at all or have a line as their intersection
hold on I was talking about 7 for some reason????
yes plane ABC also works for question 6
this commentary still holds
disregard the rest
yes plane ABC also works for question 6
same with DAB
yes
any selection of three (or four) letters from {A,B,C,D} works
so the intersection of ABE and ABD, AB would intersect and would be a line?
for example to the other question
yes the intersection of plane ABE and ABD is line AB
so <-->AB
ok
ty ty
line segment ----
ray --->
line <--->
oh yeah
when do I use commas?
for example is it plane A,B,C or ABC
and for mentioning points/planes/etc . . . would it be with commas?
like which 2 planes are collinear, i would put A,B
the question prob doesnt make sense
in that case you're using the comma as a grammatical object, so that's fine (assuming you used actually correct plane names)
to separate two things
just an example
so for mentioning a list i use them in geometry?
like points A,B,E are collinear
not ABE?
yes because that's the function of a comma in language in general
you should
because again you're separating the points in a list
they are not coagulating into a single entity
anyway I gtg
can someone explain C:
also why is not included in the intersection of ZVY and R
is it because its higher up than the other 4?
Think of it like this
When two lines meet their intersection is a point
Scaling up from 2D to 3D
When 2 planes meet what would their intersection be?
They said intersection which means it should lie on both the planes
Is Z in both plane R and ZVY?
im not sure
z can be apart of the planes but idk if its the same plane as R
Let's go step by step
Is Z on the plane ZVY?
yes
idk
Just check if Z lies on the plane or not
how do i do that
Well from the image you can say that Z is above the plane R
Agreed?
So that obviously means Z is not on the plane R
ok sorry
No no
I mean yes they both are not the same
I think you are having trouble imagining the planes
Think of the plane R as a sheet of cloth
And then we stick 4 small circles on this piece of cloth
These points are V W X Y
And now place a ball above this piece of cloth(plane R) with some distance between them
This ball is the point R
Yes the bottom four points are on the plane R
ok thanks
how do i know whether or not a point is on two points or one point
when they intersect (planes)
Point is on two points?
Not sure how to explain that but let's try an example
From here say
Let's say we are considering the plane ZVW
Is point X on the plane ZVW?
thats the same question
Let's get this easy for u
Every face is a plane
How do u recognise this
So
Imagine the face of triangle any one
With paper stuck from behind
So the 3 points r on the plane of paper
So we can say the face of triangle is a plane as well
This is same for all faces
So we can say point z
It is the intersection of all planes except the plane R
Which is bottom
look up adventitious triangle
@here can anyone help me
shure
can i help u
Can anybody try to prove it? I did it like a few days ago- but wasn't quite satisfied by my method of proving this result at all, because it was quite tiresome and lengthy.
Do try it.
is there a range or interval for A,B and C ?
because ifA=B=C=pi , then LHS is 1 and RHS is 3 , so they arent equal
there's a lot of videos online on this exact problem
120° ??
Relation between A B C??
Nah. It ain't like that. These are just the angles in a triangle, no other information given in the offending question
Oh mb forgot about it, these all are the angles in a triangle
My bad that I didn't inform this tidbit of info correctly
My very bad.
alr
A+B+C=π that's the only relation?
Did u try -2sin(c+d/2)sin(c-d/2) = cosC-cosD
yea
nothing else
i had used sin (a+b+c)'s identity btw @whole flame
HELP ME PLSPSLSLSLSL
grade X.
Yes.
@whole flame @proper ember did you two do it or....??
pi - A = B + C, \quad \pi - B = A + C, \quad \pi - C = A + B.
1 + 4 \sin\left(\frac{B+C}{4}\right)\sin\left(\frac{A+C}{4}\right)\sin\left(\frac{A+B}{4}\right).
Let
\frac{A}{2} = x, \quad \frac{B}{2} = y, \quad \frac{C}{2} = z,
x + y + z = \frac{\pi}{2}.
Rhs
\sin x + \sin y + \sin z.
\frac{B+C}{4} = \frac{y+z}{2}, \quad \frac{A+C}{4} = \frac{x+z}{2}, \quad \frac{A+B}{4} = \frac{x+y}{2}.
So
1 + 4 \sin!\left(\tfrac{y+z}{2}\right)\sin!\left(\tfrac{x+z}{2}\right)\sin!\left(\tfrac{x+y}{2}\right).
\frac{y+z}{2} = \frac{\pi}{4} - \frac{x}{2}, \quad
\frac{x+z}{2} = \frac{\pi}{4} - \frac{y}{2}, \quad
\frac{x+y}{2} = \frac{\pi}{4} - \frac{z}{2}.
So
LHS = 1 + 4 \sin!\Big(\frac{\pi}{4} - \tfrac{x}{2}\Big)\sin!\Big(\frac{\pi}{4} - \tfrac{y}{2}\Big)\sin!\Big(\frac{\pi}{4} - \tfrac{z}{2}\Big).
I used identity
\sin!\Big(\frac{\pi}{4} - \tfrac{t}{2}\Big) = \frac{1}{\sqrt{2}}(\cos\tfrac{t}{2} - \sin\tfrac{t}{2}).
So
\sin!\Big(\frac{\pi}{4} - \tfrac{x}{2}\Big)\sin!\Big(\frac{\pi}{4} - \tfrac{y}{2}\Big)\sin!\Big(\frac{\pi}{4} - \tfrac{z}{2}\Big) = \frac{1}{( \sqrt{2})^3} \prod_{cyc} \big(\cos\tfrac{x}{2} - \sin\tfrac{x}{2}\big)
LHS = 1 + \frac{4}{2\sqrt{2}} \prod_{cyc} \big(\cos\tfrac{x}{2} - \sin\tfrac{x}{2}\big).
LHS = 1 + \sqrt{2} \prod_{cyc} \big(\cos\tfrac{x}{2} - \sin\tfrac{x}{2}\big).
It is known that:
1 + 4 \sin!\Big(\frac{\pi}{4} - \frac{x}{2}\Big)\sin!\Big(\frac{\pi}{4} - \frac{y}{2}\Big)\sin!\Big(\frac{\pi}{4} - \frac{z}{2}\Big) = \sin x + \sin y + \sin z,
Fkkkkkkk
Brooo
I typed the whole shit
What the hell
Someone fix this
lmaooo
trying
😂
How does that bot convert text
I did all right i guess
But bot ditched me
$\sin x$
south
🤣
loll put dollar
$\pi - A = B + C, \quad \pi - B = A + C, \quad \pi - C = A + B$
$1 + 4 \sin\left(\frac{B+C}{4}\right)\sin\left(\frac{A+C}{4}\right)\sin\left(\frac{A+B}{4}\right)$
Let
\frac{A}{2} = x, \quad \frac{B}{2} = y, \quad \frac{C}{2} = z,
x + y + z = \frac{\pi}{2}.
Rhs
$\sin x + \sin y + \sin z$.
$\frac{B+C}{4} = \frac{y+z}{2}, \quad \frac{A+C}{4} = \frac{x+z}{2}, \quad \frac{A+B}{4}=
\frac{x+y}{2}$.
So
$1 + 4 \sin\left(\tfrac{y+z}{2}\right)\sin!\left(\tfrac{x+z}{2}\right)\sin!\left(\tfrac{x+y}{2}\right)$
$\frac{y+z}{2} = \frac{\pi}{4} - \frac{x}{2}, \quad $
$\frac{x+z}{2} = \frac{\pi}{4} - \frac{y}{2}, \quad $
$\frac{x+y}{2} = \frac{\pi}{4} - \frac{z}{2}$
So
$LHS = 1 + 4 \sin!\Big(\frac{\pi}{4} - \tfrac{x}{2}\Big)\sin!\Big(\frac{\pi}{4} - \tfrac{y}{2}\Big)\sin!\Big(\frac{\pi}{4} - \tfrac{z}{2}\Big)$
I used identity
$\sin!\Big(\frac{\pi}{4} - \tfrac{t}{2}\Big) = \frac{1}{\sqrt{2}}(\cos\tfrac{t}{2} - \sin\tfrac{t}{2})$
So
$\sin\Big(\frac{\pi}{4} - \tfrac{x}{2}\Big)\sin\Big(\frac{\pi}{4} - \tfrac{y}{2}\Big)\sin\Big(\frac{\pi}{4} - \tfrac{z}{2}\Big) = \frac{1}{( \sqrt{2})^3} \prod{cyc} \big(\cos\tfrac{x}{2} - \sin\tfrac{x}{2}\big)$
$LHS = 1 + \frac{4}{2\sqrt{2}} \prod{cyc} \big(\cos\tfrac{x}{2} - \sin\tfrac{x}{2}\big)$
$LHS = 1 + \sqrt{2} \prod_{cyc} \big(\cos\tfrac{x}{2} - \sin\tfrac{x}{2}\big)$
It is known that:
$1 + 4 \sin\Big(\frac{\pi}{4} - \frac{x}{2}\Big)\sin!\Big(\frac{\pi}{4} - \frac{y}$
${2}\Big)\sin\Big(\frac{\pi}{4} - \frac{z}{2}\Big) = \sin x + \sin y + \sin z$
Dhairya
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
diy then.
no
not a typo
search on the web
and you'll end up with results
I alr solved it..
x+y+z = pi/2 right ? how is it pi
pi radians is 180 degrees
ye
but x y and z are half of A B and C
they formatted it wrong lol; they did actually write pi/2
the question was based on A,B AND C being the three interior angles of a triangle.
dont mess it up.

well mb i pinged you for no reason lol
Dang
I know bro
I just tagged to ask
Bcz i am in bus
N there was this dude standing next to my seat
Peeping in my phone
BMTC, aint it?
whore ass fool
What's that
lol
Did u do the same way
it is a local means of transport in my country uk
nah entirely differently
Ahhh yeah
well first clean up the code to make it comprehendable
then how dont you know BMTC?
i didnt look into it much though
give a hint atleast what was done
We call it brt
Different names
Depends on region
Pmpl
In my region
@whole flame maybe you proved something incorrigibly wrong ig
you obtained this:
well we were meant to prove it
I assumed x as A/2
and first clean up the LaTeX coding behind it
oh ok
my method was huge and maybe, to say, a bit long
do you need it @proper ember @whole flame ?
or shall i abstain from sending it here?
Ahh go ahead
I would like seeing that identity
Of sina+b+c
i didnt derive it but used it heavily for the starting steps
Damm daamm
U were confused in beginning
Like pro tip from be
Where ever u see sin together
Use cosC-cosD
Is this the solution of ONE question?
Yeah but his approach was length
Took him time to figure out
Check my solution
Oh damn i had a heart attack lookin at that
This
..
Its still really long, for my level-
Im in 10th grade so yea :’)
Ohhh
I had this in 11th
But trigo is abt mastering
yea. it went too long tbh
nah man idts
i simplified it radically
but was too lengthy tbh
why do you think like that? i wasnt confused/anything
@whole flame can u clean up the latex a bit? i was planning to save it for further thoughts
U started of by rearranging LHS and RHS
Then again after 3 steps u went to RHS
It's clean proof if u start without changing LHS and RHS terms of question
So maybe
Bro yk what
I just tried those commands for first time
N the results were 😅
It didn't work
So i don't know exactly how to type and fix this shit yet I am a c++ coder
U can ask me if u get problem understanding any step I'll tell yaa
But sorry u will have to edit it urself
Bcz for me tbh
I solved this with reference formula for u
If i was to write this question i would have done it in 6 steps minimum
it aint so hard to tell man
i modified it too much but tbh i find it nice
a little harsh on those who dont know trigo at all but yea
idts i was confused while writing the solution to this at all, maybe confusions here and there might've occured
but that is my MO
to prove things