#geometry-and-trigonometry
1 messages · Page 101 of 1
Hello, how do you get the value of x?
Have you tried anything?
Oki
can you find this angle?
the one in red
-# (and maybe next time I should make it thicker)
65?
hmm…not exactly
Oh
we don't know that the big triangle is isosceles
in fact, it isn't
but can you use the fact that we know the two angles in the big triangle to find out this one?
Ohh so its 45
yeah!
Isosceles triangle has 45 right?
the small triangle is isosceles, yes, and so you know two of the angles already
you can use the exterior angle theorem
and you get x=?
What's that
give me a sec, pulling pic
Oki
Ahhh that one
mhm
^^ ?
So 45+45-180?
why -180?
90°
Because of the straight line thing, from what I remember its angle is 180
yeah, but here x is angle d, and angle a and angle b are both 45º
Is angle c also 45?
that isn't possible, because 45º+45º+45º=135º, and the sum of angles in a triangle is 180º
Oh
So its 180-90 = 90°
Then angle c is 90° as well?
and then 180-90=90 again, but you can just do it directly by adding the two angles
mhm
the idea of this is that the angle outside of the triangle is <a+<b
Oh that equals to angle c?
no, it equals angle d
Ahhh oki I got it, thank you so much 🫶 , I've been having a hard time with this question
which exact question are you having trouble on
one at a time pls
srry im not accustomed
IDK how to resolve second problem
is there a proof as to how $\sin{(x)}=\sin{(\pi -x)}$ or say $\cos{(x)}=\sin{\left(\frac{\pi}{2}-x\right)}$?
parabolicinsanity
i never really understood why, and just remembered to ask 
you can use the unit circle
suppose you have a point on the unit circle
what happens if you added π? where does that point go?
yeah, I get what u mean
so we know that cos is the x value, and sin is the y value
what is the relation between the new y value and the original one?
it becomes negative, i think
yeah, and so that's the proof for sin(pi+x)=-sin(x)
u can do something similar for sin(pi-x)
oh, i think i understand now
and for pi/2 as well
i just remembered, perhaps the sin(A+B) and cos(A+B) expansions could help too...
😔 i forgot about those...
anyhow, thanks 
oh, that works too 
,tex .sum diff trig
astraea 💫
i meant like before that but thanks for the refresher
welcome to the mathcord btw 
AB is the diameter
P is the midpoint of CB
O is the center of the circle
PO=8
R=9.6
ACE~OKE
is it true to say EO=3.6?
Just had my hs finals and would like to know if I was right or wrong
yes
So $sin(\theta) = 2sin(\theta)cos(\theta)$?
Iotavian
no, $\sin 2 \theta = 2 \sin \theta \cos \theta$
south
semantic gripe but it's true if you treat it as an equation rather than an identity
0 = 1 is true in the trivial ring
I don't know why $sin \theta=sin \theta cos \theta$?
Iotavian
It's not, unless the cosine is 1.
sin 2theta you mean?
No sin theta only
^
sin(2x) =/= 2sin(x)
May I have lessons on my ball cancer
use chatgpt haiyaa
!nogpt
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).
knew it
where are you seeing anybody say that sin(θ) = sin(θ) cos(θ)?
Oh
You can see this because it's possible for 2sin(x) to be 2 (such as when x=pi/2), but sin(2x) is never 2.
Oh
So ugh....Is this applied to prove the initial equation?
@static sapphire welcome to the mathcord 
which equation?
yes sir
thx shubham
as in the guy from inside
is this a current test?
or
well actually the grades are already placed on it
so whatever
share your progress or working on each one
No
use the standard tan(a-b) identity for 4th one
for 5th one take out cos(x) common and substitute 4+2sqrt(3) again and solve for x
4th
can i ask question here
sure
do you still need help with this
yes
you re given one spacing subtends 6 degrees and total spacing to be 17 and a half. You can calculate total subtended angle and then use the formula pi radians = 180 degrees to convert
ok, can you express the angle they ask for in degrees for a start?
dawg I just want the solution
this the entire question
please do not call me "bro".
and no, we will not give out solutions.
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.
!noans
The purpose of this server is to help you learn, not to hand out answers. Do not ask someone to give you the answer directly.
@fathom lynx please edit the word "bro" out of your message!
k

this server is not a "do your homework/questions/whatever for you" server
then wut is it
but basically you're expected to put in some effort
my suggestion in particular was meant as an intermediate step to doing the question
and so it is with literally any question posted on here
I should start reading these when joing agroup
i mean yeah you should
you should always read the rules when joining any server
that is... what rules are for
yes
sorry abt
i just call everyone bro for being friendly
right, some people don't like being called such words though.
so you gotta remember that. and if someone asks you not to call them by some word, you respect it. basic decency.
(and you did that)
btw dont read my status
this shi made me laugh
wat
well I am glad someone found it funny
I almost got banned for having that bio in a different group (r/undertale/deltarune)
The sin 2theta = 2sin theta cos theta
man I didn't know this server existed. Time to share knowledge
anyone know why I cant look into members old msg
into any member's old msgs or just a specific one?
cuz if its specific maybe cuz they never typed
here
wait do yall know if for summer courses the high school is gonna give u a placement test to see if ur ready for the next course (example: if we’re already done with biology, will the high school give u a test before allowing u to move on to chemistry??)
also for math (if we’re not doing a summer course on math), will our high school test us on algebra and geometry before allowing us to progress onto the “advanced” algebra 2/trig course?
just wanted to ask cuz im going to a public hs this eyar
uh, that's not the function of a placement test
usually you just need to pass/achieve a certain grade in the previous course to take the next course
I don't know your school specifically
but placement tests are for if you want to take a course earlier than your school's timetable, so you have to demonstrate knowledge of the prerequisite course material for that class
dm me i need help on trig
why not just ask here?
idk
need help with memeorising the identity for mulas except for the pythagreas one
okay, so if we start from sin^2 x + cos^2 x = 1
what happens if you divide everything by cos^2 x?
is actually a consequence
try sin(a + a)
thanks so much for replying so quickly!!
just wanted to follow up with another qs: how does the high school evaluate a summer course (as u mentioned, I am completing a course before the actual timetable suggests - biology), and I already took alg 1 and geometry in 7th and 8th grade respectively. What im asking is if they will give me another placement test for biology (to see if im ready to move on to chem) and geometry to see if im ready for advanced algebra 2
mm they'll usually correspond with your middle school, say ask your teacher about how well you were doing in those classes besides your grades
but yes they could equally give you a placement test covering material from those classes if they can't be bothered to do that
your best bet is to ask your high school directly
ohh ok
just email them and they'll answer
it's great you're thinking about how to manage your educational options and make the most of your time in school though!
when I was your age I certainly wasn't as proactive
also schools give some very clichéd advice about subject options, like "don't pick a subject just cause your friends are also doing it"
they're treating you like babies when they say stuff like that
there are definitely going to be people with the same maturity that deserve much better advice
cause it's not just about "what are you going to do after high school? are you going to college and what are you going to be studying?" either
Yes indeed
thank u lol
i prob have forgotten everything in geo over the summer lol
so i have to study
very true
if I could say one thing, it'd be don't be afraid! you're going to have a lot of choices but that doesn't mean you have to get everything perfect right here, right now
oh that means a lot! Thank you!
yeah honestly I hope you can just get through everything
I experienced a lot of injustice as a teenager that I didn't quite have the words at the time
so being in your early 20s can be a new start
ohh i see; well, i hope ur new start is gonna be/is perfect!
it sounds like you could do a lot of good things in the world
but equally don't be surprised if life just kind of rolls you over either
thank you!
yup that's true
Thank you!
fml I should have just said why
actually the problem was with my account, but it got fixed by simply reloging
I thounght it was a new discord update where ppl cant look in older msg for privacy but it simply a glich or smth
right, you need to check the case where $\tan^2 x \tan^2 3x - 1 = 0$
south
otherwise you're dividing by 0 and that step is not valid
dividing is fine: you don't always need to factor it to avoid dividing
you just need to check when it equals 0
Good morning, everyone. Uh, sorry to interrupt, but do you have any tips for getting started with trigonometry and geometry?
have you tried looking through Khan Academy?
No
go do that and come back
there's videos and quizzes
I say that cause it's hard to help if you don't post a specific question/exercise
so I've just referred you to a place where you can both learn and practice
oh right mb but then the solution becomes too long cuz write general formula and take intersection or am I dumb idk
in fact no, cause by subbing in you get $0 = \tan^2 x - \tan^2 3x$ or $\tan^2 x = \tan^2 3x$
but $\tan^2 x \tan^2 3x = 1$ so $\tan^2 x = \tan^2 3x = 1$
the intersection of both equalities is hence $\tan^2 x = 1$
south
it's a coincidence that tan^2 x = 1 doesn't introduce any new solutions
you're actually not missing solutions
ty
so uh I'm learning abt trig using this YouTube video and I don't know why but I entered the same problem in the YouTube video in this calculator and the YouTube video got different answers than my calc so idk why someone help please
Hiii guys, I'm new to this server, and for math too :P, if anyone wanna study with me, I will be really grateful. I'm currently studying deeply sines, cosines, tangents, all their inverse functions and inverse values
You calculated the cot of 5/4, which is equal to (tan(5/4))⁻¹, that has nothing to do with the atan of 5/4, which is tan⁻¹(5/4)
you should press inv+tan buttons to get arctan
Y=(X+Z-1)!/(X-1)!Z! {X≥0} {Y≥0} {Z≥0} (Integers only). This is Pascal's triangle, X is the dimension, Z is the term, Y is the output
geometry indeed
by dimension I am referring to the dimension of the triangular sequence, like 2d is n(n+1)/2 (triangular number sequence) 3d is n(n+1)(n+2)/6 (tetrahedral numbers) ect
Well it is graphing
uhh no, law of cosines is different I think
i beleive it is used in triangles
In geometry, Descartes' theorem states that for every four kissing, or mutually tangent circles, the radii of the circles satisfy a certain quadratic equation. By solving this equation, one can construct a fourth circle tangent to three given, mutually tangent circles. The theorem is named after René Descartes, who stated it in 1643.
Frederick ...
aight thanks
(there has to be a Wikipedia version of JFGI...)
Hi
Oh yeah lol i mixed up Carnot with Descartes 🙈
IGNORE this, my bad @regal kraken
aight
its right
it was actualy
tan^-1
not tan(5/4)^-1
\documentclass{}
\usepackage{}
\begin{document}
Given:
[
\tan(\theta) = \frac{\text{opp}}{\text{adj}} = \frac{5}{4}
]
The angle (\theta) is:
[
\theta = \tan^{-1}\left(\frac{5}{4}\right)
]
Calculating:
[
\theta \approx 51.34^\circ \quad \text{(or } 0.896 \text{ radians)}
]
\boxed{\theta \approx 51.34^\circ}
\end{document}
ponkur
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
is there any other way except cauchy inequality to find the range of this function?
,rccw
It doesn't make much sense to say "for all x, find the range of the function". The range of the function is what it is; it doesn't depend on x.
it's an abuse of notation
they definitely mean "find the range of f: R -> R given by ..."
yeah it's an imprecise statement but widely found in textbooks ig to specify that the domain is R in a simpler way idk
anyways my sir said there is another good solution but i don't seem to find it
Hey all!
I'm looking for 3 teammates for HMMT (November & February)!
I’ll be focusing on algebra, so I’m looking for others who are strong in:
- Geometry
- Number Theory
- Combinatorics
looking for extremely skilled individuals with serious dedication!
what is HMMT?
it is a maths competition that Harvard & MIT host
it is for high school students
I'll participate but looking for teammates
great!
you can DM me if you want to join the team
I'll give u 3 questions & if you answer well, we can work with each other!
Are none of these right?
how are you reaching that conclusion?
Oml I got the answer -2+sqrt3 and I glanced to quickly over sqrt3-2
Im just lowk stupid
how can prop 3 be used to say BD is equal to AC if the only place that you can use prop 3 to do the cut is from vertex A? also im i supposed to assume that constructing DC doesnt change the angle at vertex C?
constructing DC chops the angle at C into two smaller angles visually but you dont care about it
im not sure what your objection to prop 3 is. can you show how euclid states it?
the only way to chop the less from the greater would be at vertex A on prop 6 and yeah i would think it would split the angles thats why am asking if you assume the vertex C angle stays the same
wait
do you claim that such a cut is ONLY legal if the two lines you're talking about already share a vertex
y/n
yeah i am
i cant for the life of me figure out how to do that
even in this prop 3, "Draw red = blue" already assumes you can copy segments by length
which is proposition 2
and, if you really want to spell out the construction in full,
yes
it's allowed to place the red segment on EITHER end of the white line.
no privilege is given to one end of it over the other.
do you want the dumb/non-proofy explanation
sure
if you have a 10cm rod and you want to cut 7cm off of it, you can cut off that length from either end of the rod. by your logic there could be a situation where one end of the rod is privileged over the other, and only it can have 7cm cut off from it, while from the other it's somehow like cosmically or divinely forbidden to do the same
so it just makes no sense that you'd somehow be able to cut a given length off from one end only
capisce?
how could you know you wanted 7cm cut off a line if you have no way to measure the 7cm unless you transfer a length, collapsing the compass
in this picture, you could, if you wanted to, follow the construction of prop 3 and draw a circle centered at B with radius AC.
do you agree or disagree?
no you cant without collapsing the compass, unless it was an equilateral triangle then you could
??
you are measuring the length of AC with the compass then picking it up and setting it on B
yes? is that forbidden?
The compass is assumed to have no maximum or minimum radius, and is assumed to "collapse" when lifted from the page, so it may not be directly used to transfer distances. (This is an unimportant restriction since, using a multi-step procedure, a distance can be transferred even with a collapsing compass; see compass equivalence theorem.[...])
so says wikipedia
better than ai
.....
did i stutter
can you show prop 2? @valid zinc
that one seems to be the one to do w/ transferring lengths
even when our compass is collapsing
oh
fucking hell
i pressed up arrow and pinged the wrong person
where u get yr pfp from
this is off-topic. if you want to ask me off-topic questions, then go to #chill or #discussion or #serious-discussion.
this might be hard to follow its old
you can use a newer translation if you want
ok, so you agree that transferring lengths is still possible even when the compass is a collapsing one?
or do you want this spelled out every single time in every single proposition with every single circle drawn every single time on every single diagram
thats how i want it but i can agree that you can transfer lengths without picking up the compass i just dont see how to do it on prop 6
you want to spell out the full details of the construction within the setting of prop. 6?
yes please \
hm
ok i admit even i can't quite follow this diagram for prop 2.
not sure what the "describe [triangle] (prop 1)" means
maybe you will have to show me prop 1 too
can i dm you?
no
prop 1 is just an equilateral triangle
then y do u have yr dms open?
more modern translation of prop 2
honest to god it is none of your god damn business.
also maybe you should remove the transphobic joke frrom your status.
remove jokes????
yknow what im gonna take that to #discussion my bad
dont look at jokes you dont like nut job, you would say some weird shit like that in the middle of a math conversation
ok, if i'm a nutjob then i'll just leave this convo outright, bye
bye
i am not a "mr".
and no, i don't have euclid's propositions memorized by number.
if you could correct the honorific, that'd be nice.
they've been banned for DMing another user with homophobia
lmaooooooo
who was it
eudoxus
no i mean who is the other user
doesn't matter
ok
who reported
we do not discuss moderation details with uninvolved users.
Are you an alt of the banned user
I'm aware. that doesn't preclude the possibility
I joined to seek advice
am just a curious little guy
Please keep this channel on topic
mb
yo
is that the BYU class?
huh
no just middle school algebra
i can do this in eighth grade so i dont have to do this in high school
How do i solve these types of questions
If i see its solution its gomma be so obvious
But i cant solve it
i got it
nvm
Is it possible to find the length of the sides with the given information?
In the image there is a Rectangle ABCD whose area is 36 and the diagonal line BC length is 5
I've tried an equation of systems like
Let the sides be a and b
ab = 36
a² + b² = 5
But i don't think this is the way 😭
This is what gemini says
Could I try and help?
This starts by referencing pre-algebra with area formulas, it seems
hey bro
AI for math?
Isn't ai specifically mentioned against in the rules-
Sure
oh
You have the length of the hypotenuse and twice the area of one triangle
So the question now is whether you have enough information to figure out one side
Indeed
It's too large of an area to be a 3-4-5 triangle
A right triangle with hypotenuse 5 not necessarily is a 3-4-5 triangle
I just thought it'd be better to check real quick just in case
Are there any other method options you've crossed out?
If we use a system of equations, we have:
ab = 36
a² + b² = 25
a = 36/b
b² + (36²/b²) = 25
b² = (-1296 + 25b²)/b²
b =sqrt (1296+25b²)/b
No, this system seems not solvable
Hmmm
Wait a minute
?
b = sqrt(25 - a²)
asqrt(25-a²) = 25
a²(-a² + 25) = 625
-a⁴ + 25a² = 625
-a⁴ + 25a² - 625
yeah
yeah, and on a graph the two lines don't collide
yeah, I agree there
The question asks: given the cylinder of radius r inscribed in the circle of radius 5, find the largest value of x such that its volume = 72π.
What I've tried is to find a relation to the information given.
The formula for the volume of a cylinder is hπr², where h is the height. We have that h = 2x. We want to find a value x such that 2xπr² = 72π. With some manipulation, we have:
xr² = 36
Maybe I'm overcomplicating this 
Give me a moment to follow your thought process...
Okay, I see where you're going. I'm assuming there's a second equation we're making a system out of
Stop reading my mind

If they would only give me some other angle for that triangle 😭
Hmhmh
Hmmhmgm
What's it?
x, r, and 5
Yes
What equation loves having all 3 parts of a right triangle, at least as variables
I've thought about x² + r² = 5 and guessing values for x, but I don't want to guess
Don't forget that c is squared too
Yea
So you have two equations now, right?
xr² = 36
x² + r² = 25
r² = 25 - x²
x(-x² + 25) = 36
-x³ + 25x - 36 = 0
and now we just gotta solve that!

That graph strongly suggests there's an integer root ...
(Which you were probably expected to use the rational root theorem to find).
Yes, it seems that way
I might be further out of my lane here than I realized, so I'll just hope someone else comes to help with the next question
Is there a faster way to solve this?
I usually use graphing to solve two-variable systems of equations
desmos graphing calculator is my best friend
I can't use a calculator in an actual test though
oh. That's annoying.
Most tests I get have desmos built-in
You can't even use physical calculators?
No
rip
Thats strange
Even the simplest one? Thats bad
no
it is a test where I have to solve each of 90 questions in less than 3 minutes
hmm
Guys i want to know more about
Astc rule
I don't think so.
I suppose you could have metagamed it and said, if the solution is nice perhaps everything will turn out to be integers, so let's see what happens if the x/r/5 triangle is actually a 3-4-5 or a 4-3-5 triangle.
But that feels like it depends a lot on hindsight.
Bro, that's the vertex. You can clearly see 4 getting intersected by the line.
So, that's the ez way x = 4.
zawg i'm just using differentiation for ts
We know that 2m, m²-1, m²+1 are pythagoream triplets. And the equation xr² = 36 suggests that x is a perfect square.
🙏🏼
Then, when I try to keep the known pythagorean number (5) in all the 3 expressions, we can see this:
m²+1=5
m²=5-1
m²=4
m=2
Then, 2m = 2*2=4
m²-1= 2²-1 = 3
Then 3, 4, 5 are the pythagoran triplet
put x = 4 and r = 3, then:
r² = 9
9 = 36/4
9 = 9
Hence, x = 4
👍
if you have something to ask then ask it; otherwise the answer will be "no, this server has been deserted for many years now"
:/
I see
I've test tmrw of trigonometry
I gotta do 9 exercise
[ I missed the theory classes of this chapter due to health issues]
So I'm kinda cooked rn
I mean what could be the best way to study if you are in that situation
[Pls don't be like js study]
review SOH-CAH-TOA and/or trig identities as applicable
if you're gonna get tested on the sine law and/or cosine law, review that too
know your basic trig values (0, 30, 45, 60, 90°)
these are the most important things to know
thankyou so much ive already reviewed it at all
Actually i sometimes sucks at math
how should i approach the questions of my book
Like the exercise
all of us do
what questions is it asking
Demonstrate understanding of trigonometric functions synthetically, graphically, and analytically.
Compute and manipulate trigonometric expressions confidently.
Apply knowledge of angles, quadrants, and signs to solve for unknowns.
Represent trigonometric functions visually.
Use trigonometry in context, especially with respect to measurements and problem scenarios.
summary of Half of the exercise
- learn how to graph trigonometric functions, 2. learn your trigonometric identities, 3. learn the unit circle and connect it to 1., 4. is just 1. and 3., 5. apply your knowledge
- will usually include proof of trigonometric identities using given trigonometric identities
such as pythagoras', reciprocals, sum, product, double-angle and half-angle
- will usually include solving trigonometric equations, how to convert radians to degrees and vice versa and what an angle is in terms of radians according to the unit circle
Damn thankyou so much for all of it
Should i consider watching lectures?
Any yt channel or something you would like to include
i learned via the organic chemistry tutor
but you also need to do more challenging exercises outside of the ones he includes in his videos
because they are "introductory" and aren't the full scope of the exercises you will encounter
Not the person but I really like this community college professor: math with professor V. She goes into detail and i like how she teaches https://youtube.com/@mathwithprofessorv?si=M-K9NEQrREhe4hf9. She has pretty much everything on a playlist including trig so you can see what you’re struggling with and there will be in depth explanations and a lot of examples.
Welcome to Math with Professor V! Here you'll find a variety of content designed to help you understand math topics ranging from Algebra through Calculus 3, Linear Algebra, and Differential Equations. The videos are specific and organized by course and topic to make browsing as easy as possible.
Feel free to leave video requests in the comments...
geometry, just like all other fields of math, is morally neutral
also there's the view that mathematics exists independently of our culture and society
so you can't really apply the labels 'bad' and 'good' to something that doesn't come from this world
Except for the fact that most people hate euclidian geometry
I don't think so.
Perhaps Americans who (though a tradition for misleading schooling) have gotten the impression that Eucliean geometry inherently means two-column proofs and a ban on intuition.
Truth
Geometry is a simple topic yet when taught rigidly to an early student, becomes very unappealing
I'm trying to learn the intuitive part but for me it's being harder than the rigid/proof based one 
I mean, #info message kinda states that the whole purpose of this server is to encourage learning
[that said, I do find it funny that the THINK poster's been sent three times in just over an hour
]
yo we're joking
😭
jokes aside avoid saying stuff like that in a channel like this, it may deter other learners if they see that someone has breezed through a topic they have a hard time understanding
you can get a decent structure from khan
algebra,
definition of perimeter/area and the respective formulae for common shapes
parallel line theorems
alr
coordinate geometry / basic graphing
Whats a free website that'll solve math all free
Thankyou so much
I really needed this tysm 🙏🏻
Alright
Ty
Guys need help with graphing sine and cosine functions rn 😇🙏
I don't understand a thing from my book
please provide the question
like you want to make the graph? or want to see the graph?
Naur
It's more of a discussion thing because I don't understand anything from the book
See the graph
Wait
Idk
does the book explain using a unit circle or general function?
Idk
Waot
Wait
1 and -1
Highest and lowest so like
90 and 270 that's what it wants me to remember
Anyway I'll send the pages
Y'all pls explain each pages cuz like
Also be wary of the terms.. I'm unfamiliar
Wait rlly?
seems like a unit circle
same thing
access denied
.
usually I would explain a sine or cosine using a unit-circle with the 90° triangle like this: https://www.geogebra.org/resource/uvJq3wEm/LQpXDRXhqPeAvJC2/material-uvJq3wEm-thumb@l.png then move the point around on the circle and measure the length of sine and cosine. This is where you get the values from for the function graph...
I've requested access
same
Okay done
Hereee
Y'all dm me the explanation
So it wouldn't get lost
🩵
Per page
dude this book is wierd
.

same i think
i dont remember though
we start with the unit circle and then move on to physics... did you understand the unit circle @patent dirge and the other essentials mentioned on page 1?
Yesss
Ik the unit circle
Sine and cosine functions at that.
the rest is easy then
But I'm here at graphing which I don't understand
😭
and I'm supposed to answer something
And I can't answer unless I understand the book
PLS
like page 5?
do you understand the definition of amplitide, domain/range, period, vertical and horizontal phase shift?
Do you have a teacher?
for range use this formula ig
range is easy
ye
WAIT SOMEONE DMED ME I IGNORED IT ACCIDENTALLY
Whoeger u are pls dm again
U have a dog pfp
What
No
That's the thing
It's new to me
Help
I haven't read the book yet
you need to learn functions in general first
if you understand transformations it should make sense why
the range of sin(anything) is y in [-1, 1]
multiply that range by a, when a > 0 and you get [-a, a]
and then add k to both, so [k - a, k + a]
or try Khan Academy first
basically, get this basics right first
range is basically all the values the function can have
ok, maybe a more visual approach helps... amplitude=how much difference between maximum and minimum divided by 2, period: how long before the function repeats itself, phase shift: how is the function graph moved up/down or left/right compared to the sine you know from the unit circle
yeah the best thing is some textbook/book to go through the material properly
and domain is all the values x(in this case theta) can have
YouTube, for instance org chem tutor, isn't a bad source
Omg..
Tried na
This one I tried
oh because this question is asking you about how to identify the amplitude, domain/range, period, vertical and horizontal phase shift?
It's kinda ironic
yeah the question isn't asking you about how to graph trig functions
Ik how the unit circle works and cosine functions applying to unit circle
YET
I don't know how to graph
Oml
you dont need to make the graph for the questions
Yes
For instance
This looks positive
But because of the shift
It's negative
Like what
😭
what is your book using as the reference/default function?
sin or cos?
@patent dirge check your DM
are you, by any chance indian?
Idk Haven read
since we add na at the end of responses a lot
um, the answer to my question can't be both
either your book starts the transformation from sin(x)
Idk
or it starts the transformation from cos(x)
and the file doesn't have this information
sigh...
@patent dirge
.
thats why i asked
I'd say it's decent, yes
wait, do you understand that if I start with y = x^2
then I do y = (x - 5)^2
the new graph is translated 5 units right and not 5 units left?
instead of trying to follow the whole function, follow the vertex
so the vertex of y = x^2 is (0, 0), do you agree?
it seems like you haven't learned transformations of graphs right
This is an independent learning thing
Because of the weather issues, classes are cancelled right.. and we are tasked just to read the book and answer the supplementary learning
That's the thing.. without a teacher I'm flopping
And the independent task is due tomorrow
Can I send videos here
Okay I'll send what I understand and giv me feedback
ExcUSE my native language
I'm also like sending these to my friends
do you understand the explanations here? https://www.youtube.com/watch?v=EIS-tWnVWAo
Visit http://ilectureonline.com for more math and science lectures!
In this video I will take a closer look at the general form of the sine and cosine functions.
ok, so you did unterstand amplitude and period. Now you have to look at the function f(theta)=1+cos(pi\cdot theta). If you move this around you get f(theta) = 1*cos(pi\cdot(theta-0))+1 which is the same form ad y=Asin(k\cdot (theta-b))+c
I'm rewatching organic chem rn
I'll watch that after
Will ur video help me with that?
Yes ik the explanations from the picture
C is the horizontal phase shift
And d is the vertical shift right
So for horizontal ofc left and right
For vertical up and down
The shift is like the central line
This part is really complicated
Oh nvm
lol got it now
Can anyone help me quickly with a sinusoidal question? I just need the answer also it’s a word problem
!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/
I made a simplified proof to solve for the identity sin(beta-alpha) or any other sine subtraction equation. It only uses some basic geometry like congruence, some geometry around isosceles triangles, the d(P,r) formula, sine law, the unit circle.... Basically anything you would see up until your 10th year of school (excluding complex numbers).
its a nice proof 👍
do you know how to prove it using vectors? it become extra-simplified when you use them

i love geometry so much
i got 8/20 in my math test just cuz of not being able to do geometry
geometry 😈
anyone got any advice to get better at trigonometry
sorry if it's a dumb question
I know this might not be alot you should master the basics Soh-Cah-Toa
then id suggest to learn the values for sin, cos, tan at 0⁰ to 90⁰ master it by using the unit circle
And just practice some simple problems and remember you should always try to learn not memorize 
oh man where do i even start
do you know your trig identities?
yeah
do you know any ones to do with cos(A ± B)
do i want to start with given one or the tan one
ko i try
you always start with the given
i have the answer
well you might wanna expand sin(A-B)
that should give you some ideas for how to proceed e.g. how to get your hands on sin(A)cos(B)
yeah and i got lost immediately right after
i dont recall anything that changes multiplication to addition
ok well your goal is sin(A)cos(B) - cos(A)sin(B) yes?
ye
so let's set that aside for a moment
now here is a crazy idea that's actually going to cook:
take the equation sin(A) + cos(B) = m
and square both sides.
did you manage to proceed?
i have a different method
what if you multiply m and n?
yeah
you'll get a messy expression
youd have the terms you need plus some extra
u get one part thay can be written as sin(A-B)
and some extra terms u really dont want to see
ig yea cosacosb and sinasinb
also not a good approach since its just too random
oki
yeah?

going to ask a silly question
but do i need to know my geomatry well before learning trig properly
yes and no
know all your geometry relating to triangles well, because the focus of trig is how triangles relate to the unit circle
so definitely revise the special triangles, the 30-60-90 and 45-45-90 ones
but a lot of the 'proof', like two-column proofs, is totally unnecessary for trig
oh awesome ok
sweet
so which subject teaches the principles of angles
i assume trig
also observing similar right triangles is super useful in trig
geometry, actually
so all of that angles in parallel lines material belongs in geometry
it does help in trig but there's no shame in looking it up if you've forgotten
maths does tend to build on itself like stacking up a brick wall
but those concepts aren't the main focuses of trig
perfection thank you so much
the main reasons i want to know is because of linear algebra
where certrain transoformations require angles and im shit at angles
well if you're talking about linear algebra
it's not about angles specifically! it's about transformations that rotate and stretch the plane (while fixing the origin)
for those rotational transformations yes trig is very important
but it doesn't relate to angles in this context
so honestly just leave geometry behind if you're ready
ohhhh so the sin60 and all that
I think that the book Linear Algebra Done Right by Axler also has a foundations chapter at the very beginning
thats not geomatry
that's trig
oh sick!
it is a part of geometry yes but taught separately
then is there really anything i need from geomatry or can i just focus trig?
just focus trig I'd say
perfect thank you south 
if you're really missing anything don't be afraid to look back and revise if you need it
but that's on a "if you need it to understand trig" basis
of course
I did that with algebra
np!
went all the way back to 4th grade for that one
and now i understand equations, kinda haha
For the sine identity I haven’t learned anything that really comes to mind as sufficient enough to prove it, I figure you’re talking about matrices and matrix multiplication or something else of the linear algebra field. I made this proof based only on my current knowledge of mathematics up until the 10th year (here it is 4th year of high school Belgium, mostly ages 15-16). I will be teaching myself some new stuff this summer.
Where is a good place to get a really complete understanding of trignonometey before starting calculus?
I checked the pins but I dont see much
Hmm
So when I learned Trig, I didn’t really learned it in school so I have no textbook
I bought algebra and trigonometry by sullivan but I think the book is too slow paced for me as I learned a decent bit of trig and algebra from hs
But I used Professor Dave’s Playlist and an app that has Trig on it
I would also want to get a better understanding of algebra
Don’t use the app
But im decent at algebra, I just want to learn trig better
Before I start learning calc
Yeah I would just use Professor Dave’s math playlist
No prob, and just in case he doesn’t have precalc to my Knowles
Good question! Give me a sec.
Would be cool if there was a site with practice problems for all branches of math
Thats okay!
I just don’t know the name
Thank you for the advice regardless
You’re welcome
there is a nice one though, the art of problem solving i think
This is a series of books
huh?
there is a website and a trainer on there
alcumus
i used it quite a bit and it’s pretty nice
Ohhh I see
not sure if this is the right place to ask for this so please correct me if this is wrong. But is there a way to get desmos to give me this number as the fraction pi/2?
great
I don't think so.
yikes
why can it convert some decimals to fractions and not others though
but then I add 1 more digit
and it wont work
Because pi is definitionally not rational
So it can't be written as a fraction
Further, it has a memory limit
but it can be written in ways like (2pi/4)
Again, PI is not rational
So neither is any fraction a*pi/b where a and b are integers
so desmos just isnt good enough to convert it?
because can't like AI calculators do it
All AIs are merely interpolative
interpolative?
And further, MLM AIs are just interpolative of written works
As in, they take in shitloads of written works as a corpus of information, then respond to a prompt in a manner that mimics the corpus
So if the corpus contains shitloads of "sin pi = 0", then when you ask it to evaluate sin pi, it will give you 0
would still be so nice if calculators could do it
This is the crux of using AI here
Also - you gotta remember this - humans built the calculator
It's no divine entity
This is why maths is still a school subject after thousands of years
sure feels like it sometimes
That's why it's important to learn how the calculator does it, to demystify it at least a little.
Unfortunately, understanding how calculators handle trig functions (in the sense of "how can we be sure the results it gives are right") takes a lot more mathematics than it does to learn to use trigonometry for ... um ... "practical" tasks.
Hey Here is simple task May you solve the problem. That's easy
It takes for two minutes.
a + b = a * b ===>>>> a != b ~~a ,b ??
!topic and also please don't post the same question in two different channels
Please read the channel description before posting, and stay on topic.
geometry is so tuff
anyways is this a good idea?
my 7 y/o brother cant hop off roblox
i set his time limit as fibonacci sequence
i told him its the first few terms of the fibonacci sequence (there is no way he is able to spell it out in the next 2 years)
i wrote down the formula for it
if he figures it out by the end of this month he can play whenever he wants
if he doesnt im changing the psw
!topic — this probably belongs in #discussion or #math-discussion
Please read the channel description before posting, and stay on topic.
did you mean LLM
does LLM mean Large Language Model?
if it does, could there be a Medium Language Model and that's what MLM stands for?
the closest relevant acronym i can find online is Masked Language Model
yes
hi can anyone help me prove this identity
what's your progress so far?
oh someone helped me solve it already in the help section but thanks
ok then don't multipost
sorry 😭
IF U DONT MIND CAN I GIVE TELL U MY APPROACH
Why is the altitude of 30*40/50?
Try proving that triangle ABD and triangle BDH r similar
That's how they got what they got
Np
<@&286206848099549185>
!1c
Please stick to your channel.
what web is this?
Hi, not asking help for any specific question but more so on like how I'd study this topic, if I needed to learn the unit circle what's the best way to tackle it? I've always struggled with it
To solve like questions like these or anything that needs trig
start with learning how to derive the ratios for the special angles
that pretty much gives the first quadrant of the unit circle
you can get the rest of the unit circle from reflections
which also gives you the supplementary and odd/even identities
(also learn the conversion between radians and degrees)
I literally replayed ts for a whole hour and then had it memorized😭
Lowkey a banger
Or you could use the finger trick (if you have 6 your fucked😭 /j)
Crazy Hand Trick to Find Exact Trigonometric Values | Vedic Math Trick | Square any 2 digit number in 3 seconds I Square Root in 3 seconds | Math Olympiad | Harvard University Entrance Exam Interview | This question frightened 300K+ examinees! | Hard Geometry Exam Question | Only 1% of Students Got this Math Question Correct
Like what Rauomenganato said as long as you know the first quadrant then you can figure out the rest

honestly just learning your special triangles and how sin and cos actually work is way easier than memorizing these values
youre just making more work for yourself and not understanding the material as well in the process
oh that is what you're saying, nvm
Is this channel for general discussion of geometry? I’m new
yes
the fuck is wrong with yall
i just memorized it
by hard practice
will skill you up
it was good tho
Grinding through my precalc book
oh no americans
😔
im israeli.
our edu system is at the rubble
I don’t like being American😢
yo theres such a short method just divide by cos and u get cosx/(1+sinx) and then rationalise and its done in 3 lines lol
just memorize.
i remember 30 and 60 together.
Book name please?
why memorize a identity that doesn't even come many times
it does.
ik like 100 diff identities but the useful ones smh
proceed mathing.
either memorize by experience if you have good memory
or just do the hand trick or whatever trick if you struggle to remember
You can find a free one by openstax but I am currently learning from this one. I like it a lot lots of practice problems
Cool thank you
oh yeah? bro this is a garbage identity what you on😭
Do whatever helps you🤔
When did you guys start studying mathematics?
everyones accepted dw.
last year
Cool
im now doing a degree lmao
In maths?
mhm.
Sounds cool
When my 7th grade teacher was absolutely terrible at teaching (I barely passed my state exam😭 and many of her students failed and most of them were hard working) I hated math but my algebra 1 teacher the next year made me love it a lot cuz she teached well and I guess now few months later I’m learning something what I hate now I love😂