#geometry-and-trigonometry
1 messages · Page 28 of 1
Wdym
growth factor is 4 so you multiply y by 4 as x increases by 1
I need formula
Idk my prof
it’s a function you can put any value for x inside of it
since there is no initial amount start graphing at 0,0
Is this correct?
yes
The graph?
yeah graph is good
umm.. thanks
You have all the school theorems that apply
2e, 0 after first reflection
2e, -6 after second reflection
final answer is 2e, -6
I found a solution based on two assumptions:
a) Right-Angled Triangle
b) Isosceles triangle
Please see traingle on right side.
Wait is this for me or another individual?
Anyone who can check my logic.
Interesting.
I understand that angle ABC is not bisected (that is it is not split into two equal parts) based on the fact that the length of line AC is 2 + 3 = 5 Units and 2 ≠ 3 and 2<3)
Based on the iscoseles assumption, length AB = length BC
Finally, I assume that a square is formed within the triangle.
I did all the mathematics guys...
Please note: I assumed an iscosceles triangle. (I graphically estimated the values of 2cos45 and 3sin45 respectively, but ended up using a calculator for simplicity).
Can you guys help me with this question
- If Robert has a gyatt at a 45 degree acute angle, what is the length measures?
QUESTION:
Using special triangle:
cos45 = 1/√2
Does anyone know a method to calculate 2cos45 or 10 cos45 by hand (i.e without calculator) ?
(I am simply increasing the amplitude of the graph)
so you mean that you have $\cos{45^{\circ}}=\frac{1}{\sqrt{2}}$ and you need to calculate $2\cos{45^{\circ}}$?
!Yajat!
Yes. Can I do that without a calculator?
I though you asking to prove why cos(45) is root 2 over 2
,, \cos{45^{\circ}}=\frac{1}{\sqrt{2}}\[em] 2\times \cos{45^{\circ}}=\frac{2}{\sqrt{2}}
!Yajat!
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
@grand scaffold just multiply by 2 both side?
sorry for late reply tysm
A little late...
Hello @everyone! I am new to the server, so please show me the ropes!
do you know what the points are in this given graph?
wdym like the figure points?
ye
(-2,2), (-1,4), (-1,9), (-6,9), (-7,7)
it asking you to reflect them
yeh over that line
switch numbers
wdym switch numbers?
you given the points you have to switch them
for example, your point gives as (-2,2) what happens if you switch them?
2,-2?
!nosols
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.
hol up i dont think thats gonna be right

look up for Reflecting shapes article on Khan Academy
bro u do know that those are set lines
basically reflecting over the x axis and y axis
I know right?
those are specific lines that are not "daigonals"
perfect squares
the question doesnt have daigonals
diagonals*
when u do diagonal trick it does work
(F(x) = 2^x)
Janno
can u send your sol? or is there a description givne for it? im just curious
can someone help me with this - surface area of this:
Someone's been doing geometry on lord of the rings map
can anybody please help me with this problem?
😭
I need help, plzz solve with steps
x and y should be of the same sign and x/y should be greater than 1
im in honors geometry in eighth grade (bad decision on my part to take that class) and i dont understand angle relationships, like with the correspondant angles and that stuff
Why don’t they do this for a midpoint symbol, I hate writing b is the midpoint of ac over and over
The tangent lines that intersect f and g at f(x) and g(x) are parallel lines. f'(x) = g'(x) can be true at a point x for an F and G of different degree.
if f'(x) = g'(x) for every x, then f = g + c, where c is some constant value in R. Meaning F is just a copy of G translates up or down by c
If F and G are first degree, i.e. on the for y = mx + b then yes, f'=g' means they are parallel lines
common midpoint notation is M for midpoint with the segment in subscript.
$M_{AC}$
ℝαμΩℕωⅤ
Not to mention (A+C)/2.
Does anyone, have ever seen this formula pi/(x*sin(pi/x))?
This represents the quotient between the arc delimited by a regular polygon inscribed in a circumference and the length of the side of this polygon.
let's say there's a right angle, and you're trying to find the cosine of 90 degrees. What do I do if I'm surrounded by two adjcanet angles?
you mean two adjacent sides?
the sine,cos,tan definitions in a right triangle only really apply to the acute angles
when applying them to non-acute angles, unit circle definitions are more ideal
Oh yeah I have this question too, like what exactly the difference between an expression, a formula, an identity, an equation
Especially an identity and a formula
Don't need to answer it it's a bother lol
How do I prove that G exists?
Points G1, G2, G3, G4 are the centers of gravity of triangles CBD, ADB, BCA, DAC.
what equal to? sinˆ2(x)-1
sin^2(x)+cos^2(x)=1 so sin^2(x)-1=-cos^2(x)
thanks, as i think
The center of gravity of the whole quadrilateral lies on both G1G2 and G3G4.
Thanks!
guys
i need some help
given the triangle ABC,where AB=c , BC=a and CA= b. Prove that when c=(the square root of) a(a+b) then mC=2mA
I would start by the law of cosines applied to C and A, and see if I can get derive something that looks like the double-angle formula for cosine.
anyone know how to solve this using proof?
I confused
How do you add 1/2 with 1/3
with equaling 2 and 3
Basically you need a common denominator
so multiply the first fraction by (1-sinx)/(1-sinx)
And the second by (cosx/cosx)
that'll probably lead to some sort of cancellation
the other thing that might work is this is cot(x/2) + tan(x/2)
r u fr?
r u absolutely sure ur old enough to be using discord?
if you are then im really sorry
but thats wild man
oh okay
i got scared for a second there lol
what are u solving
that’s not a question
I have this question and I solved it this way. Please someone check my solution and evaluate them if they are correct or not.
Solution for questions B. And the TSA formula for A (no need checking on this).
This is the solution for question number C
Do a normal sum
It will guide u to a more simple form
,rotate
,rotate
,delete
someone can help me calculating the area of the shaded figure? I don't really know how to start
first off, do you know how to find the area of a hexagon?
I know the formula but I'm quite lost as regards finding the areas of the semicircles
Area of a semicirlce is half the area of the circle
well that is quite obvious
can you make a guess on what the radius for each of the semicircles would be
you guys are just rotaing and filping. is not this math interesting? are these correct?
Guys Which youtube channel is better in teaching affine geometry?
no its ce and de that are equal
Where are you getting stuck
yeye
so i drew a line parallel to ab
and part of alpha is 50 degrees ofc
but i cant find the rest
ABC is a triangle, m(ABC)=90°, [AD] Bisector, |AE|=|EC|, AD is perpendicular to DE in degrees. According to these data: |BD|/|DC| what is the rate?
Anyone please?
Rate?
what does > mena with lines?
|BD| and |DC| The question asks the ratio of these lengths to each other.
Like 3k and k
pls help me with this math problem
dropping here just in case anyone else can help/is interested in helping
someone help me with the middle two problems pls
Why don't they averave
Can anyone explain how/when using double and half angle identities would be useful? I see how they are derived yet I just don't see any practical use for it or really understand the point of doubling an angle
Sorry for the late reply.
Find angle DEB
Then use exterior angle property on alpha with triangle ADB
What is the answer given
!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/
anyway, no, your drawing is incorrect.
i honestly couldnt find it. what did u get for the answer?
I got 85
I think I m wrong, I will recheck
Is it 100?
why is Euclidean geometry so hard😭
i got 100 but im pretty sure that was wron g
can you shpw your working for 85 please?
anyone here tutor?
i am having trouble with some college level trig homework, is anyone willing to help atm?
helo
show me the problem
alr one sec
ok
yeah the only issue is i gotta show my work lol
i just need to figure out how to get the answer, my professor gives credit as long as we try
first sin2theta/cos2theta=1
sin2theta=cos2theta
cos2theta-sin2theta=0
cos(2theta)=o
thanks : D
cos(2theta)=cos{(2n+1)xPie/2}
2xtheta=(2n+1)xpie/2
theta=(2n+1)xpie/4
thats it
lol
its really hard to type all these
Decide angel x so that the incline on AB is 15 deg
If you decide on a scale such that the height of the slope is 1, you can compute the lengths of the two fat lines that form the tops of the 15° and 20° angles using trigonometry. Once you have them, you have two of the sides in the right-angled triangle where x is one of them, so a bit more trig will give you the angle.
x is 40.822 degrees
!nosols
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.
what does that do
@patent root okay so i think i have the concept down for what i was doing yesterday
so i think a lot of confusion came from the fact that i was essentially solving for a new equation, not a specific value
and i didnt realize that
and also the reason why we dont just slap +2pi n at the end also became clear after a bit of thinking
(referring to sinusoidal equations)
since they're periodic there can be a bunch of solutions since the function will repeat it's output every so often (period) and so we need to generalize our answer to work for any period
and 2pi n doesnt get added onto the end because our angle needs to be represented by some multiple of x, and so since x is being multiplied, we need to algebraically malnipulate 2pi n around to keep it proportional
^^^
does this all sound right?
bump
Can someone walk me through this
,rccw
<@&286206848099549185>
Have u heard of the abc rule for triangles
ABC being sides of a triangle
Look up that formula
are you talking about the pythagorean theorem? a^2+b^2=c^2?
There’s also rules
For when the sum of two is less then or equal. To the third leg or
Or something
Like certain situations are impossible
And based off those situations
U can find all possible@values
Im not looking for hypotheticals or whatever
No
I just need an example to work off of
All possible third sides
Here hang on
Lemme@pull up the formulas I’m referring to
@bronze wind
^^
There’s an example worked out
Ok
Hope this helps 🥂
thanks
I erased it, but the procedure I followed was wrong. Like accidentally took two variables as a sum rather than their difference...why do you think 100 is wrong?
Yes, you got the idea
and if im right, whatever is in sin ---> (whatever number) <--- is the angle
no matter if it's being multipled by x, n, pi, gravitational constant
whatever is in that sin(x) thingy is the angle right?
yes, the argument of a trig function is an angle
oh wait
i have a question
in a function
where i have some f or sin, or whatever(x)
what is the ( ) called?
argument
oh okay
f(x), x is the argument
mhm
i prefer input because when i talk about inverse functions i can use the word output as well
the input of f(x) is the output of f inverse(x)
that's fine
but argument makes sense as well
argument is just alternative vocab for the same thing
sure
and so since the argument of a sinusoidal function can be multiplied by x, like i said (just to be sure), we cant just slap +2pi n at the end but rather have to divide that by whatever x is being multiplied by to keep things proportional right?
in regards to the solution set i mean lol
Yes
okay, that actually makes sense
I wouldn't necessarily put it like that, but yes
lol ill come up with a better explanation down the road, i'm just trying to make sure im absorbing it correctly and understand the logic
i like to put things simply so that the phrasing works with my intuition
You will get a better way of thinking about it when you get to things like periodic motion in physics
yeah for sure
btw i do have plans on teaching all of this math too, i just gotta learn it first lmao
i wanna teach hs algebra (hobbyist thing, like an online educator deal) but i obv need to learn how to do the math so i'm really big on clear explanations
so please be patient if i repeat the same question a thousand times, it's just cuz i'm trying to make it make as much sense to me as possible lol
I used to tutor math for extra money
lol i just wanna do it for fun
tbh, the help section here is pretty similar to what I used to do
it's very stimulating and rewarding
mhm, i dont understand anything in those help channels so i cant help as much as i would love to
if i was good at math, i would sit in each help channel helping everyone like every day but yk i gotta get good at math first lol
We probably shouldn't talk about this in this channel btw
yeah, imma go to math discussy
Hi
how do i proof that cos(x)^2 + cos(2x)^2 + cos(3x)^2 -1 = 2cos(x)^2(2cos(2x) - 1)cos(2x)
Because exponents just go to the left of the number like logs do @sage bison
what
Exponents become the coefficient
...???
Oh I read it wrong
yep i did the same thing and got 100 💀
but its the wrong method ofc
helo
Thank you
I somehow got 34 help me out
Thank you, just found that out not too long ago lol.
there are vertical angles and alternate interior angles
which should help you solve
Can someone explain why sine was used for N_1 and N_2? The angle is w.r.t y-axis.
Try finding the y component of N1 and N2 in terms of that angle
It might help to draw a really big wedge and make some triangles
yall how do i do like y = -x for graphing polygons and reflections an stuff
I still cant see it. Why don't you draw it for me so I can see what you mean.
You should try to draw it and then show me what you don't see
We can decome N1 into x and y components
decompose
I still don't get where they are getting sine from. We take cosine when angle is with respect to y-axis
and looking for y component
SAS I think
hi, please get an open channel from the list of open channels and ask there
k
isnt that geometry
the ones that are labeled help-### without a name
bruh if my explenation didnt help nothing will
u didnt
yeah but for specific homework help like this it's best to have a dedicated channel for it
ok tq
I did💀 bruh if you dont take math seriously leave this server please
where can i take my help from, could you redirect me with some channel
i did not come to this server to listen to your advises
then why did you join this server
you are just trolling and asking the same question to everyone
alright dude you need to stop being so weirdly mean, let us handle the moderation issue and you just focus on being helpful and kind
How to solve a triangle in which you know its 3 angles and its area
pick a side and call its length x, then find an expression for the area of the triangle in terms of x
what do you mean by solving a triangle
Guys, I have a triangle and I have to find the height, I know that the area is 50m2, and I have the 3 angles of the triangle, a triangle cannot be solved with only 3 angles, I have already determined that I have to find the base to get the height only isolating the equation of the area of a triangle
know all his lenghts and height
which type of triangle is it
?
acute, obtuse, isosceles or right or some arbituary triangle
or construct another triangle upon yours and make a parallelogram, take a side as base, divide the length of base by 2 times the area (100) and you get the height
if i restrict my domain, can i model my hairline using a sinusoidal function?
Guys, I want a place to practice trig equations, formulas and inequalities
Could someone help me solve this?
I’m sorry if I’m being a burden, but I’m truly stuck
do you remember how midpoint is found
afaik
its
You are given the midpoints in this case
midpoint = (x1+x2)/2 + (y1+y2)/2
Yeah
so let's consider GH part
||Bro I'm gonna try I haven't done these things in like years||
Honestly I tried but my answer was a fraction and was wrong
lemme see what you tried so far
Uhhh let me rewrite it
I have chicken scratch handwriting
Also, I’m not looking for the midpoint, it gives me the midpoint, but I need the two points that allow that to be the midpoint
don't you want the G
3, 9 = (x+x0)/2, (y+y0)/2
3 = (x+x0)/2
Cross multiply maybe
and then maybe after you use substitute equations
This is getting very confusing
I’m trying to solve for point G H and J
While point K is the midpoint of segment GH and point L is the midpoint of segment HJ and M is the midpoint of segment GJ
and it give me the places for all the midpoints
So instead of using the midpoint formula, I’d use the slope formula, right?
how's slope involved in this
Because you are finding the points that make the midpoint
I also don't get what's really confusing you rn, sorry 😦
I’m a freshmen trying to figure this out
I didn’t have a teacher today to teach this topic because we had a sub
And I was trying to ask someone to kindly help me solve it
id checkout a video on the midpoint formula
can someone help me with this
im stuck
trigo
hi
trigo is fun and geometry is madness
wouldnt you just do percentages
and then divide by 2
oh i'm talking about eclipseryu's problem
13sin(2x)-3=3 has at least two solutions.
Let the first solution be x_1 and the second be x_1. Also let n be some integer.
13sin(2x)=6
sin(2x)=6/13
2x=arcsin(6/13)
arcsin(6/13) is approximately 0.4797 radians.
By the sin(x)=sin(x+2pi) identity:
2x=0.4797+2pi(n)
x_1=0.240+pi(n)
For x_2:
By the sin(x)=sin(pi-x) identity:
2x=(pi-0.4797)+2pi(n)
x=1.331+pi(n)
^^^
This is just one example
Explain in Fortnite terms
i have not worked with percentages this whole semester
solve for x
theres two x's
the first is 0.240+pi(n)
and the second is 1.331+pi(n)
so f and g are supposed to both be 65 degrees, but 54+64 dont equal 180 and I thought same side exterior angles were supplementary?
huh
Did you already ask something similar in a help channel?
I haven’t gotten far in geometry yet so I don’t know how to explain it properly but here’s a visual to help. The reason why the same side exterior angles don’t count here is because there are three angles instead of two, but they still all add up to 180. The two red lines form a vertical angle. Two angles across from each other both equal 61° and to find the rest you subtract that from 180, giving you 119. You have a missing angle but you were given the other angle, which measures 54. Subtract 54 from 119 and you found the measurement of angle f. Another way you can do it is add all the 3 angles up and make them equal to 180 because they lay on the same line (blue line.)
ohh thank you I just was confused why g couldnt be 126 but I see it now tysm
Np
,rccw
@mint garden if you still need help, would you mind showing us the original question is?
This, it's a question I submitted but I need to have the right answer for it to be accepted
Pls help, its asking to write 2 column proofs.
-7 -4
Assuming two points A(x1,y1), B (x2,y2)
The coordinate of the midpoint(M)of the straight line AB would be
((x1+x2)/2), ((y1+y2)/2)
@astral stratus use congruence rules
are there any good vector proof worksheets? and if possible, can it include a few 3D vector questions.
how do I simplify a radical with a decimal in it?
more specifically the square root of 179.84
you could start with multiplying the inside by 100/100
applying sqrt laws leads you to
=sqrt(17984)/10
then simplify the numerator
also not geo
since it’s an isosceles and you found angle 2, 122, you would then subtract 122 from 180. Resulting in 58, after just divide by 2.
what does the greater than signs means with a line under
it is a sign of 'greater than equal to', that simply means that the thing that is being pointed with it should be greater or equal to the value there is, suppose its written x ≥ 5, this means that x can be greater to 5 and also equal to 5 at the same time @crimson pawn
for no.4 (the octagon problem) B, remember that the sum of an octagon's interior angles is equal to 1080 deg, so each interior angle has 135 deg. Now if QT is formed such that PQ is perpendicular to UT, then triangle PQT is a right triangle. So, <PQT +,TQR = 135
after this, you'd get the base angles oft he isosceles trapezoid QRST. then by refering to 45-45-90 special triangle, u should get the needed measures to find both polygons' areas
Can I have help in geometry anyone
dont ask for help, share it here and let anyone give it a try!
hm

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 know I got the minimum wrong when I did my submission but how is my maximum wrong?
Can someone review my notes please. Some geometry and trig fundamentals
neat handwriting
Thank you I'm still adjusting to the Apple pen
Some of it…
Haha Ty, do you know if the notes are correct?
im too lazy rn
wrong channel oops
Great work buddy!
handwriting's fine af like wtf 
anyways, there's some tips for the notes
- U could have added the simillar triangle theory to the trig part. It could put extra realism to the fact of the ratios of sides being same for same angles
- It'll be appreciated if u put proof of the distance formula and other associated formulas in coordinate geometry to have a better glance at those things. Cuz it's no fun understanding or learning the fundamentals of this without using graphs uk!

is sas congruence an axiom or a theorem
in some textbooks it says axiom and in others it says theorem
and the proof is really weird
so im not sure
hello guys
im struggling with trig and mostly inverse functions of cos, sin, tan, sec, csc, cot
do you g uys know any tops
tips*
Someone please help I need to find the area of multiple shapes put together and I can figure out how to do it. Dm please
- Find θ
θ =
- Using the unit circle, find the following values:
cos 0o =
sin 0o =
cos -90o =
sin -90o =
cos 135o =
sin 135o =
cos 315o =
sin 315o =
cos 60o =
sin 60o =
cos 150o =
sin 150o =
cos 240o =
sin 240o =
cos -30o =
sin -30o =
Find these values and write them in radians:
arccos 0 =
arcsin 0 =
arccos 1 =
arcsin 1 =
arccos (-22) =
arcsin 22 =
arccos (-12) =
arcsin (-32) =
arccos(-32) =
arcsin 12 =
can somone help me
Okay thank you I'll be sure to add them!
Are you allowed to use a calculator?
what did you use to write these notes? It looks nice
a
how is the angle in red circle equal to angle in green circle
they look same angle
can you recognize that they're same size angle?
idk how to explain it mathematically tbh
ikk they are same but how
like in this they are though
vertical interior angles
but what about the above one
I mean in the blue circle
what?
yea i can see lol
okay youre back again
Lol
and this one too?
Yes
Since these 2 are radius and tangent
ohh okay it doesnt look like a right angle, thats why i was having trouble
okay got it
thanks both
thx
Goodnotes
thanks
guys i just got my report card ive got all A's in math
good job
SSA criterion works for right and obtuse triangles right?
no
it just doesnt work'
ugh after 5 days of trying to comprehend how this formula is dervied (searched everywhere on the net) I gave up and instead looked at it from a different approach. So upon doing some graphs, I realized I can simply create a triangle using the lines' x&y intercepts then say line 1's x&y intercepts would be its base, and the d (which perpedicularly intersects l_1 & l_2) would be the altitude. On line 2, I can use either the x or y intercept as a point of reference. Then I can refer to the formula to find shortest distance of a line to a point, which I was able to understand (simply Height = 2Area/Base on a coordinate plane). Tadaa same result, but if anyone knows how the formula in the pic came up as it is, feel free to share!!
using green line's x-intercept as the point of ref
or using the green lines' y-intercept as the point of reference
then yeah pretty much finding altitude of triangle on a coordinate plane
where intercepts create the sides
That's actually more deep
I'd prefer doing problem solving in this way
@smoky jetty
I don't know that formula as well lol
i didnt get the procedures online so I thought maybe triangles may do the job and yeah came up with another formula that I understood well enough
which was this
but if anyone can guide me to the other formula, then id love to
If you're happy with the distance-from-a-line formula, I'd suggest this:
Convince yourself that if you remove the absolute-value signs, you get a signed distance-from-a-line formula that gives you a positive distance on one side of the line and a negative distance on the other side.
Now, apply it to a fixed line through the origin with equation ax+by=0 (that is, no c).
Then you can use it to find an equation for all the points whose distance to your fixed line is some number d:
(ax+by)/sqrt(a²+b²) = d <==> ax + by - d·sqrt(a²+b²) = 0
And if you do that once again for different d, say d', we have
ax + by - d'·sqrt(a²+b²) = 0
Thus, the c's for lines at various distance from our fixed line are just their distances times -sqrt(a²+b²).
If we have ax+by+c1 = 0and ax+by+c2= 0, then their distances to the fixed line are -c1/sqrt(a²+b²) and -c2/sqrt(a²+b²).
The differences between those is the distance between the lines, in other words |c1/sqrt(a²+b²) - c2/sqrt(a²+b²)| and you can now lift the division by sqrt(a²/b²) out of the absolute value.
i didnt get what u meant, could u rephrase this?
I meant:
$$\frac{ax_1+bx_1+c}{\sqrt{a^2+b^2}}$$
is the "signed distance" from $(x_1,y_1)$ to the line $ax+by+x=0$, in the sense that its \emph{magnitude} is the actual distance and its \emph{sign} tells with side of $ax+by+c=0$ the point is.
Troposphere
what do u mean by "signed distance"? is it sort of like the raw value of distance even if it's negative?
could u elaborate this?
im not that familiar with "magnitude" in this sense
"Magnitude" = "absolute value".
I can't immediately think of a different way to say that, other than just repeating myself.
The sign will be + on one side of ax+by+c=0 and - on the other side.
it's alright, but can u like graph/draw it?
coz im tryna connect that to this (your prior response)
hmm how would the result look like?
Umm....
i mean in the equation (mb if im confusing atm)
I'm sorry, I confused about what it is that's confusing you.
ig to make it less confusing, do u know how this formula was derived? If u could, can u show your process and ig some bits of explanation, then i'll just ask/clarify parts of it
i couldnt comprehend to your response a few hours ago, sorry😔
That's what I was trying to explain a derivation of, starting from the distance formula that it sounded like you had already proved to your own satisfaction!
i see, must've been my comprehension to new math concepts
im gonna try to understand it again later
As someone who is doing algebra 1 that looks super impossible to answer
still having a hard time understanding, but do u think that the distance from a line to a point formula is sufficient enough to use for distance betweeb parllel lines?
neeeeed hrlppppppppp
Yo anyone good with trig ratios? A quick and simple question
how can i get ADE = EDI
is ED a bisector?
@grave pond (sorry for the ping)
@smoky jetty what exactly is your question
tl;dr above: I don't know how distance between parallel lines was derived so I instead used the concept of distance from a point to a line (which I learned how it was derived) and got the same distance anyway. Troposhere showed the derivation which I unfortunately had a hard time comprehending. So Im asking if the distance from a point to a line should do fine for parallel lines.
to not bother him more on making it more understandable, and I think I've already spent 6days trying
from what i studied, i had 2 different formulaes to find distance b/w 2 lines and distance between a line and a point
!Yajat!
this for parallel lines
!Yajat!
yeah there are 2 formulas, but I realized, the intercepts can serve as reference points for the second formula u shared
tho i have thee derivation of these formulaes
i learned the derivation of distance-from-a-line-to-a-point, but I couldnt understand the one for parallel lines
might be slacking in comprehension and algebra
i'd love to see how u derived it
these are my notes
tell me if you understand it
x=0 and y=0 in this case
lines are ax+by+c_1 and ax+by+c_2
you can notice how a and b are same for both the lines
its because they are parallel lines
!Yajat!
like we have already derived the formula to calculate distance between a point and line, we are taking help of this formula to derive this result
oh wait omg
WOWW
holy crap
no fcking way lmaoo
so these lines or pretty much any line as long as they have the same slope, would have the same A and B constants? When transformed to general form
i mean those conditions are for parallel lines so yea we can use this formuka
also
not necessariliy the coefficients have to be equal
like consider 2 equations
!Yajat!
they do not have same coefficients rn
but you have to diviide the equation by 5
then it would have same coefficients
right!
yea
just this
yeah
if it follows this you can use this formula
you can pick random equaitons, plot them on desmos and you can see that they are parallel
equations that follows this would be parallel
so basically if two lines are parallel, their A and B constants must be proportional, then we can just exclude it in the formula to find distance from a point to a line, resulting in |C1-C2| numerator?
to find distance from a point to a line
is this a typo?
u mean from a point to a line or between 2 parallel line
yeah from point on the parallel line to the parallel line, but since they're parallel, we can reduce Ax1 and By1 in the expression?
yes as x and y are zero here
whats the length of d_2 in this case?
!Yajat!
i mean is the point of ref also the origin?
yes
OHHH
it is origin
now everything makes sense!
yea
basically subracting the distances of two lines from origin, right? but since parallel lines have proportional A and B constants, we can just cancel them out in the expression?
!Yajat!
@smoky jetty
i see!
Here was my work on deriving it, tell me if there are mistakes in reasonings and stuff
yeah, this got me confusing as well
lol
oh wait nvm
okay for better clarifiaction lest just solve for the distance between lines 3x+4y=10 and 12x+16y=7
when you divide the second equation by 4 it givess you 3x+4y=7/4
now you have 2 equations 3x+4y=7/4 and 3x+4y=10
can you see now how a_1=a_2=a?
and b_1=b_2=b
lmao hold on lemme think more
yeah they are proportional, but if a_1 = 3, and a_2 = 12, how can a_1 = a_2?
i still dont see how a_1 = a_2 😭
but if those gen. form equations were transformed to slope-intercept form, I could see that a_1 = a_2
@thick fable
sorry but its literally the same thing i was telling you to do
what happens when you divide second equation by 4
tell me
yeah you'd get the same
since they're just the same when we transform standard form to slope intercept form, we can already say that in parallel lines a1=a2=a?
yeah but I just couldnt grasp around the idea that a_1 is already equal to a_2 and is equal to a, when u actually must first divide a_2 by smth (e.g. coefficient of y > 1 in a slope intercept euqation) to make a_1=a_2=a
exactly! ig a_1 = a_2 = a only after transforming the equations to slope intercept form
The equilateral triangles ADF and BCE are constructed outside the square ABCD. If
DE ∩ CF = {G} show that △ABG is equilateral.
need some help with this one...
from (so, a=b) I changed the reasoning @thick fable . Is this more accurate?
If a single point is removed from a line, do the remaining points form a convex set?
No because of the point removed is P and you take two points Q and R on opposite sides of P, then the line segment QR contains P but P is not in the set.
Thank you for the response. I was quite confused because someone claimed on the internet otherwise.
yea it is correct but i dont know why are you saying slope intercept, like its necessary that you have to simpify it in slope intercept
oh I just elaborated why a_1 = a_2 = a
since it might be confusing to assume that initially, a_1 = a_2 = a already
hm yea
alright man, I really appreciate your help & clarifications. Forgive me if I have been pretty confusing/lost earlier, but yeah thanks for easing things up for me ❤️
np!
Hi, is there any proof/explanation for why this works? Ive tried it on some examples and it seems to work.
How do i find x, ive already found y
pls help i got the class in 1 hour
u're given two isosceles triangles
90 - (2y+64) - x/2 = 0
what do u know about an isosceles triangle's property
2 sides r equal other isnt
90 - (2y + 64) = x/2
x = 180 - (2y + 64)
dont give out answers prematurely, !
Isn’t the text in the picture the explanation?
Notation errors notwithstanding
you know y so other side of that is 180 - (2y+64)
and another triangle is Saquin parallel triangle so
(45 - x/4) * 2 + (180-(2y+64)) = 180
easier answer
thank you so much
So apparently it's called the normal form of a line or the shortest distance from a line to origin. I tried deriving its formula and got this. Is it correct?
theres also this sort of other ver. of the formula: x cos a + y sin a = p
where angle a is the angle created by the perdendicular line d with the positive x axis
@smoky jetty what is the second equation sorry
in the picture?
yes
this?
theta? those are zeroes in parentheses
I mean why is the cos value equated with 2pi. Why does it work? Thats my question. More of a logical question so I can make sense of it in my head instead of just memorizing.
can someone pls help me with this question?
do i need to use the angle bisector theorem?
Because it's periodic with 2π, which means that we'll get the same value everytime we move 2π
I hope that I understood your question and that I answered it
Ok, maybe this helps:
Fact 1: cos(2 * n * pi) = 1 for every integer n
Now when is 2pi/3 * m of the form 2 * n * pi?
Answer: when m is a multiple of 3
can someone help me
is this correct @thick fable ?
ight this one is pretty understandable
Yup, you did. Thanks!
Thanks 🙂
When do you flip the sign of an inequaltiy? (I've looked online, can't find anything clear...)
it says that- two right circular cones x and y are made. x having three times the radius of y and y having half the volume of x. calculate ratio between the heights of x and y.
its inside the mod so you have to take 2 cases when c>0 and when c<0
mod?
yea
now make one more case with -c and show this when c<0
thats the basic definition of moldulus
How do I find AB
Could you send a picture of the problem ?
I guess you work with complex numbers? I’m Not at that level yet, but afaik, we do it because the degrees would be above 270 in the 4th quadrant. Cf. The picture
afaik 360 is subtracted to an angle in 4rd quadrant since the result is the positive coterminal angle of that angle, which is an acute one
and a reference angle for the trig functions & ratios
y is 10
but how to find x
idk
You can find the intersection of line AP and BP
And for the equations of line AP and BP, you have a cordinate for both so you just need it slope
It's*
AP=BP are equidistant
its fine
i found it
using
dist formula
Cool
Does this count as an octogon?
I think so
No it has like 11 sides
Well from where it bends it has 11 lines
eye lvl 2000
can someone help me with this pls?
to make it easier
<B = <ABD = <ABC
<C = <ACD = <ACB
<DAC = 2<DAB
and as in shape we know that
<DAC + <DAB = <BAC
3<DAB = <BAC
2<BAC = 3<B
2 *(3<DAB>) = 3<B
remove 3
2<DAB = <B
<DAC = <B
and we know that trianlge have 180 deg inner angle
180 = <C + <BAC + <B
180 = <C + <DAC + <ADC = <C + <B + <ADC
<C + <B + <ADC = <C + <B + <BAC
remove <C + <B
<ADC = <BAC
we found that triangles CAD and CBA have same angles
so there is a x that
BC * x= AC
AC * x = CD
AB * x = AD
ax = b
bx = e
cx = d
and about x you can use first one
ax = b
x = a/b
sorry for my bad english if you don't get something ask me
you don't need sin
wait ive got another sol
sin lead you to wrong answer trust me
look
A is 3x
and <CAD is also 3x
so all angles on CAD and BAC is same
so that sides multipy by same number
we call it a
let me check
k
(this is another x)
x is b/a
so
(b/a)* b = b^2/a
cx = bc/a
yep
our answer is same
but I made a small mistake in last
(come on I calculate all of it in just chatbox not paper)
i wrote ax =b so x = a/b
but it's x = b/a

ye
yw
already did the assignment but is it possible to reflect the pre image to the image in under 3 translations (other than reflections cannot go through the grey)
reflect over y axis and then rotate it twice
wouldn't work
and i said in under 3
how do i do this??? im so lost
i just wrote whatever i thought it was but i actually have no clue how to solve it
!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/
what about this was worth da2a'ing about 
trigonometry relates ratios of lengths to angles using trigonometric functions
use sss congruence by using the distance formula
consider the range of sin^{-1} carefully
well depends on if its degrees or rad
if rad then like 2 is in 2 quadrant so
make it first
The range is -90 to 90, right?
Yeah as the assignment doesn’t mention whether it is in radian or degree.
It should be in radian
you take it as radians if it does'nt clarify it
Ok
wait is the answer for this guys
What is measurement of the indicated angle assuming the figure is a square?
do I have to use it for every single side until I get the answer or do I only need to use it for any one side
can someone explain to me what is the "equation of a line", and how to derive it ?
Hello i have a problem
Hello! How can I assist you today?
Let ABC a non-isoscelis triangle with orthocenter H and the feet of altitudes A1, B1, C1. Let A2, B2, C2 be the projections of H on B1C1, C1A1, A1B1. a) Show that the circumscribed circles of HA1A2, HB1B2, HC1C2 have 2 points in common. b) Show that the circumscribed circles of HAA2, HBB2, HCC2 have 2 points in common.
How can I find the OO' segment?
B is an intersecion of the circunferences, AC // OO'
Can I do this?
Corresponding angles is a postulate but like
My teacher said you can’t prove it but surely you can right
Is this the right direction ?
If I wrote a,b,c as lines in slope intercept form
And their slope would be tan(their angle off of the x axis)
and I say a circle is the angle of a off of the x axis and same for b circle and c circle
Then can I do that
I really wanna know where I went wrong because it is a postulate so it can’t be proved but this looks ok to me
no every side
unless u trig ash to find 2 similar angles
but thats harder than just finiding the dstance
its calleld sss for a reason
what do you mean by deriving it
translate the question please
wait what do u mean
Like
The line that has a y intercept of 0 and is 45 degrees off of the x axis
Is y = tan(pi/4)x
So u write all the lines in this form and show c and d have the same angle
And thus the same slope
So they are parallel
d?
b*
Typo
So why am I wrong
Is it not a postulate ?
How can you prove a postulate
I added more to the proof
I also showed linear functions can be represented that way
how can u say that slope of line a would be equal to slope of line b and c?
@tawdry condor also i quite dont get what you main objective here is, like are u trying to prove how corresponding angles are equal?
I didn’t
I’m trying to prove if two corresponding angles are equal, then the lines are parallel
Converse
Since they share that angle
I wrote them in relation to the transversal and that angle
They have the same slope parallel
So uh
they share equal angles off the x axis so thier slopes are equal that means they are parallel?
dude u there?
@tawdry condor
how do you discover it? how do you come up with it ? how does it work ?
that is just a general form of a straight line
Why is this form used, in which the slope is not apparent:
ax+by+c=0
?
f(x)=mx+b is intuitive , m is the slope
ax+by+c=0 is not intuitive, and I am trying to find some intuition
that is just a general form of a straight line, f(x)=mx+b is derived from this form only
Yes
So is my proof valid then
The setup
i mean we can make this whole transversal like the b and c line parallel to x-axis
No
I just drew them like that
But I didn’t make any such assumptions in the math
sorry but your handwriting is just not redable
oh ok
lol it’s fine
Does my logic work
Is this proof ok
yea those angles can only be equal if those lines are parallel but im not sure about it, i mean the logic seems correct
Fire
Can someone please help me through this question? I know the steps I think but I've made an error somewhere as my answe doesn't seem right
you know its a right angled triangle, you can use pythagoras relation to find the vvalue of k, and then use 2 point form to find the eqaution of the line @slow path
I don't know the length of 2 lines though
use distance formula for that
And I did it a relatively more complicated way but I've ended up at 2 points
Could you double check that k=9?
I have an answer that works woohoo
i aint solving anything showme your work tho
So which sides for example would I need to find
i literally said all of thekm
hello my friends
???
context?
wdym, like the problem? cause its showing how to round 9 pi
yes
thx
Can someone help me understand how to get F? I have a slight intuition but this is finding F(θ) where θ is a defined angle between the X-component of the normal vector, and the normal vector. Where the addition of that angle, and the angle between the negative X-component of the normal, to the normal, equals 180°.
Two things I've noticed:
F(θxz) = 3π/2 when θr = θxz
F(θxz) = π/2 when θr = θxz + π/2
Anyone has the xbox gamepass 3 months code and doesn't need it
can you do out an example for me
i had a friend who had it but didnt neeed it, but it expired
10th grade trying to solve a 12th grade (according to the one who posted it) problem, I’m stuck pls help
Haven’t learned trig yet if it helps
you made a mistake in solving the angles of the triangle ABE, their sum is 68, they aren't 68 each
Oh ur right
what value did u get?
I tried to find it by angle-chasing, still got nothing after 30 mins
Lmao I'm not gonna solve that, just sharing what I got
Though Its probably not that difficult to solve it using trigonometric identities
although I think I'd get the answer rn if I plug in each given choice to angle ABF and if it matches with other angles that I found. But I think it'd ruin the fun out of it XD
could someone help me touch up on some geometry for 8th grade?
is your teacher like not doing their job or is this like a personal thing
