geometry-and-trigonometry

[trim sand]

@@silent rover no no im in high school

Why would I be doing maths as a med student 😅

[upper karma]

for advanced medicine you need physics which requires math

and you need other math

although if u were a med student and only doing basic trig that would be pretty sad

[silent rover]

@trim sand oh lol it’s cuz the background has like Medical written on it

@upper karma ahh i see

[upper karma]

I mean I'm fairly certain that you couldn't even pass the MCAT let alone be actually studying in med school if you were only at that level of math

[trim sand]

@silent rover its a institute they prepare students for both engineering and medical exams

[inland canyon]

@silent rover i need more help lmao

i understand tan tho

[upper karma]

I haven't done trig in a while so if it's more abstract trig I won't be able to help

[silent rover]

@inland canyon sure

[upper karma]

but I might be able to help depending on what it is

oh nvm

[silent rover]

@upper karma pls join ahaha if you’d like, combing forces :’)

[upper karma]

sure

what're they confused about?

[silent rover]

they haven’t replied so i idk too

[inland canyon]

ok so

my problem is set up this like

[upper karma]

and to find x?

[silent rover]

do you know what rule to use

[inland canyon]

i need to find e to f

[upper karma]

ok, do you remember what the trig functions are

[inland canyon]

ok so

ik its not tan

[upper karma]

u may have learned it as sohcahtoa

[inland canyon]

i think its cos?

[upper karma]

wait are you alllowed to use a calculator?

cuz it becomes a lot more difficult if no

[inland canyon]

ye i can

[trim sand]

Its sin right?

[silent rover]

cos(angle) = A/H

[inland canyon]

so it is cos?

[silent rover]

does the question give u info about adjacent and hypotenuse @inland canyon

[upper karma]

well think

[trim sand]

The opposite one is given

[inland canyon]

ye

[upper karma]

do you know which one equals opp/alt

[inland canyon]

not yeah to you jia

ok so i know side FD is opposite of angle e

[upper karma]

also I assume not, but have you done a unit circle?

bcuz it will be easier to explain that way

[inland canyon]

nope

[upper karma]

ok

[inland canyon]

i just know FD is opposite of angle e, so like it wouldnt be tan

[silent rover]

we did unit circle after trig lol, so before unit circle it was just memorising

[inland canyon]

(right?)

[upper karma]

so basically what you're trying to find is line segment EF, and you're given line segment FD

[silent rover]

@inland canyon why wouldn’t it be tan?

[inland canyon]

uhhh doesnt tan have to deal with the opposite

[silent rover]

recite the tan rule sir @inland canyon

[upper karma]

yea

[inland canyon]

isnt tan used in trying to find the opposite

[upper karma]

coffee? ☕

[inland canyon]

i already have the opposite

[upper karma]

well sort of

in this type of question

[silent rover]

tan is not just for opposite

it’s also for adjacent

[upper karma]

you just want whichever function will relate to the variable and to the information that you have

[silent rover]

because tan(angle) = opposite/adjacent

you transpose it differently based on what you’re trying to find

[upper karma]

do you know if line segment EF is opp alt or hyp?

[inland canyon]

is alt adjacent?

[upper karma]

yea

[inland canyon]

the angle is alt with the opposite then?

[upper karma]

sorry I meant adj

I'm tired rn so my brain isn't really functioning

[upper karma]

yea

[inland canyon]

that would be adjacent right

[upper karma]

yes

[inland canyon]

alreight

alright*

[upper karma]

so you have data for opposite correct?

[inland canyon]

that would be 32

[upper karma]

and you have a variable for adjacent

[inland canyon]

34

?

[upper karma]

no the x

[inland canyon]

ohlol

[upper karma]

I meant line segment EF

[inland canyon]

ok yeah

[upper karma]

that's what you're solving for, it's the variable correct?

ok, so you need whichever function includes adjacent and opposite

[inland canyon]

yes it is

[upper karma]

because the way you would solve this

[inland canyon]

oh

so it is tan?

[upper karma]

do you understand why tho?

cuz it's not useful unless you understand why

[inland canyon]

because it deals with opposite and adjacent?

[upper karma]

yea, but do you understand why we need the function that deals with opposite and adjacent

it's alright if you don't

[inland canyon]

becauseitsoppositeandadjacent

[upper karma]

ok, basically when solving this type of question

wait hol up

I need a drawing program rq

I'll ping you when I've finished finding and drrawing one

[inland canyon]

well i mean before that

wouldnt the answer be like

[silent rover]

@inland canyon does this help

[inland canyon]

oh yeah

imma save that rq

but the answer would be like

21.6 right

cuz i gotta round to the nearest tenth

and the 5 would round up

[silent rover]

nope

tam(34) = 32/x

since x is at the bottom this time, u need to multiply both sides by x this time

do you get why ?

[inland canyon]

wait

so would i do like

wait

so

so so so

i wouldnt do tan34 x 32

[silent rover]

nope

[inland canyon]

whynot

oh

because x is at the bottom

[silent rover]

thats a way to memorise what to do

but im guessing you dont understand why ?

[inland canyon]

nope

so what do i do then?

if i dont like do tan34 X 32

[silent rover]

this is what happens if u multiply both sides by 32

you still can’t get x by itself

[inland canyon]

so

how does one

get x by its self

[upper karma]

this is why you want to use tan

[upper karma]

sry it took so long

[silent rover]

ok this is what happens if u multiply both sides by x, do u know what to do to get x by itself?

[upper karma]

@inland canyon you can solve a basic algebraic equation like 1=3x correct?

it's ok if not, but you should review it if that's the case

it's needed for a lot if not all higher math

[silent rover]

@inland canyon i hope this helps

its called transposition, u can look up videos of it on youtube?

[inland canyon]

sorry i was getting some food

also no

[silent rover]

it might be confusing at first but it becomes second nature real quick

[inland canyon]

i dont know how i would get x by its self in this situation

[silent rover]

and dude, u need it for everything im telling you

[inland canyon]

chief imma be honest

i cheated on alot of algebra when i had it

this is like the first year in a while ive been like

[silent rover]

HAHAH

[inland canyon]

focused on grades

lmao

[silent rover]

its not too late :)

[inland canyon]

like i can do some algebra

but yeah

but also like

how would i get x by its self in this situation, because i was under the impresson of if its tan u would do like

tan(the angle) x (the side)

[upper karma]

ok, so here's the problem

tan (the angle) = a number, correct?

[inland canyon]

are u asking me this

ifsoyes

i think so

well

it would have to right

[silent rover]

yup

[inland canyon]

okso

when u do tan

the tan is always the angle?

[upper karma]

sort of, in this instance

you would plug in tan to your equation.

we already got that tan(θ)=opp./adj.

so we can plug in the value for tan, and the values for our opposite and adj

in this case it would be tan(34)=32/x

correct?

[silent rover]

uh wtf ive been eating a mouldy bagel this whole time

ok back to maths

[upper karma]

@inland canyon

[inland canyon]

did it taste good?

[upper karma]

did u get what I said

viper did u get what I said

[inland canyon]

yes

i did

kinda

lemme rephrase in a way

[upper karma]

go ahead

[inland canyon]

since its adjacent you would do the adjacent side times the opposite?

[upper karma]

wait wait wait ur jumping ahead

you get that tan(θ)=opp./adj. right?

[inland canyon]

yes ofc

[upper karma]

ok so we have our values

what is our tan value, our adj value and our opp. value

[inland canyon]

ok the tan value would be 34?

correct?

[upper karma]

yea, now what is the opp. and the adj value?

[inland canyon]

the adjacent value would be x

and the opposite value would be 32

[upper karma]

GOOD

ok, so now what's the actual value of tan(34)?

basically at this point you just have to plug in your values to your equation tan(θ)=opp/adj

[inland canyon]

21.58

21.584272538957652228558747583828

is like

full thing

[upper karma]

yea just use 21.58

ok, so based on what I said what do you think the next step would be?

[silent rover]

@inland canyon isnt 21.58 the value u got from tan(34) x 32

[inland canyon]

oh yeah shit

lemme go back

[upper karma]

oh lmao

[inland canyon]

0.674

is tan 34

[upper karma]

ok good

[inland canyon]

ok so the next step would be like uhhhhh

0.674 times x maybe?

[upper karma]

basically what you have rn is an equation: tan(θ)=opp./adj. and you have values: tan(θ)=tan(34)=.674, opp. =32, and adj.= x

so think what you can do with this

[inland canyon]

u could do like

tan(34) x opposite = x?

but thats wrong isnt it

[upper karma]

almost

ur aaaalmost there

wait

[inland canyon]

what am i waiting for

[upper karma]

one second I'm trying to think how to phrase this

[inland canyon]

ok

[upper karma]

basically how did you get the opposite on the tan side?

[inland canyon]

take ur time chief

because the opposite is opposite of the agnel

angle *

[upper karma]

we don't have to worry about the angle, all we have to worry about is our equation and our variables rn

[inland canyon]

didnt u just ask how like

i got the opposite

[upper karma]

yea, I was expecting something else

cuz like u were aaalmost correct

but apparently it was for the wrong reason

here one sec, lemme try and find a program that I can share with you

that should hopefully help

sorry for my crap teaching skills

[inland canyon]

dude i mean shit

anything helps

[upper karma]

ok sadly it's a drawing program but should help

can you vc it will make it easier to explain

it's alright if no

https://aggie.io/paf7l2_gw9

oops

didn't mean to remove the embed

https://aggie.io/paf7l2_gw9

@inland canyon can you vc?

[inland canyon]

ye

[silent rover]

lol i came to listen

[upper karma]

0.674=30/y

0.674y=30

[inland canyon]

0.674y=30

[upper karma]

y=30/0.674

tan(x)=opp./adj.

tan(x)=opp./x

tan(θ)=32/x

[inland canyon]

0.674=32/x

[upper karma]

5x 5/6

5/1 x 5/6

[inland canyon]

25/6

[upper karma]

5x

[inland canyon]

0.674x = 32

0.674x/0.674x

0.674/0.674?

[upper karma]

2x5/5

[inland canyon]

0.674x / 0.674

0.674x / 0.674 =

0.674x / 0.674 =32

47.47

In def the measure of f=90, the measure of 3=34, and fd = 32 feet. find the length of EF to the nearest tenth of a good

foot*

[silent plank]

math is case sensitive

anyway what's the issue you're having atm?

[proven herald]

hello whos good at trig

[upper karma]

oh I helped him, we were vcing which was why it looked so weird

I mean I haven't done trig in a while

so depends how abstract ur trig problem is

butt as long as it's not something crazy I can probly help

[proven herald]

let me show you one second :))

[upper karma]

if it is then you'll have to let me research for a bit

Will someone be able to help me with some geometry homework I have a test on Wednesday and I’m having a problem with some problems

hold up, I'm supposedly helping someone atm

Ok no

Np

nah, I can get to u in a moment

👍

while I'm waiting can u send in the problems

Sure

and I can see how long it'll take

[proven herald]

its this kind of stuff

[upper karma]

I’m only in 9th grade so mine will prob be ez for u

ok, so what kind of problems are you having @proven herald

[proven herald]

i'm just not sure how to read this

and find the closest left shift

[upper karma]

Do you want me to just send a tutorial?

https://youtu.be/maOaKIR65d8

the concepts describe should help

[proven herald]

thANK you so much nautilus i will watch it

[upper karma]

@upper karma I can't quite read it, could u zoom in

ok, lemme know if it isn't the right thing, I haven't watched it just assuming

if it doesn't help lmk

Sure one second

Those r the ones I’m having problems on

ok, so I haven't take geometry since like 5th grade, so I don't remember the detail of proofs needed.

for the first one are you allowed to just say angle ABD=1/2 angle ABC cuz of bisection

or do u need further justification

@upper karma

Ah I see

I think I’m going to just look for some YouTube channels

But thank you for your help

ok, I can provide more justification if u want

but other way is fine as well

[lunar sand]

correct?

[silent rover]

yup

[next jackal]

what does mapping a plane onto itself mean?

[next jackal]

<@&286206848099549185>

[silent rover]

https://www.physicsforums.com/threads/mapping-plane-set-into-onto-itself-what-exactly-does-this-mean.911122/

@next jackal i have no idea myself but this might help ?

[next jackal]

yes this helped 🙂

why is a line defined like that?

$L'= L_p'$ ?

[somber coyote]

lazypawtato:

[dark sparrow]

@next jackal this is bad layout but i think what they meant is they use this notation with or without the subscript $P$ (which is uppercase!) depending on whether the point $P$ needs specification or not

[somber coyote]

Ann:

[dark sparrow]

basically $L'_P$ is heavier than just $L'$

[somber coyote]

Ann:

[next jackal]

Heavier?

BTW people clarified in chill that the definition is overcomplicated, just defining the perpendicular line as L' is enough, they said...

[dark sparrow]

heavier as a notation

[next jackal]

okayy thanks

[void wind]

Can somebody help me understand the foruma for double angle in trigonomtery:
cos(2v)=cos^2v-sin^2v= cos^2v-1=1-2sin^2v

Which one is the final formula that you can use on a problem? Can you use all of them depending on the problem or is the " 1-2sin^2v" the final version f you understand what i mean 🙂

[dark sparrow]

Which one is the final formula that you can use on a problem?
none of them is "final"

all three have their own use cases, and sometimes one is more convenient than the other two

[void wind]

oh, ok thanks 🙂

but sin(2v)=2sin(v)cos(v) only has one formula right?

and if cos(v) is not given you have to find it yourself with the help of trigonometric one

[dark sparrow]

this one has no other useful forms yes

[void wind]

Thank you so much! 😄

[void wind]

Can somebody this as well about the addition formula for cos and sin.

How come cos(u-v) uses plus but cos(u+v) uses minus?

Is there anyway i can find evidence for this? The explanation in my book is cray cray

[dark sparrow]

well you know cos(0) = 1 right?

[void wind]

Not really :/

[dark sparrow]

bruh

[void wind]

Im gonna google it

🤣

Yes ik

[old maple]

😟

[void wind]

Lmao, ik what you mean now i just forgot

[dark sparrow]

ok so try calculating cos(0) as cos(u - u) using that formula up there

[void wind]

Ok

So i add 0 to (u)? Or one?

[dark sparrow]

no you're overthinking it

[void wind]

Yes i am lol

[dark sparrow]

just expand cos(u - u) according to that formula as cos(u)cos(u) + sin(u)sin(u)

observe that this becomes an instance of the pythagorean identity

[void wind]

Oh okok one min

Nah i don’t get it 😭

How you get 4 different things out of that

[dark sparrow]

??

wym 4 different things

[upper karma]

cos(u-u) = cos(0) = cos^2 (u) + sin^2 (u) =1

[dark sparrow]

what 4 different things

[void wind]

U get cos and sin

From cos(u-v)

[dark sparrow]

wait, did you want intuition on why it's true or did you want a full-on proof of the identity?

cause i attempted to provide a bit of the former

[void wind]

Should i think like this? (Cos,sin)

[dark sparrow]

i mean, sure?

[upper karma]

From cos(u-v)
@void wind

[dark sparrow]

like look LITERALLY all i did was apply the identity you put your pen next to

[void wind]

I want the proof. Because i would like to understand how i can get from cos(u-v) to that. Because the book just jumped over everything and said this is the proof and not how i can solve it

[upper karma]

the proof is kinda complicated,,

it uses a bit of geometric construction

[void wind]

So should i just accept it? 😊 and memorize it

[silk patio]

No the proof in his book is the nice proof

It’s really simple

It’s using the cosine rule

[upper karma]

i haven't seen the book's proof you meant

[silk patio]

He just sent the picture

[upper karma]

it's written in a foreign language

[dark sparrow]

aight

[silk patio]

its a picture lol

It’s universal

[void wind]

There is no explanation for it. Just the formula

[dark sparrow]

@void wind are you ok waiting about 5-10 minutes as i reproduce the visual i usually give people for proof of this identity?

[void wind]

Yes 😊

[dark sparrow]

alright.

[void wind]

Thank you so much! @dark sparrow

[silk patio]

His book literally has the proof right there

The nice one

[upper karma]

https://www.youtube.com/watch?v=iqbfuLPYUx8&ab_channel=LeixB

@void wind

look at the picture of the tumbnail

[silk patio]

They are the ugly proofs

[dark sparrow]

yeah actually that's the one i was gonna do

guess stunk beat me to it with a video

[silk patio]

Dude look at the picture and apply cosine rule

[void wind]

Okok i get it now

[silk patio]

You sure?

[void wind]

Yea i think, if i use cosine rule i can

Whats the word, like prove (?) cos(u-v)

[silk patio]

2-2cos(u-v) = (cos(u)-cos(v))^2 + (sin(u)-sin(v))^2

There look

Easy and natural

[void wind]

Writing it down 😄 one sec

[upper karma]

😳

[void wind]

Bro im dumb pls 😂

[silk patio]

It’s in your book dude

I see it

[void wind]

Lol

My bad

I hate this book 🤦‍♂️

[silk patio]

You can do something similar for sin(u-v) by using the area

And calculating the height of that triangle

But calculating sin(u+v) is more natural

[void wind]

Alright, thank you so much for helping, all of you 🥺

My book is very VERY bad at explaining... it’s insane

[lunar sand]

im not sure what to do after this

[upper karma]

Divide ?

[junior light]

Multiply and divide by the conjugate of the denominator?

[lunar sand]

would the answer be 2

[junior light]

Yes.

[upper karma]

I mean

√2i/√2i=1

6/3=2

[humble pulsar]

$\frac{\sqrt{-72}}{\sqrt{-18}} = \sqrt{\frac{-72}{-18}} = \sqrt{4} = 2$

[somber coyote]

moshill1:

[upper karma]

Nah

Wrong

√a * √b = √(ab) only when a and b are non negative

[zenith ember]

Don't delete mod pings. They still show up as notifications, so it just makes us have to dig to find why we were pinged.

[old maple]

oh ok sorry

[zenith ember]

In this case, cheater offering money was banned.

[old maple]

yep your welcome 🙂

[tired knoll]

I have a quick question
my problem says "m∠ABE=40°30’"

what does 40 degrees 30 mean

[upper karma]

40°30' is 40 degrees 30 minutes

[tired knoll]

what does 30 minutes mean

[upper karma]

It's another smaller unit to measure degrees we could say, 1 degree=60 minutes

The same way seconds exist too

[tired knoll]

oh so 40.5 degrees?

[fallen bramble]

Minutes and seconds of arc are both ways to divide degrees

[upper karma]

oh so 40.5 degrees?
Yes

[tired knoll]

thanks a lot, small thing big difference

[humble pulsar]

isnt degrees minutes seconds the base 60 measurement?

[upper karma]

Wdym

[silent rover]

not sure if this is the right place to ask, but how did they get 150° ?

i get that it’s 30° there but where did the 120° come from?

is it because its 60 degrees down there and 180 - 60 = 120 ?

[upper karma]

is there some more info

@silent rover

oh hadn't read the numbers

[silent rover]

im thinking its because of this rule ?

[upper karma]

doesn't it tell you here

[silent rover]

yup like that

i was asking how is the angle between 8N and 10N 150

but i figured its because of the cointerior angle rules ?

[upper karma]

angles in a triangle add up to 180

[silent rover]

yupp

thanks a lot @upper karma

[upper karma]

np

[rose tulip]

How do we know C is a transversal point? Is it because AB and DE are parallel?https://youtu.be/R-6CAr_zEEk

[granite elk]

Anyone know how to solve this vectors question?

I already know it does this but what now

[versed river]

there should not be i's and j's under the square root it should just be sqrt(5^2+k^2)= etcetera

[granite elk]

yeah i removed them already

sqrt(25+k^2)=sqrt(4k^2+4)

[versed river]

so square both sides

[granite elk]

im a dumbass

ty

3(k^2-7)

k=sqrt(7)

ty

[upper karma]

google

[steep temple]

Can someone show me a case in which supplementary angles are not adjacent?

Are they synonyms for each other and I am just misinterpreting the first google result?

[granite elk]

The supplementary angle here just happens to be adjacent too

[silent plank]

i could draw a 100° angle and a separate 80° angle 1km away
and those will be supplementary

or a common case: co-interior angles on parallel lines

[humble pulsar]

supplementary just means they add to 180 degrees, there is no inherent need for them to be adjacent

example: the angles in a triangle are supplementary

[signal hemlock]

wtf why doesnt cos^2(x)=1/2 give same solutions as cos(2x)=0?

[humble pulsar]

@signal hemlock do you know the double angle formula(s) for cos(2x)?

[signal hemlock]

cos^2(x)=1/2 multiply by 2 on both sides to get 2cos^2(x)=1 and move 1 to left side to get 2cos^2(x)-1= now left side = cos(2x)

so cos(2x)=0

now solve for that

if i instead take sqart of the inital equation i get cos(x)=sqrt(1/2)

and i get all 4 solutions

with previos method i miss out on 2

[humble pulsar]

give me a min to read that over

[signal hemlock]

ty

want screenshot?

[humble pulsar]

no i should be good, just need to digest it

Ok right

cos(2x) = 0 -> 2x = pi/2, 3pi/2 right?

[signal hemlock]

cos(2x)=0 -> 2x =+-(pi/2)+2pi*n

ye?

[humble pulsar]

yeah but you said 4 solutions which implies a restricted domain of [0,2pi]

anyway you get 2 solutions to cos(2x) = 0 since there's only 2 roots of cos within [0,2pi]

[signal hemlock]

i dont know if im restricted or not but i realized when i took sqrt of both sides initially i got 2 extra solutions

without double angle formula

[humble pulsar]

but with square root, you get an angle in all 4 quadrants

since you have the 2 cases where it's neg (quad 2, 3) and 2 where it's pos (1 and 4)

[signal hemlock]

yeah

so how do i make sure this mistake never happens again

make sure never to use double angle formula? xD

@humble pulsar

always prefer sqrt solutions over double angle formulas or?

[humble pulsar]

I think prefer sqrt or get it in terms of x not 2x

I dont know the exact reason sorry lol

[signal hemlock]

maybe someone other can have a look

<@&286206848099549185>

somnone who can explain what im doing wrong?

[lime hawk]

im so confused

[signal hemlock]

ill help you if you can get some help for me

[lime hawk]

ill help you if you can get some help for me
@signal hemlock sir i have no clue what your problem is even asking

[signal hemlock]

so

which angle did u start with?

[lime hawk]

wha

oh

[signal hemlock]

number 5?

[lime hawk]

i was given 40° and 125° so i did 5

bc that one was easy

[signal hemlock]

yeah and 5 is?

[lime hawk]

55°

[signal hemlock]

yeah

and then u did?

[lime hawk]

im not sure which to do next

[signal hemlock]

have u tried extending the lines of that triangle?

outside of those 2 parallell lines

so make it really clear visually

whats going on

[lime hawk]

wha-

im so slow

[signal hemlock]

ill draw for you

[lime hawk]

;-;

ok tyy

[signal hemlock]

https://i.imgur.com/M5Y1eaC.png

so

if you extend it like this

[lime hawk]

ohhhh

[signal hemlock]

do you understand/see the symmetri?

[lime hawk]

the angels of the triangle arent congruent though

[signal hemlock]

are the lines not parallell?

you dont need a congruent triangle

do you see how that angle below 3 is the same as the 40deg angle?

that makes the 3 to be 180-40

that means you aslso get 4 for free

[lime hawk]

ohhhh

wait ok that makes sense

[signal hemlock]

now you see why we extended the lines

it was just to make it clear

[lime hawk]

yess

[signal hemlock]

that those angles are actually the same

[lime hawk]

yeah i see that now thank youu

[signal hemlock]

np

[teal mica]

Hello, can anyone help me figure out the steps to solving this:

I understand the points for special angles like arcsin(1/2) or arccos(-rad3/2), but this one i'm having trouble with

[humble pulsar]

$\acot{x} = \frac{1}{\atan{x}}$

[somber coyote]

moshill1:

[humble pulsar]

@teal mica ^

[knotty matrix]

yall, i need help!

if i want to make a 4 ft tall Regular icosahedron, (D20), how large should I make each face of the dice?

[high geode]

anybody know how I can solve number 11 and 12? I'm kinda stuck on these

[teal veldt]

Hey I need some help with geometry I havent done this in 2 years and were doing a review and to be completely honest with you im lost

This is SSS and SAS and AAA right?

[silent plank]

@high geode compound angle identity

@Swifyz#6447 where are you getting SAS and AAA?

[teal mica]

Anyone mind explaining how they got the given angles from sin theta = -1/2 using algebra w/o graphing?

I understand it when I graph it, but don't understand how to evaluate it

[silent plank]

general solution for sine

[umbral snow]

It's a memorized result

Know your unit circle!

[silent plank]

$\sin(\theta) = -\frac12 \
\theta = n\pi + (-1)^n \arcsin(-\frac12)$

[somber coyote]

ramonov:

[silent plank]

(where n is an integer)

and sub in appropriate values to generate the solutions in the specified interval

(or apply properties of the unit circle without this)

(calculations are effectively the same)

[civic fiber]

help anyone

[upper karma]

since pr bisect ts, we have
tq = qs and pq = qr

pr and ts is a streight line, we have angle pqt = angle sqr

we use SAS congruence

[upper karma]

Can someone help me out with vectors?

[upper karma]

so, you add the vector tip-to-tail

for example

$\vec{u} + \vec{v}$ is equal to connecting $\vec{u}$ tip to the tail of $\vec{v}$

[somber coyote]

DrifAssault:

[upper karma]

@upper karma any more questions?

here is the visuals

$\vec{u} + \vec{v}$ is equal to connecting $\vec{u}$ tip to the tail of $\vec{v}$
@upper karma HUH?

so

look at the visual

okay

or if you have time, you can try watch 3blue1brown linear algebra series if you want like a video to guide it

how to do the other ones?

well, do you know scaling vectors?

basically, $-\vec{w}$ is the same as -1 * $\vec{w}$

[somber coyote]

DrifAssault:

[upper karma]

which in this case, you flip the vector backward

[dim flicker]

help anyone?

[humble pulsar]

Oh yeah i can help with that question you posted @dim flicker

[dim flicker]

ooops

https://cdn.discordapp.com/attachments/464136439685447712/770318992672948274/unknown.png

it's been answerd

answered *

but i want to make sure it's 100% correct

@humble pulsar

[humble pulsar]

if it's already been answered then it's done lol

[dim flicker]

ok

do you think you can help me

with

6 more

[upper karma]

https://cdn.discordapp.com/attachments/763610213017845800/763610565083660308/unknown.png

can someone help me understand wt to do

[upper karma]

@dim flicker

Jesus, 6 more? 😆

oh, wait

says "nearest tenth"

@dim flicker

[upper karma]

@silent hollow a) can't be 0.430

[silent hollow]

what?

it is

its was some radians shit

[elfin agate]

no i dont

Im billys mate

i did it for him

you wrong dspider

[upper karma]

did you use the law of sines?

[elfin agate]

no

[silent hollow]

@upper karma i appreciate the effort tho

[elfin agate]

area = 1/2 absinC

its in radians btw

[upper karma]

where did I go wrong in my calculation?

[elfin agate]

i dont realy get what youve done

the sine rule isnt needed at all

it just says show that theta = 0.430

[humble pulsar]

@upper karma $\sin{\theta} = \frac{h}{8} \implies h=8\sin{\theta}$

[somber coyote]

moshill1:

[humble pulsar]

But your answer assumed theta was .43, which is wrong to do

[upper karma]

yes, that's what a) wants

to prove that 0.430 is correct

[humble pulsar]

Yes

[elfin agate]

It says the area is 20cm^2

[upper karma]

and it's not

[humble pulsar]

you messed up the calculation

[elfin agate]

and it is 0.430 radians

[upper karma]

hence why I used pi/2 instead of 90 degrees

[humble pulsar]

You cant assume the thing you're trying to prove/show is true. . .

that's the biggest flaw

[elfin agate]

you are overcomplicating it

[upper karma]

well, I found the height of the triangle, and the area doesn't equal 20 cm^2

[elfin agate]

Its just 20 = 1/2absin(theta)

[humble pulsar]

@upper karma you didnt find the height correctly

[elfin agate]

20 = 8 x 12 x sin(theta)

[humble pulsar]

Even assuming your attempt at a proof is correct, you still messed up finding h

[upper karma]

you mean 1/2 ab(sinC)

and you don't know C

[humble pulsar]

yes

you know area, a and b

hence you can find C

[upper karma]

you have to use the law of cosines to find C

[humble pulsar]

no

you use trig area formula

[elfin agate]

arcsine(20/48) = 0.430

thats literally the only calculations

[humble pulsar]

Even if you didnt know the trig area formula, you could find h and then find theta

[upper karma]

I did find h

[humble pulsar]

You didnt

[upper karma]

it's 6.88/pi

[humble pulsar]

you did it wrong

i cant say it anymore clearly

$A = \frac{bh}{2 } \implies h = \frac{2A}{b} = 10/3$

[somber coyote]

moshill1:

[elfin agate]

why are you trying to find the height of the triangle?

it doesnt ask for that

[humble pulsar]

$\sin{\theta} = h/8 \implies \theta = \asin{\frac{h}{8}} \approx 0.430$

[somber coyote]

moshill1:

[humble pulsar]

@elfin agate multiple ways to skin a cat

[elfin agate]

just use A = 1/2 ab sinC

[humble pulsar]

If you didnt know A = 0.5absin(theta) how would you solve the question

[elfin agate]

its by far the simplist

[humble pulsar]

answer me that please

[elfin agate]

i wouldnt

[humble pulsar]

exactly

[elfin agate]

but i wouldnt ask dspider

[humble pulsar]

You can find theta without that formula

and I wouldnt ask you for help

[valid jacinth]

N6

1. Find the coordinates of points A, B, C, D, E and F.
2. The Point G has the same abscissa as A and the same ordinate as D.
   N5
   Find the coordinates of G. Then place G on the mark.
   Give the coordinates of points A, B, C, D and E.

Can someone explain what i'm supposed to do I translated from English to french

[humble pulsar]

@valid jacinth what part are you confused about exactly?

[valid jacinth]

All of it i really don't get it just the basics would be enough

[humble pulsar]

ok so a co-ordinate is made of 2 parts (x, y)

[valid jacinth]

alright continue explaining Im just writing it down

[humble pulsar]

the x (abscicca) tells you where you are horizontally (left to right)

the y (ordinate) tells you where you are vertically (up and down)

(0,0) we call the origin; everything left and down have negative abscissa/ordinate. everything right and up have positive

[valid jacinth]

so 0,0 is like the middle part?

[humble pulsar]

yeah

it's the big O in the middle of the grid

[valid jacinth]

alright now how do i measure it do i just count the horizontal and vertical lines from the origin to the point im supposed to measure (sorry if my english is bad)

Hello?

[humble pulsar]

Yeah you go based on the markings

[valid jacinth]

Alright thanks man/woman

[upper karma]

@silent hollow @elfin agate @humble pulsar

I still don't think a) is correct

[humble pulsar]

you're still using law of sines for right angle trig

[silent hollow]

i aint gonna lie bro i dont have a clue

i looked at the mark scheme and u dont have to do that

[humble pulsar]

OH you're not doing law of sines right in the first place @upper karma

$\frac{\sin{A}}{a} = \frac{\sin{B}}{b}$

[somber coyote]

moshill1:

[upper karma]

d'oh

https://tenor.com/view/homer-simpson-homer-disappears-bush-hiding-gif-3377649

I'm sorry, guys 😦

[silent hollow]

no worries pal

thanks anyway

[humble pulsar]

You had the right idea

[elfin agate]

https://tenor.com/view/lebron-james-nba-finally-about-damn-time-gif-4019567

[odd lotus]

muppet

[civic fiber]

can someone help me out with this problem

[flat viper]

Cos theorem doesn't workkk

Sorryy language is not English but it's easy to understand

[upper karma]

Hi, I need a problem book that will get me from zero to hero in classic geometry
I barely know what is central and inscribed angle
Here is what the book(s) should cover: congruence (of triangles), similarity (of triangles), construction problems, inversion, isometric transformations of a plane, stereometry, and isometric transformations of space
It's a 2nd year uni course

[stray thorn]

I’d recommend geometry for dummies

[novel ginkgo]

https://screenshot.alphexus.com/7R1dcDDywE.png

Hey can someone help me with 2.

I don't know if 1 is right either.

But I think so because vertical angles.

[humble pulsar]

@upper karma what do you mean manually?

Like what question are you trying to solve?

[obtuse hornet]

How does one going about solving this in the simplest way

[silent plank]

exterior angle theorem

[obtuse hornet]

Confused on how to do the first one. Second one, I understand but does anyone know the name for the theorems and stuff for the proof?

[magic wasp]

Can anyone answer my trig question

[silent plank]

first one, they asking you to prove the exterior angle theorem which can be done by applying angle sum of triangle and angle sum on a line

[magic wasp]

like if im looking for a side length of a right angle I can use SOH CAH TOA, but I need at least 1 angle and 1 other side right?

or 2 angles and 2 sides

but with 2 sides I could use the Phyth theoren

m*

[silent plank]

2nd one, look up properties of parallel lines.
angle sums/vertical angles is also used

1 additional side and angle is enough if you are given its a right triangle

or 2 sides

what's the issue you're having?

[vapid pendant]

Anyone good with geometry?

[obtuse hornet]

first one, they asking you to prove the exterior angle theorem which can be done by applying angle sum of triangle and angle sum on a line
@silent plank So what would you write to prove it?

[silent plank]

@obtuse hornet
applying angle sum of triangle: < 3 = ?
applying angle sum on a line: < 3 = ?
hence ...

[obtuse hornet]

I think i might just be dumb cause I still dont understand

[silent plank]

you are referring to problem 8 right?

[obtuse hornet]

Yeah.

[silent plank]

whoops bad labelling

@obtuse hornet
applying angle sum of triangle: < ABC = ?
applying angle sum on a line: < ABC = ?
hence ...

[obtuse hornet]

uhhh

I'm hella lost lol.

[silent plank]

are you familiar with the 3 point labelling system for angles?

[obtuse hornet]

Yeah

you mean like CAB and ACB?

[silent plank]

yes

what are the 3 angles in your triangle?

[obtuse hornet]

CAB, ABC, BCA?

[silent plank]

yes,

what would be their sum?

[obtuse hornet]

uh

[silent plank]

angle sum of a triangle is: ?

[magic wasp]

Im doin trig so if anyone needs to ask a q im up for the task

[obtuse hornet]

180

[silent plank]

yes

<CAB + <ABC + <BCA = 180°
hence <ABC = ?

actually don't actually need to go through that step

now consider the line CBX

what are the angles on that line?

[obtuse hornet]

ABC and CAB

[silent plank]

no

<CAB isn't on that line

[obtuse hornet]

wait wat

How isnt it tho

o wait ABX?

[silent plank]

yes

and what would be the angle sum of <ABC and <ABX?

[obtuse hornet]

180

[silent plank]

yes

since their sums are both 180°
<CAB + <ABC + <BCA = <ABC + <ABX
then subtract <ABC from both sides

note that <BCA and <ACB refer to the same angle

[obtuse hornet]

Ahhhhh i get it now

Thank you for the step by step explanation

[silent plank]

also i couldn't be bothered with the m for measure

[obtuse hornet]

Do you know the properties for problem 9? I think i understand but im . not good with the names of these theorems and properties...

[icy wyvern]

how would you prove that two circles intersect?

[upper karma]

Can someone help me write a proof? I need to show how a model of a chair and the actual chair are similar. The scale factor from chair to model is 1/4, and I can give measurements for the chair/model as well

[open onyx]

Yea I got you

[upper karma]

<@&286206848099549185>

[wet mural]

if anybody needs help with geometry i can help

[red oxide]

hey @wet mural its p stupid but idk

[white swift]

whats that m doing there :'o

[silk patio]

m just means measure

[red oxide]

ive tried doing 3n+1 = 110 but that results 36.5 and ive tried 4n+4 = 110 and that is 26.5 but nun of that adds to 110

[silk patio]

Look at the picture Ian

The 110 is both of the angles combined

[white swift]

can you not do (3n+1) + (4n + 4) = 110 😅

[red oxide]

i need to find SDT and TDI

[silk patio]

They have given you that

And they add to 110

[white swift]

7n + 5 = 110
7n = 105
n = 15 etc
...

[red oxide]

wha now im confused 😅

[white swift]

what's confusing

[red oxide]

because euler said they add to 110 but wouldnt that just be (3n+1) + (4n + 4) which = 110?

[white swift]

yes

[red oxide]

why wouldn't doing (3n+1) = 110 find me SDT then?

[white swift]

and 3n + 4n is 7n and 1+4 is 5

(3n+1) = 110 - TDI

what you wrote there isnt correct

as 110 = both angles

110 = TDI + STD

[red oxide]

oh ok how would i find it for each angle then

[white swift]

so you could end up writing 3n+1=110-(4n+4)
but that's really just a long way of writing
7n+5=110

you solve for n

and then you substitute back n to find the angles

STD = 3n + 1
TDI = 4n + 1

do you understand it

[red oxide]

STD = 46
TDI = 61

i think

wait

ohhhhh

ok im stupid

[white swift]

you got STD correct

[red oxide]

yeah i meant 64

so basically i just forgot to substitute n back in

thanks : )

[wet mural]

7n + 5 = 110
7n = 105
n = 15 etc
...
@white swift thats correct

[upper karma]

I already solved this but I need someone to do it and see if they get the same answer as me

Bc I’m not rlly sure if I did it right

[dark sparrow]

can you show your answers first

[upper karma]

Yeah sure

I got x=6

And y=-3

@dark sparrow

[dark sparrow]

that doesn't seem to match up with my answer of x=18 and y=9.
and it also makes angle 3 have a negative measure, which is really sus.

[upper karma]

Yeahh

[dark sparrow]

wait

[upper karma]

I think I did my equations wrong

[dark sparrow]

i typo'd when copying the problem statement down

[upper karma]

Ohhh ok

[dark sparrow]

though this gives even uglier values for x and y.

[upper karma]

Lol

Does that mean u did it wrong

Bc of the typo

I think my equations r wrong, I’m not rlly the best at making equations

[dark sparrow]

y = 45/13 and x = 90/13 is the new answer i'm getting.

[upper karma]

Oh fractions

[dark sparrow]

which is much weirder

[upper karma]

Great

Ikr

When it’s a negative or a fraction I feel like it’s wrong

[dark sparrow]

those are different kinds of wrong

[upper karma]

I’ll tell u my equations

[dark sparrow]

if an angle comes out negative you know for sure it's wrong.

ditto for a length or area.

[upper karma]

7x-y=45 and -3x-6y=0

Yeah

[dark sparrow]

first one is correct, second one looks wrong

[upper karma]

I agree with that

[dark sparrow]

i got x=2y as my second

[upper karma]

Howww lol

What angles did u use

[dark sparrow]

(x+y) + (5x+7y) = (3x+9y) + (2x+y) is one of the ways to express it.

x = 2y happens after simplification.

[upper karma]

Ohhhh that’s a good way

Thanks I learned something new

Lol

I’ll solve for x and y now

And see what I get

It’s a fraction

R we supposed to get a fraction lol

[proven herald]

WIll pay someone whos good at trig $10 to answer (not explain) a few trig Q's for me

[junior light]

#changelog

[sick ember]

can any one help me with this i am new to geo

[upper karma]

you know you can google those terms, right?

[upper karma]

test ?

aight

exterior angle theorem

do you know it?

[upper karma]

this is correct?

[upper karma]

can some1 help me rq

[upper karma]

<@&286206848099549185>

anyone ?

[hollow raven]

@upper karma this might help

The key thing to note here is

x, or the height of the house, is constant

so using two trig ratios, both having some relation to x, you can isolate each ratio for x.

And since these two ratios are = x, they will also be equal to each other

you can use this to solve for y

Ignore my ugly pineapple lol

Let me know if you want any more pointers

[upper karma]

ahh thanks

so how do I find how far Patrick and squidward are from the BASE

is it just 50 for Patrick and y for squidward

@hollow raven

if they're equal then would it be 100 for Patrick and 50 for squid?

also what's the two things on the right that u used for the height

[hollow raven]

for patrick its 50 + y

for squidward its y

50 + y because squidwards distance is y, and patrick is 50 away from squidward

Patrick: tan(49) = x/(50+y)
Squidward: tan(61) = x/y
x = (50+y)tan(49)
x = ytan(61)
(50+y)tan(49) = ytan(61)

Just solve for y and you get squidwards distance, and get that value and add 50 and you get patricks distance

[ashen trail]

help?

[tired terrace]

yeah i can help @ashen trail

[ashen trail]

oh really? thanks

[tired terrace]

How we can do this, is in the given, PT is a bisector

which means, that it splits VTU into 2 equal triangles

which means angle 1 is the corresponding angle in triangle 2, which means theyre the same thing

[ashen trail]

Yes and m<1 is congruent to m<2

yup

[tired terrace]

right

so, we can set up the equation of

$m1 = 7x + 2 = 16x + 4 = m2$

[somber coyote]

Cinnamon:

[tired terrace]

which means

$7x + 2 = 16x +4$

[somber coyote]

Cinnamon:

[tired terrace]

solve for x, and then plug it back in

[ashen trail]

Is it not 7x + 7?

[tired terrace]

mb it is

[ashen trail]

Ok, so 7x+7 = 16x+4

[tired terrace]

which tells us that x = 1/3

which means that 16(1/3) + 4 is the answer

and you can check it by putting it into the other one

it should give the same thing

yes it can.

[ashen trail]

ok

[tired terrace]

it ends up being 9 1/3 or something

[ashen trail]

28/3

yeah

okay, thank you.

[tired terrace]

Thats the answer, and you could solve the rest if you wanted to knowing angle p = 90

but

im a geo tutor in the highschool

i think

theres no logical reason behind why it cant be a fraction

unless you see something I dont

anywayssss

I need help with my problem now

i have no clue on where to start here

[ashen trail]

oh

I'm only a freshman

[tired terrace]

im a junor

junior*

[novel berry]

This looks like help angel method problem 😄

[ashen trail]

Um, what?

Can someone ban him please?

[hexed birch]

Done.

[neat sigil]

Thank you

sir

[mossy valve]

what does the arrow mean