#geometry-and-trigonometry

1 messages · Page 83 of 1

trail tendon
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doesn't look solveable with elementary functions

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no those are not the same for all theta

faint pasture
trail tendon
faint pasture
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Ig youre given the first result and you have to show the second one

faint pasture
trail tendon
faint pasture
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,w sinx + cosx = sqrt(2) sinx

somber coyoteBOT
faint pasture
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,w sec(3pi/8)

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,w 2 sqrt(2) sin(3pi/8)

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Looks like it does

faint pasture
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It is true

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Idk how youd arrive at that

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But its true

earnest musk
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Bro is this the answer to my question?

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Never seen anything like this lol

trail tendon
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huh?

faint pasture
faint pasture
# trail tendon huh?

Unless wolframs tripping hard then yea it does follow from that one way or the other

trail tendon
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cos(theta)+sin(theta) = sqrt(2) sin(theta)
cos(theta) = (sqrt(2)-1) sin(theta)

sec(theta) = (sqrt(2) + 1) sin(theta)
sec(theta) = 2sqrt(2) sin(theta)

(sqrt(2)+1) sin(theta) = 2sqrt(2) sin(theta)
sqrt(2) + 1 = 2sqrt(2)
sqrt(2) = 1

sully

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um

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ignore me

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LOL

faint pasture
trail tendon
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yea opencry

faint pasture
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Mmm

trail tendon
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but then

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csc^2(theta) = 2sqrt(2)/( sqrt(2)+1) ?

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sin^2(theta) i mean

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bro im trippy rn LOL

faint pasture
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Mahn what are we even doing just weirstrass the first eqn thats given to us

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And then get tan(theta/2)

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And use that to prove the second eqn

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Idk the elementary method

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But this works

faint pasture
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Actually no

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That give sin theta>1

faint pasture
trail tendon
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i was?

faint pasture
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Yea

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😭 were you

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Idk

trail tendon
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no 😭

faint pasture
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Listen just apply the weirstrass and its easy

earnest musk
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Ended up in it the same place

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Just took less time then last time

faint pasture
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And same for cos(x)

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Then solve

trail tendon
earnest musk
earnest musk
trail tendon
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i'm not getting anywhere bleak

earnest musk
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I think there might have been a mistake no way they gon give us this hard stuff I'm in secondary school

faint pasture
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Obv

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Like jjst by algebra i meant

trail tendon
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boutta throw hands

earnest musk
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lol I though this was easy at first bout to start crying now

faint pasture
earnest musk
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Is it even possible with the restricted tools I have?

faint pasture
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Id be suprised if it even was

dire mirage
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May I ask for assistance on this particular problem?

earnest musk
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I think Using 3 perpendicular mirrors a light ray with an incident angle of 55° reflects back in the opposite direction, keeping the final incident and reflected angles at 55°.

faint pasture
faint pasture
# dire mirage

The que is ambiguous tho? Does it want us to give it the total number of mirrors (including the original one) or just how many extras we used

earnest musk
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I did it guys (I think) can you see if it's correct and I know I have horrendous handwriting

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@faint pasture

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@trail tendon

faint pasture
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It is all correct from what i can see

earnest musk
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Aight thanks for the help

obsidian rock
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Why is it sin A?

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(unit circle)

obsidian harness
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use the circle theorem that the angle at the centre is 2A

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then split the isosceles triangle into two congruent right triangles

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you get $2R \sin A$

somber coyoteBOT
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south, just south

obsidian harness
obsidian rock
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Wouldn't this mean that, since r in unit circle is 1, then a = 2sinA?

upper echo
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yep, it is simple just write the left side as sin(pi/2-t)+sin(t) and use sum of sines.

dreamy vessel
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Suppose a cube has side lengths of a. What is the area of the region of points that are closer to the center than any one of the vertices?

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This problem got a crazy solution and it was in an anime

upper karma
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assination classroom ?😏

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lmao i got the spelling wrong

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assassination

upper echo
dreamy vessel
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Not quite

upper echo
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why not?

dreamy vessel
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The mid points of those lines are good but it's not an octahedron and there's a much more elegant way

upper echo
dreamy vessel
upper echo
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for some reason you have taken only those points which are inside the cube

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so, yes, if you cut out only the part inside the cube you will get the solid on you figure

dreamy vessel
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Oh man

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That's my fault it was supposed to be strictly inside the cube

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Whoops

upper echo
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never mind. the problem and its solution is clear to me.

dreamy vessel
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Like making more points around the cube?

upper echo
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I mean, an equation of the midplane is easy: you take a vector from center to vertex: say (1,1,1) and you immediately get an equation (x-1/2)+(y-1/2)+(z-1/2)=0 And the same with two more non-parallel planes. So, we solve a system of 3 linear equations and find coordinates of just one vertice in that octahedron. The rest is easy because of symmetry.

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And for cube centered at O with vertices like (1,1,1), (1,-1,1) we get vertices of the octahedron like (3/2, 0, 0). Just exactly as seen in the figure. So the side of the triangle is 3a/sqrt(8).

dreamy vessel
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https://www.youtube.com/watch?v=64ZjFXrFBqE&t=161s&ab_channel=Phanimations Skip to 1:15 for the problem and from there watch and you'll see two solutions. One of them is basically bash, and the other one is the one

This is a stupid little scene I've had stuck in my head for years, so for anyone who watched it and was completely confused here ya go! Or, if you haven't seen Assasination Classroom, go watch it!

Music
NCS Chill Music
Free Chill Lo-Fi Music (For YouTube Videos) - "Colorful Flowers" by @tokyowalker4038 🇯🇵

Mata Kimi Ni Aeru Hi (Assassination Cl...

▶ Play video
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That's not very nice

vital rain
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Yes

dreamy vessel
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YOu can't whip this devious stuff out

vital rain
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My bad let me put that back in

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Can you do me a small favour tho

dreamy vessel
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What is it

vital rain
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Could you solve my homework

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It has a weird name

dreamy vessel
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Send a picture and then I will decide

vital rain
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Birch and Swinnerton-Dyer Conjecture

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Is that sweedish

dreamy vessel
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oh hell no

vital rain
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Pretty please

dreamy vessel
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I'm a freshman rn

vital rain
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Good enough

trail tendon
dreamy vessel
trail tendon
trail tendon
upper karma
trail tendon
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no, could never be

vital rain
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I solved it

dreamy vessel
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what you get

vital rain
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It connects

cloud sonnet
# vital rain

Sometimes I’m glad I’m in foundation maths and still in secondary school cause what is this 🤣

upper karma
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Lol

cloud sonnet
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It’s hardly even maths it’s just pure letters 🤣

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I know they have values but still

vital rain
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Yh I just made that up lol

cloud sonnet
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Oh aha

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So annoying that we don’t even learn what sin cos and tan is

vital rain
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You do

cloud sonnet
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We was told that we don’t need to learn it for our exams even though the last question was what is sin 30

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Only higher tier does that

vital rain
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Is it non calc?

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There is an easy way to do it tho

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You just need to remember sin that's it

dreamy vessel
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1/sqrt2 is bad

vital rain
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Hush

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Root2/2 same thing

dreamy vessel
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that's better

vital rain
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I picked the 1st one I saw

dreamy vessel
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Who ever made that

vital rain
vital rain
cloud sonnet
dreamy vessel
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petualant

vital rain
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So for sin you just remember the degrees at the top

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The put 0 1 2 3 4

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Then root them

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And divide by 2

slim vigil
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Just use a calc (slang for calculator)

vital rain
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Cos is the opposite of sin

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And tan is sin/cos

vital rain
cloud sonnet
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Yeah my maths calc is tmr

slim vigil
vital rain
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Uh

cloud sonnet
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We have 1 non calc and 2 calc

vital rain
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Oh you do gcse

cloud sonnet
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Yeah

vital rain
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I did that a year ago it was pretty calm

cloud sonnet
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Ahh yeah I’m assuming u did higher then aha

vital rain
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I kinda flopped didn't get the grades I wanted

cloud sonnet
vital rain
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8

cloud sonnet
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That’s really good

vital rain
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Eh

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Wanted a 9

cloud sonnet
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Only 1 grade off

vital rain
cloud sonnet
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Idk tbh I’m just watching maths revision videos

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Mostly on simultaneous equations

vital rain
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The thing is if you revise just before you sleep you won't remember much

vital rain
cloud sonnet
cloud sonnet
vital rain
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Better thing to do is sleep early and wake up at like 2 or 3 and revise

cloud sonnet
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Oh damn

vital rain
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I got like 3 or 4 hours average sleep during my gcse lol

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Had to revise last minute

cloud sonnet
vital rain
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Start you revision Like a month or two before the test and you are set

cloud sonnet
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Yeah I did kinda do that but I’ve been revising mostly stuff I already know like Pythagoras and angles and stuff

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Stupid move

vital rain
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Yh

cloud sonnet
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So what do u do at college

vital rain
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Is college a levels?

cloud sonnet
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Yeah

vital rain
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Ah

cloud sonnet
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Well

vital rain
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I do maths furthermaths Chem and physics

cloud sonnet
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Yeah loads of different routes to take at college but A levels are the main ones

cloud sonnet
vital rain
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5 hours sleep lol

cloud sonnet
vital rain
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Mostly cause I leave my homework until the last day

cloud sonnet
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I always do that

vital rain
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I wake up at 5 normally arrive to school at like 7.30

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If I have homework mabye I wake up at 3-4

cloud sonnet
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Bro just do it through the day 😭

vital rain
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Yh I do some at school

cloud sonnet
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Fair enough

vital rain
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Our school has like study peroids instead of free peroids

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So you can like do homework/revise

cloud sonnet
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Period 7s

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Absolute pain

vital rain
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Bro what

cloud sonnet
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It sounds stupid

vital rain
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When is that 530

cloud sonnet
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Basically it’s another lesson and you revise for exams and stuff

cloud sonnet
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My school starts at 8:20

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We typically leave school at 2:45

vital rain
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Oh we leave at 3

cloud sonnet
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And then for year 11s like myself if we have period 7s they are between half an hour to 50 minutes depending on the teacher

vital rain
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Mist I had was peroid 6 during gcse

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Most*

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People who didn't meet their target had to go for a 7th one

cloud sonnet
vital rain
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Peroid 6 was an hour

cloud sonnet
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My period 6 used to be an hour

vital rain
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Oh ok

cloud sonnet
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Well at my school it’s 50 minutes

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And period 5 for some reason is 1 hour

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Don’t ask why even I don’t know 🤣

vital rain
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We also had Saturday classes

cloud sonnet
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Bro did u go my school 🤣

vital rain
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Can't lie they did not help

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I just went for the sake of it

vital rain
cloud sonnet
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Fair enough I might go this Saturday

cloud sonnet
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In this context

vital rain
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Oh

cloud sonnet
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Ngl foundation maths has ruined me in what I can do

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I wanna do engineering

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I can do it but I won’t be able to a uni

vital rain
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My friend moved up from foundation like a few months before the test

cloud sonnet
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That’s what I’m trying to aim for

vital rain
cloud sonnet
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I’m getting a maths tutor and everything lol

vital rain
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Mostly a levels and stuff

cloud sonnet
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Wait what

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Seriously

vital rain
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Yh...

cloud sonnet
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Stupid question I know aha but I thought it cause u need good GCSEs to get into certain A levels

vital rain
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They like gaslight you too much at gcse

cloud sonnet
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Fair enough

vital rain
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If you get 6+ you are set

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7+ grades even better

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I would show you my gcse certificate if I had them rn I just got them earlier today

cloud sonnet
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Yeah with foundation I can’t cause max u can get is a 5 and the grade boundaries for edexcel are ridiculously high

vital rain
cloud sonnet
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Fair enough

vital rain
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I can tell you off the top of my head what I got if u like

cloud sonnet
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Can do

vital rain
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My grades aren't like crazy

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I got 6 for physics, bio, French, business, both English

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I got 7 in chem

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I got 8 in maths, furthermaths , re and geography

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That's it I think

cloud sonnet
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Why do u do so many GCSEs

vital rain
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I did triple science

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So I got 3 science grades instead of 2

cloud sonnet
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Ahh

vital rain
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And furthermaths was optional

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Ngl it was way easier than the actual maths higher last year

cloud sonnet
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how 🤣

vital rain
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The test I mean

cloud sonnet
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Ah

vital rain
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It easy too

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You should look at a past paper they are doable after you learn a few things

cloud sonnet
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For someone who got a grade 8 it probably was easy

cloud sonnet
vital rain
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Eh I only revised for it the day before the test

cloud sonnet
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Yeah what I normally do is I watch a video of a guy explaining it and if I don’t get a topic I try and rewatch if not I got on for example maths genie or dr frost and find the type of questions I don’t get from the exam and attempt them

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I did that today and I did meh

vital rain
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Mabye lives streams may help

cloud sonnet
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Yeah I’ve been watching some on TikTok

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It’s crazy I’ve been revising purely maths for the mocks aha

vital rain
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Ah ok

vital rain
cloud sonnet
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Yeah it isn’t

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Atleast these are only practice exams

vital rain
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What subjects do u d

vital rain
cloud sonnet
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I do history Re stats and engineering

cloud sonnet
vital rain
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English?

cloud sonnet
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Yeah I do the usual 3

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Maths English and science

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Science it’s combined

vital rain
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Oh I also somehow got destination for that gcse speaking thing

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I just waffled

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I thought I was getting a merit

cloud sonnet
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Ahah

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ima go sleep now I’m shattered

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Night mate

vital rain
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K good night

narrow crescent
#

the question:
Write the corresponding triangle congruence theorem (SSS, SAS, ASA, AAS) and complete the congruence statement

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i wrote " triangle STA is congruent to triangle RTA becaus eof the AAS postulate"

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she then marked my paper with

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Angle STA, and Angle RAT "Do you have 2 sides"

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basically what it looked like

exotic yarrow
narrow crescent
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wait so

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would i do

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triangle(STA) ≅ triangle(RTA) because SAS

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or angle(STA) ≅ angle(RAT)

exotic yarrow
narrow crescent
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because sas

exotic yarrow
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$\triangle STA \cong \triangle RAT$ is one way to write it

somber coyoteBOT
#

Civil Service Pigeon

exotic yarrow
#

there's 5 other ways though so catshrug

devout whale
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By reading some messages I come to conclusion, that I'm so fucked up in school

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What de hell I was thinking to go into high school

trail tendon
rich knot
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don't think this needs a whole forum post, just going to ask; Trigonometry, unit circle, yeah? am I right in thinking every point on the circle's x is the cos to that angle/y is the sin to that angle?

obsidian harness
#

yes, this is the unit circle definition

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unit circle, as in the hypotenuse has to be 1 for this to work

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otherwise it will be $(x, y) = (r \cos \theta, r \sin \theta)$

rich knot
#

awesome, that's all I needed

somber coyoteBOT
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south, just south

obsidian harness
#

np!

hidden willow
#

hii ive got a question

obsidian harness
# hidden willow

ah so let s = side length of the red square
since the side length of the squares that make up the cross = 1

hidden willow
#

ye but i dont know where to go from there

obsidian harness
#

then by Pythagoras we observe $s = \sqrt{3^2 + 1^2} = \sqrt{10}$ hmmm

somber coyoteBOT
#

southlander!

obsidian harness
#

ah so that must mean that we have a pair of similar right triangles

hidden willow
#

hmmm

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where do we go from there

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?

obsidian harness
#

these 2

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so comparing side lengths we have:

$1, 3, \sqrt{10}$

$?, 1, ?$

somber coyoteBOT
#

southlander!

obsidian harness
#

it follows that the short side = 1/3

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and the hypotenuse of the small triangle = sqrt(10)/3

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this is enough information to find the perimeter of the blue pieces

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also note that 1 - short side = 1 - 1/3 = 2/3 appears multiple times

hidden willow
#

So we got that this length is 1/3

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?

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is this it

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and then

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1/3×12 + 4/3

obsidian harness
#

the squares have side length 1

hidden willow
#

oh yeah wait nvm

obsidian harness
#

also I see 4 * sqrt(10)/3 in there

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since it's the perimeter not the area I think you can't join up the three pieces btw

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that works for the area ofc

hidden willow
#

ill have a look again tysmmm

obsidian harness
#

np!!

somber coyoteBOT
#

Result:

15.549703546891
obsidian harness
#

ah so it might be easier to think about it if you join the 3 blue pieces together, which has a perimeter of 3 * 4 = 12

then you have to add on the 4 edges which each have length sqrt(10)/3

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,calc 12 + sqrt(10)/3 * 4

somber coyoteBOT
#

Result:

16.216370213558
obsidian harness
#

@hidden willow

chrome token
#

does anyone know a synthetic proof of existence of isogonal conjugates? (so no trig ceva stuff)

compact current
vital rain
obsidian harness
#

nice problem

vital rain
#

Na it's a maths challenge

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I see the question

trail tendon
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why does that look like the python symbol...

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💀

vital rain
#

Huh

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It's because there is a plus with blue and yellow

vital rain
#

Uh

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Ping the other guy I arl solved it

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Thx anyways

neon ledge
#

ok sry ill delete my message

cobalt pecan
#

guys rate these questions

obsidian harness
#

$\sec^2 \theta - \tan^2 \theta = 1 \implies \sec \theta + \tan \theta = 1/x$

somber coyoteBOT
#

southlander!

obsidian harness
#

should be clear what to do from here

cobalt pecan
#

This is wht i did

obsidian harness
#

yeah I think the other question with tan and sin is harder

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since it gives you a choice I'd just do the easier question, haha

cobalt pecan
#

yea fr

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This is wht I did for or

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Question

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which grade question u guess it would be?

obsidian harness
cobalt pecan
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its 10

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cbse

obsidian harness
#

ah nice

cobalt pecan
#

you are which level?

obsidian harness
cobalt pecan
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oh damn

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which one

obsidian harness
#

oh I can't say but I study in Australia

cobalt pecan
#

nice

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which course u took?

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im planning to take engineering

obsidian harness
cobalt pecan
#

but that itself is a vast field

cobalt pecan
#

so u studied in australian curriculum?

obsidian harness
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yeah

cobalt pecan
#

nice

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CBSE is rough

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purely theoretical till 10th

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like actually

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i can't do a hydrogen pop test

obsidian harness
#

oh lmao sciences

cobalt pecan
#

or study refractio thru glass prism

cobalt pecan
obsidian harness
#

ah right

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I heard they removed the periodic table from 10th.......

cobalt pecan
#

so we have to study science math and sst all the way till 10th

cobalt pecan
#

periodic classification of elements

obsidian harness
#

yeah RIP

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that's embarassing

cobalt pecan
#

in a way its good

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but also bad

obsidian harness
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cause now they'll shove all the info into 11th instead

cobalt pecan
#

yeaa

obsidian harness
#

so I think making 9th and 10th a bit more rigorous is good

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if it makes 11th and 12th more manageable

cobalt pecan
#

actually it is rigourous enough

obsidian harness
#

true

cobalt pecan
#

we have board in like 2 months 😭

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*boards

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bcs this i didnt open discord for a year

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like discord is literally dying

tawdry arrow
#

I had a trig test yesterday… I studied heavily the week prior but when I got to the big questions I blanked on part of the formula

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Tan ( x) side/side

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Forgot what x was and where to find it

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Teach said there would be a retake but I dunno how the scoring will work. Hopefully I can raise my grade

pale orbit
maiden notch
#

when you realize math gets easier and easier

trail tendon
limpid tapir
#

Like quantum mathematics as an example

trail tendon
limpid tapir
#

Quantum mechanics is physics

trail tendon
#

oh i thought you said mechanics LOL

obsidian frost
#

Prove That A F > D B
Btw F is the one in the red circle

merry knot
#

Split AF into FS and AS

keen lake
#

are there anything else?

maiden notch
#

when you draw that line it gets proven, since in a right triangle the longest line is always hypotenuse

faint pasture
#

is 3pi/2 considered a solution for tan(x) + sec(x) = 2cos(x) or no

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like desmos says yes, but undefined =/= 0 though

upper echo
faint pasture
upper echo
rich scroll
#

Find the apothem and the area of the given regular hexagon with radius of 3 cm. Draw the figure using the exact measurement of the given radius.

How do i find it with only the radius given? What i know ks the radius+ midpoint of a side= the apothem. But i only have i given PLS HELPPPP

faint pasture
#

Length + point

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Uh

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What

undone quest
#

Yo can anyone tell me how to do approach in complex problems like of advanced level

frosty rose
#

can anyone explain this formula? what is m and where does this formula come from

undone quest
#

@frosty rose It is like point slope form as far i have read

frosty rose
#

oh

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its for finding 2 tangents outside a circle connected by 1 point

undone quest
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Brung that x thing to y and u are left with m

frosty rose
undone quest
#

M is slope

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Of a linr

frosty rose
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ohh okay

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thanks brother 🫶

undone quest
#

These are various ways in which u can write an eqn for a line

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If you are new to cood

trail tendon
hybrid cosmos
#

Love it that y=x intersects the unit circle at irrational points, but when u shift it one unit to the left – it intersects only rationals

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(yes, I was lazy to do it by hand lol)

obtuse tartan
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hi guys

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i just started trig

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can anyone help me?

pulsar vale
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someone help

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pls

vital rain
# frosty rose can anyone explain this formula? what is m and where does this formula come from

There is also a quick way to find the equation from a tangent to a circle if you have the equation of the circle and the coordinates of intersection:
the lets say the equation of thr cirle is x²+y²=64
Let's say the point intersected is(a,b)
x²+y²=r² is the same as xx+yy=r²
You sub in the x and y values so the equation of the tangent would be ax+by=64

This also works if the equation is something like this (x-1)²+(y+2)²=16 and let's say the point of intersection is (c,d)
It would be (x-1)(x-1)+(y+2)(y+2)=16
you then plug in the x and y coords and you get (c-1)(x-1)+(d+2)(y+2)=16 this would be easier to expand with actual values, try it see if it works out

pulsar copper
#

can somebody explain how this is correct

soft linden
#

what all should i study for 10th grade geometry

frosty rose
brave crane
# pulsar copper can somebody explain how this is correct

You can prove that <5 + <6 = <1. The proof goes as follows:
We know that <1 + <4 = 180, so <1 = 180 - <4.
But <4 = 180 - (<5 + <6) since <4, <5, and <6 are the angles of the triangle WUV.
Now, replace <4 = 180 - (<5 + <6) in <1 = 180 - <4; this will give:
<1 = 180 - (180-(<5+<6)) = 180 - 180 + <5 + <6
Thus. <1 = <5 + <6.
Now... since <5 + <6 = <1, then both <5 and <6 must be less that <1.
Think about it in that way: 4 + 5 = 9, both 4 and 5 should be less than 9. In general, if x + y = z where x, y, and z are positive, then x and y are less than z.

upper karma
#

How do we prove the statement "If two lines are perpendicular then the product of their gradients is -1" ? i forgor

upper karma
#

but we dont know the magnitudes?

#

oh

obsidian harness
#

WLOG you have (a, b) and (kb, -ka)

upper karma
#

WLOG?

obsidian harness
#

Without loss of generality

upper karma
#

how is it (kb,-ka)?

#

dot product between what btw ?

#

south?

obsidian harness
#

Basically you want any two vectors whose dot product is 0

upper karma
#

😅 im still lost

compact trellis
#

how can i shorten these statements and reasons?

faint pasture
#

Yea

#

Like we know angle between two line is

#

arctan((m1-m2)/(1+m1m2))

#

And if this is pi/2

#

Then 1+ m1m2 = 0

#

And m1m2 =-1

#

@upper karma

upper karma
#

brb

merry knot
#

$|BC| = \sqrt{m_2^2+1},;; |AB|=\sqrt{m_1^2+1}\implies (m_1-m_2)^2=m_2^2+1+m_1^2+1$

somber coyoteBOT
#

daniel

merry knot
#

so rearranging gives the desired result

upper karma
#

back

upper karma
#

thanks!

merry knot
#

look at what i posted

upper karma
#

how can they be lengths of sides?

merry knot
#

they're the slopes of the lines

faint pasture
#

Well technically they are also the derivatives

merry knot
#

because BD is 1, AD must be m_1 in order for the slope to be m_1, same for m_2

faint pasture
#

😭 the tilted axis made it look weird

upper karma
cyan hamlet
#

Can someone solve this for me? It’s beginner physics PLEASE

a cannon ball is launched off of a 28 m cliff. it lands 22 m away and it takes 5.5 seconds. what is impact velocity with angle

merry knot
#

AB is perpendicular to BC

faint pasture
#

For vertical just use the second equation of motion

#

To get the initial vertical velocity

#

And then the first equation

#

To get the final velocity

upper karma
#

OHHHH

#

lol

cyan hamlet
#

Idk if it’s right

upper karma
#

the tilted axis did confuse me

faint pasture
random otter
#

can anyone help with me the value of k

#

,rccw

somber coyoteBOT
tawdry arrow
#

that stuff is wack

serene pond
#

Guys I'm stuck on something, can any line. intersect on any point on a line and it could be it's bisector?

#

technically if a line extends both sides infinitetly, then any point on the line could be a point of bisection right?

#

or is there some weird caveat?

trail tendon
#

I would think yes blobwg

#

i dont think theres any caveat

#

but idk

serene pond
#

so one side of tge bisector could be like 3m and the other is 4m

#

but thats just a given point in time

#

as time resumes, the lengths will change

#

but im not smart so idk

trail tendon
#

like you have a given parameterized line and a given point, and you want a function that tells you the distance from the given point to any point on the line?

#

or idk what ur tryna do

serene pond
#

well say the line extends infitely

#

but before it does

#

the given line on the sheet of paper

#

which demonstrated finite in length

#

has line that perpendicularly intersects it

#

but to the observer it doesn't bisect the finite line in half

#

so in the beginning

#

the line starts with unequal length sides

#

you know what nevermind

#

I'm thankful I got that out

#

cuz now I look poopy

#

doesn't matter if both directions have infinite length

#

any point on a line will be a point of bisection

rustic plover
#

As I was saying what math is happening here 10th grade or 11th grade

serene pond
#

highschool geometry

#

so prob 9th grade

rustic plover
#

and I assume the people doing this is middle schoolers

rustic plover
serene pond
#

well its still pre-uni

rustic plover
#

Well I did it last year too

serene pond
#

did what

#

9th grade geometry?

rustic plover
#

Pre calc and geometry

serene pond
#

oh

rain summit
#

Can anyone help me with this im lowkey lost

ornate path
#

Use pythagoras theorem

#

Since it's a square, DBC becomes a right triangle upon adding a diagonal

#

and since it's a square, the sides are equal

#

if the sides are x, then the diagonal, by pythagoras theorem will be:

#

x2 + x2 = DB2

#

2x2 = DB2

#

DB = x multiplied by square of 2

#

root of 2

#

which is in the 1st part

dire mirage
#

Pls help I've been solving for the past hour and I'm genuinely lost

ornate path
#

what do you have to find?

dire mirage
#

The area of the rectangle minus the area of the 3 circles

amber cobalt
#

Is it a square?

#

Ah yes it's a square

dire mirage
#

If it were a square I would've solved it hours ago

flint ingot
gilded forge
#

are there any formulas for calculating the area of a regular polygon with side length and number of sides given

#

cus i can't find any online

flint ingot
#

Probably not

gilded forge
#

:(

#

i'll try to find one with my friends then

flint ingot
#

If there was then they would output something if you put in 1 as the amount of sides

#

Which doesn’t make sense

#

Idk

gilded forge
#

oh we found one

#

the output is undefined with 1 side and 0 for 2 sides

random otter
#

can someone tell me the addtion part ans

upper echo
random otter
limber cliff
#

can someone do the trig part

obsidian harness
#

then use the Pythagorean identity

steel hinge
#

It is a rectangle. You can tell because the top of the bottom circle goes slightly above the bottoms of the top circles. As for finding the missing height, here's what to do. If you look carefully, you can see that if you draw lines from the center of each circle to the contact points of the other circles, you make an equilateral triangle. You can then cut the triangle in half for a right triangle to be formed, with a hypotenuse of length 2, and a short leg of length 1. You then do pythagorean theorem, to find the long legs length is sqrt(3). You also have to account for the upper radius of the top circles and the lower radius of the bottom circle. This ends up being 1+(sqrt(3))+1. This equals 2+sqrt(3), this being the height.
For the original question, you first multiply the height and width, being 4(2+sqrt(3))=8 + 4(sqrt(3))
You then subtract the area of the circles, adding up to 3pi:
8 + 4(sqrt(3)) - 3pi
That is your answer.

steel hinge
#

(I forgot to reply to the message)

#

If you're more of a visual learner, here's pictures:

steel hinge
# steel hinge

While I was able to help with this, I am currently in algebra 1, so don't expect me to help here often.

dire mirage
steel hinge
steel hinge
# rain summit

The first and last answers are correct. I will give an explanation shortly

steel hinge
#

Another easier way to prove this, is by just multiplying the sides by sqrt(2) to see if that equals the length of the diagonal

obsidian harness
#

keep it up bud

#

keep the effort and the energy up!

steel hinge
#

I am in algebra 1

#

I know a bit of trigonometry and geometry

obsidian harness
#

yeah like some people are a right mess, I'm guessing many others in your class

obsidian harness
steel hinge
#

Like how cos is adjacent over hypotenuse

#

Sin is opposite over hypotenuse

obsidian harness
#

ah yeah you do cover that in alg 1 though

steel hinge
#

I'm also pretty good with i

#

And have a full on desmos account

chrome token
#

can someone tell a nice book for synthetic geometry? (or will this go in book reccs)

smoky apex
#

can anyone teach me this

faint pasture
#

Looks like inconsistent data or not enough info

smoky apex
#

oh

#

thats all my teacher gave

faint pasture
#

Yea id say inconsistent

#

Sum of all angles in a triangle = 180

#

150+120 + angle 2 = 180

#

Angle 2 = -90 degrees

#

Which doesnt make sense

smoky apex
#

oh damn

#

okay ill try and ask for more data

dark sparrow
#

What’s the formula for area of an irregular hexagon?

merry knot
#

Extremely ugly

#

It's probably easiest to just use the shoelace formula

lyric notch
#

Chat i fucking hate trigonometrics

#

I need help with this ( em means in)

merry knot
#

i.e. the two red angles aren't the ones that are 150 and 120

faint pasture
#

Actually wait

merry knot
#

one is one side and the other is on the other

faint pasture
#

Yea it does

#

My bad

#

Still tho

#

Ambiguous

#

If you gonna mark the angle and put a value nezt to it

#

Thats not the marked angle

#

Yea thats ambiguous

merry knot
#

yes

faint vine
#

Find the polar coardinate of (3,3)

merry knot
#

one of the many problems with geometry problems that don't define everything in words

faint pasture
blazing raft
#

@oblique pagoda

oblique pagoda
#

Hello
So uhhhh
My exercise is to derive the trigonometric theorems with the Euler relation
Everything on the top is…bullshit, don‘t bother with that because I think it was a mistake
I very feel like the result is just in front of my nose, but at the same time, I‘m not moving at all and wasting time
So it would be nice if you helped me out

blazing raft
#

Whoa that does look bullshit

#

@manic tusk help my gang member is struggling

oblique pagoda
#

I‘m not your GIRLFRIEND BROOO

blazing raft
#

LOL

manic tusk
#

Wtf

merry knot
somber coyoteBOT
#

daniel

oblique pagoda
#

That is what I did

merry knot
#

Sorry I didn't look at your work

trail tendon
#

e^iy = cos(y) + i sin(y) tho

#

i think is missing the i

merry knot
#

Yes there is a missing i

#

If you add the missing i and recalculate both sides, then equate real and imaginary parts, you get the result

oblique pagoda
#

Oh

#

I wish I had eyes

#

Thanks a lot! That must be revolutionary for my answer

trail tendon
oblique pagoda
#

BWHAHAAAHAHAHHAA

blazing raft
#

XDDDDDDDDDDDRIZZ

light dock
oblique pagoda
#

You‘d be surprised how unconcentrated I can be
But yeah, you‘re right, thanks for the reminder

dusty junco
manic tusk
somber coyoteBOT
#

Couldn't find an attached image in the last 10 messages.

manic tusk
#

,rotate

somber coyoteBOT
manic tusk
#

@lyric notch whatve you tried

junior wigeon
#

how is k expressed in the format of x/k + d when the k in the function is a fraction

manic tusk
junior wigeon
manic tusk
#

x goes to 5x yeah

#

so you can do mapping rule

junior wigeon
#

okay thanks for the help kannawave

#

is there a way to solve this algebraically or should I graph it?

manic tusk
# junior wigeon is there a way to solve this algebraically or should I graph it?

for a), the easiest thing you can do is find points a, and b where the function f is equal, so then the avg rate of change [f(b)-f(a)]/[b-a] = 0. like, you could find a point on the midline, and then add the period to it, and the function would be the same, so the avg rate of change is 0
then for b) you can go from the max to the min (or from the max to the middle), and for c) you can do the opposite

if thats confusing, this would be the visual of what im saying for each subquestion

vapid gust
#

hi

ripe widget
blazing raft
weak plaza
#

can someone explain the steps for me?

trail tendon
#

specifically, the two ways to compute it?

weak plaza
#

vw/|v||w|

#

problem is I cant figure out how to get |v| or |w|

#

it doesnt do a good job explaining

neat yarrow
weak plaza
#

can someone help me with this one too

#

im supposed to convert it to 11cos270 and 11sin270 right

near topaz
weak plaza
#

i figured it out I was applying tan accidentally

drifting zealot
#

Does anyone have any tips for Proofs?

sinful cobalt
#

feeling dumb posting this here but im super behind n I gotta lock in but would it make sense to say angle c is reflexive?

obsidian harness
#

what is true however is that angle ACB = angle DCE

#

cause vertically opposite angles have the same measure

weary plume
#

The graphs of trigonometric functions always appear to be constituting of consecutive rapid growth and decay. Can I model a given interval using a logarithmic or exponential function? Just out of curiosity.

obsidian harness
#

you should probably add together multiple exponential functions and logs though

#

here's a nice example for sin x

autumn surge
#

A clock has 6 hands instead of 3, each moving at a different speed. Here are the speed values for each hand:

1: Moves forward by $\frac{x}{12}$ degrees each minute

2: Moves forward by $x^2$ degrees each minute

3: Moves backward by $x$ degrees each minute

4: Moves forward by $\frac{x}{2}$ degrees each first minute and $2x$ degrees each second minute

5: Moves forward by $x$ degrees each minute

6: Moves backward by $\sqrt{x+y}$ degrees each five minutes

We know that two of these hands are the real minutes and hours hands, but that there is no seconds hand.

$y$ is a prime number that is a possible value for minutes in a clock, e.g.: 59 works, but not 61.

At the start, the clock shows midnight, which is the actual time. After a certain amount of time, 4 hands meet in one one spot, while the other 2 meet in another spot.

Question: What is the actual time?

somber coyoteBOT
#

⛊Alpha™

spark wasp
#

Where i can find all of the geometry formulas

wise pawn
#

doesn't exist

autumn surge
#

yeah

maiden brook
weary plume
#

Logistic appeared to be the best option

meager flax
#

Wonder how will it be solved

tame scarab
#

Hey help me with this question please

Among all the rectangles with a perimeter of 20cm, determine the one with the maximum area

#

My result is 32cm

#

cause 4+4+4+8 =20cm perimeter

#

4*8 = 32cm²

bright sedge
#

That is not a rectangle though

#

4x4x4x8 is a quadrilateral but not a rectangle

#

It would look something like this which makes it a trapezoid

#

You can let w and l be width and length. The area is wl and 2w + 2l must equal 20 ( the perimeter ) so w + l = 10, so w = 10 - l. If you substitute this into the area, you get l(10 - l) or 10l - l^2

#

That is a quadratic that represents all l values that work and the y-value is area. If you graph it, it looks like this and you can see area is maximized at the peak

#

The length there is 5 and so the width is also 5. The maximum area with that perimeter is a 5cm by 5cm square, with an area of 25cm²

trim ore
#

A circle line is drawn around the triangle. One angle of a triangle is 50 degrees. Calculate the narrow angle between the bisectors of the other two angles.

I have been stuck on this problem and I cant figure it out. Could someone please help me with it?

regal wedge
stray cedar
#

Someone teach me trigonometry

regal wedge
#

send a screen shot

regal wedge
bright sedge
#

Do you know what the law of sines is?

#

What is the problem then?

#

Yes I am aware what it is. What do you need help with, if you know what it is too? Do you want me to walk you through a question or?

#

You can solve for AC

#

Okay so there's your answer

#

Also it should actually be ~14

#

24 * sin(22 degrees)/sin(40 degrees)

#

How did you get 31.6

#

Did you type it in wrong

wise pawn
#

stop spamming this please

trim abyss
#

hi

upper karma
#

<@&268886789983436800>

drifting zealot
#

Are there any tips for proofs?

#

HELP ME

regal wedge
drifting zealot
#

Are there any general tips or advice for writing proofs, specifically in a form with two columns. Statements and Reasons.

regal wedge
#

angle chasing is fun

#

congruency is useful

grand tulip
#

js remeber every little step needs writing so even if basically anybody with any level of math advanced beyond prealgebra can understand it you still have to write it

#

and dont stress about axioms when substituion can be aplied

lyric halo
#

The circles having radii A and B intersect orthogonally. The length of their common chord is:

#

@faint pasture

faint pasture
#

2ff1 + 2gg1 = c+c1?

#

Actually wait

#

Im dumb we dont need that

faint pasture
#

C is the length of the common chord

lyric halo
wise pawn
#

,rotate

somber coyoteBOT
lyric halo
#

@faint pasture @wise pawn

faint pasture
#

So i dont rrally have a clue

#

Wait a minute

#

Its just h1+h2= 0

Because of the family of curves thing

#

Ie all the intersection points of s1 and s2 also satisfy

#

S1 + Lambda S2 = 0

#

Lambda is just an arbitary constant

#

Doing that in here and subbing lambda = 1 gives us a circle as the curve if we consider only the x^2 and y^2 coefficients

#

And it would be a circle if coefficient of xy =0

#

I really need to revise circles

#

@lyric halo

lyric halo
#

i see

wide lynx
#

This identity holds, right?
$\sec(x+\pi\cdot k)=(-1)^k\cdot \sec(x)$

somber coyoteBOT
#

horizon2.0

vestal shard
#

Can someone help me to prove the angle ACD is equal to the angle HKB?

dry junco
#

Can anybody help me with this question?

obsidian hornet
restive mauve
#

Is it only me or as a beginner, I find really easy to remember sin, cos, tan?

obsidian harness
#

great, move onto more challenging stuff if you're ready

#

especially if you've already done a million right triangle find the side / angle problems, and it's making sense

wise zodiac
#

what is the volume of the largest cylinder that can fit inside a closed rectangular box measuring 12 inches by 10 inches by 8 inches?

#

What’s the justification for why the cylinder can’t be along the space diagonal of the rectangular box? is it just because it intuitively feels like it leaves empty space?

#

Like relative to keeping it horizontally or vertically

faint pasture
#

Lets see

#

Mods would like to see this probably

#

<@&268886789983436800>

spark stag
#

bizarre

golden fiber
#

Hello can sb help me with this task pleas?

#

I would be very grateful for any tips because Im strugling with this task for very long time

golden fiber
#

Sorry its he right drawing to this task

upper echo
upper echo
azure helm
#

how can I come up with the identity by myself

#

sin(2x) = 2cos(x)sin(x)

cunning lion
#

from the angle sum identity

novel shadow
#

Im gonna go insane i believe its 4.5(root thing) 3/9 but idk

obsidian harness
somber coyoteBOT
#

southlander!

obsidian harness
novel shadow
#

Heck yeah im right then!!
Thx!!!

#

:DDDD

#

Found another one im struggling with (sorry)
The adjacent should be x(square root thing) 3
I dont know how to get x in this

#

The opposite should be just x

obsidian harness
#

oh yes you need to rationalise

somber coyoteBOT
#

southlander!

obsidian harness
#

I originally wrote 1/sqrt(3) but that's equal to sqrt(3)/3 by rationalisation

novel shadow
#

Yea

#

Im so confused on this Q^Q

obsidian harness
somber coyoteBOT
#

southlander!

ionic thorn
#

How to show Beta = 2 * alpha

#

so far, I know Beta = gamma + alpha

#

and Gamma = delta

merry knot
#

are the sun rays parallel to the x-axis?

ionic thorn
#

yes

merry knot
#

then delta = alpha by parallel lines

ionic thorn
#

is that a theorem?

merry knot
#

I guess

#

Idt it has a name

#

Corresponding angles are equal

ionic thorn
#

Ohhh I see

#

you do it from delta opposite and then transition to alpha

#

thank you!!

latent crow
#

paris pamfilos' lectures on euclidian geometry is ass

merry knot
#

Just read EGMO

latent crow
merry knot
#

Your loss

#

Still, read EGMO

latent crow
#

he fell off after the episodes started repeating the same procedure

#

what is egmo

merry knot
#

Euclidean geometry in mathematical olympiads

latent crow
#

although my statement was one of general acknowledgement

#

i will consider your suggestion

maiden brook
#

i think aops does it better but its a lower level

south elm
#

HELP

#

My teacher sucks at teaching and I’m failing the class with a FINAL of 68

#

I’ve never failed so bad before

glossy pecan
acoustic field
#

Guys help me figure this out: determine cos(2pi/3) using the ratio 30-60-90

acoustic field
#

okay thanks!

loud ridge
acoustic field
#

yesnt

obsidian harness
# glossy pecan

assume there exists a triangle XYZ such that XY = 4, XZ = 8, and YZ <= 4

#

show this breaks the triangle inequality

#

hence by contradiction, YZ > 4

#

oh well YZ = 4 is a degenerate triangle, so the statement you have to prove is not technically correct

upper karma
#

WAIT

#

NO

#

What have I done

thorn cradle
#

Does anyone know what this rule is called (if it has a name)

obsidian harness
#

$\frac{a}{b + c} = \frac{b}{a}$, (short leg) / (hypotenuse) constant

somber coyoteBOT
obsidian harness
#

$\frac{e}{b + c} = \frac{c}{e}$, (long leg) / (hypotenuse) constant

somber coyoteBOT
obsidian harness
#

$\frac{d}{c} = \frac{b}{d}$, (short leg) / (long leg) constant

somber coyoteBOT
chrome token
#

can someone give me a hint?
A circle is outscribed around the triangle ABC. Chords, from the middle of the arc AC to the middles of the arcs AB and BC, intersect sides [AB] and [BC] in the points D and E.
Prove that (DE) is parallel to (AC) and passes through the centre of the inscribed circle.

Ik the angle bisector thing(that it passes through middle of arc)

#

idk how to approach

glossy pecan
#

@obsidian harnesstysm

obsidian harness
serene bay
#

can someone here explain trigonometry real quick?

obsidian harness
# serene bay can someone here explain trigonometry real quick?

This video tutorial provides a basic intro into trigonometry. It explains how to evaluate trigonometric functions like sin, cos, and tan using soh cah toa and right triangle trigonometry. It explains how to use reference angles and coterminal angles to evaluate trig functions such as sec, csc, and cot.

Trigonometry - Free Formula Sheet: ...

▶ Play video
#

if you have any questions about the videos you can ask here

acoustic field
# upper karma I meant 60°

Too late now i failed the test ive worked so hard to prep for (it was mainly on cos and sin, this was in the study guide)

serene hedge
#

<@&268886789983436800>

light dock
#

please don't advertise this here.

#

the server isn't really for advertising your paid tutoring services.

twilit girder
#

hi guys so we did a test recently and I got a different answer then my friend, he got 9 while I got 3.9 for X. I have a feeling I did something wrong can anyone correct me?

exotic ore
#

x= 9

#

use the side lengths

#

simply the porpotions

#

so do 77/21 = 11x +11/30

#

and then solve for x

#

77/21 x 30 = 110

#

110 - 11 = 99

#

11x = 99

#

x = 99/11

#

x= 9

#

@twilit girder

twilit girder
#

aw man

#

well thanks anyways

exotic ore
#

np

twilit girder
exotic ore
#

u did 11x + 11 /21

twilit girder
#

yeah

exotic ore
#

i think you kinda got the picture right in your head but you executed it wrong

#

its because that wasnt the porportional adjacent side

#

with ur image it kinda looks similar so i can see why u got confused

twilit girder
#

in the question the triangle was the opposite way so I switched it, my friend thinks that could of caused the mistake

exotic ore
#

yh

#

u confused it around

#

becuase if they are porportional means it has the same ratio to each other

#

so u divide it by each other to find x since they are similar

#

if a and b are proportional a/b is the same value

#

if u understand

twilit girder
#

yeah I see where its going

#

thank you 🙏

exotic ore
#

np

indigo wadi
#

Can someone help me with this question? Im not sure if the solution takes the form of a ± or not

sin(arcTan(1/x))

twilit girder
tiny burrow
#

any tips

#

It's pretty complicated for me

twilit girder
tiny burrow