#geometry-and-trigonometry

1 messages · Page 351 of 1

honest pumice
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a can can be 0 to pi/4 on the positive x and y axis

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and many other values

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but the unit circle has a circumference of 2pi

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and can keep measuring a with more than 2pi

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or less than 0

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by just adding 2pi + the extra angle you want

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you should really study the unit circle

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it's essential to know it

valid magnet
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yes

honest pumice
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can't really explain it with words here in a chat

valid magnet
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i'm trying to figure out how to calculate the hypotenuse of a right triangle w/o doing sqrt(x^2 + y^2)

valid magnet
pearl finch
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can someone show me how this is wrong? tag me if u have a reasonable explanation plz

pure cape
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remember, they are asking for the slope of segment WZ not segment YZ

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segment WZ is perpendicular to YZ at Z

pearl finch
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@pure capedude how do u know that

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without drawing anything up?

pure cape
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that's because WXYZ is a rectangle

pearl finch
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so a rectangle has specific rules is what you're saying?

pure cape
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what do you mean by specific rules?

pearl finch
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like, specific rules when it comes to questions like this

pure cape
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if a rectangle is named WXYZ, the vertex has to follow that order

pearl finch
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so something like this

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im so confused lol

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something's just not clicking

pure cape
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for example this rectangle is not WXYZ

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this rectangle is WYXZ

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it has to follow an order, thats just how they are named

pearl finch
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oh

pure cape
pure cape
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and the question asked for the slope of the segment WZ, and not YZ

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but you answered the slope for segment YZ

pearl finch
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ohh i get what ur saying

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it always has to have a certain order

pure cape
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yes

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you can read it from any vertex you like

pearl finch
pure cape
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but it has to either go in anti-clockwise or clockwise order

pearl finch
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yeah lol

pure cape
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or ZWXY

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it doesnt matter, you just need to get the order right

pearl finch
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yeah but it's always following that order

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yep

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and since it's perpendicular to the slope we already know

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it'd have to be 3/2

pure cape
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yes

pearl finch
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tysm'

trim laurel
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i put the points but how do i get the angle?

dark sparrow
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you don't need the angle itself tho

trim laurel
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yea ik but i need to get it

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so then i can get the ratios

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i dont understand how to get it tf

dark sparrow
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no you don't need theta itself

trim laurel
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what do i need

dark sparrow
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you need the point where the ray OP intersects the unit circle

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its coords will be (cos(θ), sin(θ))

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you can also find this by dividing each coordinate of P by the length of OP

trim laurel
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what?

dark sparrow
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O stands for origin of course

trim laurel
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we never did that before

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do i even need theta

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if i have a, b, and c

dark sparrow
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this is what i was talking about

trim laurel
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we never did that tho

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this is hs

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it says to get the ratios

dark sparrow
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but you can also get yourself a right triangle instead. just be mindful of the signs

trim laurel
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it is a right triangle already though no?

dark sparrow
trim laurel
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yea

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thats what i got

dark sparrow
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yeah ok so you have two of its sides given to you

trim laurel
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9 is adjacent

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then find hyp

dark sparrow
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and the third is the hypotenuse, which can be worked out using the pythagorean theorem

trim laurel
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i got square root of 63

dark sparrow
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sqrt(63)? that looks sus

trim laurel
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which is 7.9 but i wrote it as 3 times the square root of 7

dark sparrow
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show work?

trim laurel
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okay

dark sparrow
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i think you fucked up your arithmetic somewhere

trim laurel
finite edge
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-12 times -12 is not -144

dark sparrow
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^

trim laurel
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ohhh i fucked that up

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okay thanks

dark sparrow
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i mean you should've gotten a red flag when you tried to shove a negative number (-63) under the root

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instead of just sweeping that minus under the rug

trim laurel
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helped more in 2 minutes than anyone else

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so hyp is 15

dark sparrow
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yes the hypotenuse is 15

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now you have enough info to get all three trig ratios of theta

trim laurel
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appreciate it

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got it

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i have 2 more questions that im reallllly confused with

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if ur willing to help

dark sparrow
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is #4 the same angle θ that we worked with in the previous problem

trim laurel
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i dont think soi

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so

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i thought it was

dark sparrow
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no i mean like

trim laurel
dark sparrow
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is there a different point or something

trim laurel
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maybe this will help

dark sparrow
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for problem 4

trim laurel
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yea i think its completely different

dark sparrow
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okay then youll have to give the coordinates of the new point

trim laurel
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so that means it is connected to 4

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because how else would we get the coordinates

dark sparrow
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...

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???

trim laurel
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im saying like

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it says of the right triangle

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oh im an idiot

dark sparrow
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in problem 3 we worked with the angle whose terminal ray contains the point P (9, -12)
in problem 4 are we still looking at the same angle or not

trim laurel
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no

trim laurel
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do we use the 45 degree triangle for this?

dark sparrow
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what????

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hold on

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what angle is even being talked about in #4?

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is #4 a continuation of #3 or not???

trim laurel
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no

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i dont think it is, it wouldve said

dark sparrow
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okay then WHAT ARE THE DATA FOR PROBLEM 4

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theres no data

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no data no answer

trim laurel
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lmaooo thats what im saying but i think he told us that whenever we see "right triangle"

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we use special triangles

dark sparrow
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who's "he"

trim laurel
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my teacher

dark sparrow
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and who is he to claim that right triangles with angles other than 30, 45 or 60 degrees just don't exist

trim laurel
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hes not saying that

dark sparrow
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either your teacher has done a poor job of writing down the problem(s) in a clear and solvable manner

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or you're misleading me into thinking there is no data given for problem 4

trim laurel
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hes saying that whenever we do get one of those angles, we use the hyp adj and opp angles he gave us

dark sparrow
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okay but we don't have an angle at all

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let alone any of those three

trim laurel
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misleading? but how would I know because it doesnt say anything about 4

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i mean 3

dark sparrow
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fucking hell

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this is a communication breakdown this is a communication breakdown this is a communication breakdown

trim laurel
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ill look in my notes for something related to this

dark sparrow
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your notes are useless

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this isnt a notes issue

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this isnt a knowledge issue

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this is a reading comprehension issue

trim laurel
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yea i know

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because the question doesnt say if its connected to the angle we got in 3 or not

finite edge
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hey ann the diagram says use it for the next 2 questions

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so 4 has the same point P

trim laurel
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ohhh

dark sparrow
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SEE THATS WHAT IM TALKING ABOUT

trim laurel
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it does

finite edge
dark sparrow
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but moe was insisting

trim laurel
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i didnt see that lmao

dark sparrow
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that that wasnt the case

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for some reason

trim laurel
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LMAOOOO

dark sparrow
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ARGH

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okay

trim laurel
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i wasnt insisting i said i think so looool

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my bad fr

dark sparrow
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so we still have our triangle with sides 9, 12 and 15

trim laurel
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-12*

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yea

dark sparrow
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we're looking at the reference angle

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which is in the first quad by defn

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so that side is just 12

trim laurel
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why first?

dark sparrow
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reference angle

trim laurel
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opp is negative

dark sparrow
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reference angle

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the reference angle of θ is the angle in the first quad whose sin and cos are the same as the original up to sign

trim laurel
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i still have no idea what you mean

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wouldnt it be in quad 4

dark sparrow
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theta itself is in quad 4

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but im talking about

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the

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reference angle

trim laurel
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yes ik

dark sparrow
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and if you didnt know what that means you could have and should have asked me outright

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and made both of our lives easier

trim laurel
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ik what it is

dark sparrow
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great

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so you know that the reference angle always lies in the first quad

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by its very definition

trim laurel
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WHAT

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bro WHAT

dark sparrow
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don't call me bro...

trim laurel
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so ur saying that there cant be a reference angle in quad 2 3 or 4?

dark sparrow
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reference angles are acute

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by definition

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no matter which quad the original angle is in, the reference angle will be acute

trim laurel
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aight

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i just thought that since we're in quad 4 i thought the reference angle would be also

dark sparrow
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no the reference angle is acute

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no matter what quadrant the original is in

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the reference angle is acute

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as ive said like a dozen times already

trim laurel
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so to get an angle i can use cos-1(3/5)?

dark sparrow
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cos^-1(3/5) yes

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if you wanted you could also do sin^-1(4/5) or tan^-1(4/3)

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these all give the same result

trim laurel
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and that gives me the reference angle

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so ref angle is 53 degrees

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and the other angle is 127?

dark sparrow
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,calc acos(3/5) * 180/pi

somber coyoteBOT
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Result:

53.130102354156
dark sparrow
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okay yes 53°

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but why would the other angle be that large all of a sudden

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its also supposed to be acute

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which 127° decidedly isnt

trim laurel
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oh

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so how do i get the other angle

dark sparrow
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how did you get this 127° angle?

trim laurel
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oh is it 180-53/2

dark sparrow
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no? why half

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did you subtract 53 from 180?

trim laurel
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yea

dark sparrow
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and who will account for the right angle that's already present?

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and which contributes 90 degrees to the angle sum?

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which you just went and lumped in with the other acute angle...

trim laurel
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is the other angle 37 degrees

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180-90-53

dark sparrow
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yes it is

trim laurel
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thank u

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helped a lot i appreciate it

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what kind of triangle do i use for this

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if it says how long, would it mean the adjacent side?

dark sparrow
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make a diagram

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wait hold on

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"at an angle of 15°"?

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that's ambiguous

silent plank
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the wording of the problem is so bad and vague

dark sparrow
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theres like a dozen different places the 15° angle could go honestly

trim laurel
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the angle is for the side 30m

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thats what he means

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yea ik he words all his shitty questions like this

dark sparrow
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"the angle is for the side 30m" is not any better

trim laurel
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yes it is

dark sparrow
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can you draw a diagram that shows your interpretation

trim laurel
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we use the sine law for this

dark sparrow
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because i'll be honest

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i have no idea what's going on

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and i need you to explain yourself to me

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with a diagram

trim laurel
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im trying to figure out what triangle to use for this

dark sparrow
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why is "make a diagram" not the first priority in your process for solving geometry problems???

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can you draw a diagram

trim laurel
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because ive never made one for trig lol

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yes i will

dark sparrow
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okay make your diagram and ping me when it's done and show it to me

trim laurel
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nah i cant even understand it

silent plank
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is probably the most reasonable interpretation

trim laurel
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no but the 15 should be on the other side

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because it says 30m at an angle of 15 degrees

silent plank
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that statement implies that the 30m side forms an angle of 15degrees with another side

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here, its the length of the pond AB

trim laurel
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yea im confused bro

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i wouldve put 15 at the other side because its referring to 30m

dark sparrow
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the question itself is confusing

silent plank
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ignoring the wording of the question,
would you be able to calculate the length of the red line AB?

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(bring up the wording issue with your teacher)

trim laurel
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yea probably

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id use cosine law

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no i did it wrong

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because i got 22 m

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that doesnt make any fucking sense

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@dark sparrow did u figure it out?

dark sparrow
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going by ramonov's picture... let me calculate it rq

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yeah 22 is way off. how did you get it?

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the answer i got is ||78 m, to the nearest meter||

trim laurel
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i used cosinse law

dark sparrow
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show your work.

trim laurel
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so i did (50^2+30^2)-(2(30)(50)cos(15))

dark sparrow
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this does not correspond to ramonov's picture

silent plank
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ur not applying the cosine law properly

dark sparrow
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note the placement of the 15° angle. it is not between the two known sides.

trim laurel
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yea its for the unknown side

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oh

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i mean 30m

dark sparrow
trim laurel
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so what do i do

dark sparrow
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apply the cosine law properly.
perhaps you could denote the unknown side with a letter like x, and write out the law of cosines in terms of that

trim laurel
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okay

dark sparrow
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in your case you will get a quadratic equation in x

trim laurel
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im not doing it right

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can u please show ur equation

dark sparrow
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$50^2 = 30^2 + x^2 - 2 \cdot 30 \cdot x \cdot \cos(15)$

somber coyoteBOT
trim laurel
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i dont understand how angle 15 is corresponding to 50m

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the angle is for 30m is it not?

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because the angle isnt right next to the side, its the opposite of the side

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@dark sparrow

dark sparrow
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??

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the 15° angle is between the 30 and x, and opposite to the 50

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c^2 = a^2 + b^2 - 2ab cos(C)

trim laurel
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oh

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I thought that 30 m was at an angle of 15

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and ur saying that its between 30 and x which i understand, but if it was 15 degrees would be right next to the 50m

dark sparrow
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but if it was 15 degrees would be right next to the 50m
then you would have a different diagram

trim laurel
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Yea that’s what I mean

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That’s why I think the diagram he made was wrong

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But I was wrong too though

hot flume
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I may have an idea

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I used CH as the height of the triangle and now I have 2 rectangle triangles

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Therefore I can use trivial trigonometry

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But maybe I'm wrong, what do you think?

trim laurel
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Well what’s ur answer

hot flume
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Around 78

trim laurel
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Also

hot flume
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Seems legit

trim laurel
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Why did u put 15 on the 30 m side?

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Shouldn’t it be on the 50m

hot flume
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I saw the draw above

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So I put it here

trim laurel
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If the question said 30m at an angle of 15 degrees

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Would it be on the 50 m side?

hot flume
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U mean, the angle ACB would be 15 °?

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Or cba?

trim laurel
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No

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Put 15 degrees at the other corner

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That’s what I mean

hot flume
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O okay

trim laurel
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Yea would that be right

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Because the angles have to be on the opposite side

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Idk though because ann said ur way is right

hot flume
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Yeah but maybe my way doesn't answer the right question

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Maybe ur right and this is not the right angle...

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I don't really know, did a teacher gave it to you?

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If so, u could ask him

upper karma
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what does this sign mean

dark sparrow
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"straight line" maybe?

upper karma
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If u have 2 points, connect them with line segment and draw two circles with center one of them radius line segment length it will intersect in 2 points. if u connect those they will intersect line segment. How to prove that that intersection point is the middle of the 2 original points?

dark sparrow
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so you have two points A and B, and you have two circles with radius AB, one centered at A and the other at B

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and they intersect at two other points C and D

upper karma
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yea

dark sparrow
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and youre asking how to prove that CD bisects AB

upper karma
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no

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uh maybe

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idk what bisects means

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intersects at mid

dark sparrow
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splits into two equal parts

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yes

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okay

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there are different ways to go about this

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the simplest would be to just say the whole picture is symmetric about CD or something

upper karma
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yea it seems to be

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how to formalize that tho

dark sparrow
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mmm

tiny snow
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@upper karma If you are allowed to use knowledge about a rhombus, the construction in blue is sufficient. If not, you can create two larger triangles (orange) which you can prove are equilateral, from which the symmetry then follows.

tired knoll
dark sparrow
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not enough info lmao

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oh wait

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AC = 2

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misread as OC

tired knoll
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whats ab thou

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ik the traingle is a right triangle

dark sparrow
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AB is what you need to find lol

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what's "it"

tired knoll
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yepp ToT

dark sparrow
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OAB is a right triangle thats correct

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OAC however is equilateral

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all of its sides have length 2

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now what do you know about equilateral triangles

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(also, never use the word it in math unless you are absolutely 110% certain that you understand exactly what the word refers to)

tired knoll
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oo

dark sparrow
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??

tired knoll
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nvm

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but how do you find ab from that?

dark sparrow
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now what do you know about equilateral triangles?

tired knoll
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they have the same angles and sides

dark sparrow
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how big is each angle in an equilateral triangle?

tired knoll
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60

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degrees

dark sparrow
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60 degrees, that's right.

tired knoll
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oooooo

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nvm

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thank you god

dark sparrow
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so in particular, angle AOC (which is also known as AOB) is 60 degrees

tired knoll
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tyty

upper karma
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what's the difference between barycenter and circumcenter?

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i can see that it does 3 90° angles

dark sparrow
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eh?

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afaict barycenter is another name for centroid in the context of triangles

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centroid is the intersection of the medians

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and the circumcenter is the intersection of the perp bisectors

upper karma
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oh

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why is a circumcenter commonly shown with a circumscribed circle on the triangle

dark sparrow
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because that's what the circumcenter is

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it's the center of the circumscribed circle lol

upper karma
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oh

median needle
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help me in this one i am feeling stuck tried various ways to approach the question but still stuck

lost hound
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im taking a trig final on tuesday if anyone has any practice problems that i could use it would be much appreciated

zenith garnet
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this is just a trapezoid right?

junior light
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Yes. How would you prove it, though?

warm locust
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is there a way to construct the height of a triangle with ruler and compass? (there must be i feel like) i want to prove that, given a triangle, you can construct a square with the same area. my approach was to just construct sqrt(1/2gh)., because i know that you can construct the square root of a constructible number. 1/2 is constructible and g is given, so i just need to show that h can be obtained

tame panther
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Cant you just measure from one point of the triangle, perpendicular to the opposing side to find the height?

warm locust
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but can i measure perpendicular ?

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well wait

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no i think you are right. lmao i

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m dumb

tame panther
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Keep one side of the ruler on the top point, and move the other side of the ruler around until you have a 90 degree angle with the bottom of the triangle

warm locust
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yea, thanks 🙂

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or wait no if i keep the needle of the ruler on the topside of triangle then i can measure the distance until i reach the base, but i can't say for sure that it is a right angle. I can just approximate

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hmm well i think this was maybe lost in translataion, compass in my language can just be used to connect two points with a straight line

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so i can't measure angles with it

tame panther
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I got compass mixed up actually

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I was thinking you could measure angles with it

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I'm trying to think how to measure a right angle with your tools

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I have an idea but it is a little cumbersome

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Put one side of the compass on the top of the triangle, put the other side where you think the perpendicular point is

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Draw a small portion with the compass and it should be tangential to the base

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That tangent point is perpendicular

warm locust
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yup i found another way too

tame panther
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Great. That also works

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That way is more accurate too

warm locust
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i really like these construction problems 😄

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pretty elementary but still satisfying if you get it

tame panther
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Yes I get it. Math can be very satisfying

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I recall reading about an ancient greek mathematician who spent lots of time trying to solve geometry problems with only a ruler and compass. Possibly pythagoras?

warm locust
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i think many greek mathematicians thougth about these constructions. I mean euclid formulated his entire elements in terms of construction with ruler and compass afaik

tame panther
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It must be Euclid that I am thinking of

warm locust
#

could be ^^

tawny dragon
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Are you guys familiar on how to find circle diameters. If so can you help me out with this question?

mellow gate
#

Tan can or cannot involve hypotenuse?

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If opposite is hypotenuse?

tiny snow
tiny snow
vapid stag
#

Hello, my professor is showing us the ways to find the asymptotes for sin,cos function through using -2pi < x < 2pi. Is this part of the squeeze theorem? I watched a lot of tutorials on trig and they all showed a different way to solve the problem. Which one would you guys recommend?

humble pulsar
vapid stag
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i meant to find the points to graph it over one interval period.

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i'm still confused on whether to use it or not.

humble pulsar
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Ok so if you're picking points to plot the graph.. where does squeeze law come into play?

vapid stag
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let me see if i can pull up an example he did

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this is what he used. which I'm kind of confused on what it is. and wonder why it's so different than how all the youtube tutorial is lecturing a different way to find the solution.

humble pulsar
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that's not squeeze law

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that's just the domain of 1 period

vapid stag
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understood

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i'm kind of lost in what it's supposed to help me find. do you by chance know the purpose of it?

humble pulsar
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to find the domain of a period

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sine is 2pi-periodic so $\sin(\theta)=0 , D={\theta \in\mathbb{R}|0\leq \theta\leq 2\pi}$

somber coyoteBOT
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moshill1

dapper bronze
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20 and 21 can anyone help?

trim breach
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What immediately comes to mind is drawing segment HA to form right triangles within the kite and solving that way.

waxen roost
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need help with this

trim breach
waxen roost
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nvm I solved it

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I saw a tutorial on youtibe

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can someone tell me how to solve this

ember canopy
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where h=6 and r=8

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thats the bigger cone

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then find the volume of the smaller cone

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and subtract it from the big one

waxen roost
final pine
#

Whole - the other piece

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The whole cone is 6 and 8 and the small cone is 3 and 4

waxen roost
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I hope I did it correct

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@final pine

golden garnet
#

Anyone wanna help me solve this? This is an ixl study guide for my upcoming quiz and was stumped on this question. The assignment does not go towards my grade but I would like to know how to do a question like this.

waxen roost
blissful willow
dark sparrow
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@blissful willow do not give out answers here

cosmic sundial
long garnet
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i'm confused about this review question for our test, can anybody help?

faint bramble
slim saddle
#

the volume of the barrel is 20pi

slim saddle
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<@&286206848099549185>

compact jasper
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Sometimes i see this formula. but what is C? 🙂

silent plank
#

circumference of the circle

trim breach
foggy talon
#

Hello can someone tell me how to solve this

dreamy ridge
#

The two expressions are equal

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Bc thats the property of rectangles

valid magnet
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((59 - 25) / (6-4)) = 17

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we notice that the differnce between 59 and 25 are 2c

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2c = 34

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59 - 25 = 34

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(59 - 25) / 2 = c

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@foggy talon

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when you look at the 25 and to get to the 59, you add 2c to 4c

foggy talon
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so 6c?

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4c+2c=

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6c

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Thank you @valid magnet

valid magnet
#

4 * c + 2 * c

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not sure if it's equal to 6 * c

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4 * 5 + 2 * 5 = 30

#

6 * 5 = 30

valid magnet
#

(4 * c) * (2 * c) = ?

quartz cedar
#

Would anyone recommend any books that could help you succeed in a trigonometry class?

valid magnet
#

i might be able to find you some free books related to trigonometry

quartz cedar
tall lava
#

Anyone down to teach me some trigonometry during my 4 hour car ride? 😂

trim breach
tall lava
#

Driving atm. I’m in 8kb channel, though. I just barely started learning and I don’t want to waste four hours doing nothing but drive. 😂 If you or anyone who wants to talk with a mic can just start from the beginning , that’d be helpful.

foggy talon
valid magnet
#

not 8(c^2) ?

foggy talon
#

Then I was mistaken

simple bear
#

How to verify this identity using de Moivre's Theorem?

zinc cradle
#

Hello all. Anyone good with some shapes

coarse shoal
#

could someone help please?

tender lion
#

i need to place these in a trigonometry circle

trim breach
# coarse shoal could someone help please?

I would recommend using trigonometric ratios to find x. The first triangle you have to actually do the algebra, but the second triangle can be solved easily if you recognize a pattern.

upper karma
#

For finding a length of an arc in geometry can it end as a decimal pi or just a decimal. Or does it have to be a whole number pi?

rancid sigil
#

@abstract barn put it here

abstract barn
#

k

rancid sigil
#

<@&286206848099549185>

#

Please help him

steady shoal
abstract barn
#

They dont understand geometry

#

SO they recommended I join this server

steady shoal
#

How old are you ?

abstract barn
#

16

rancid sigil
steady shoal
#

Do you know what the interior angles of a rectangle are ?

abstract barn
#

Yes

#

Ive repeateadly tried to solve, and I keep getting 14

#

and it just doesnt add abck up

#

*back

steady shoal
#

Can you share what you did

#

It’ll be easier if you use pen paper rather type

abstract barn
#

SO basically I used the given numbers and variables (3x-30) (2x+10) and multiplied by 4
Then I did 360-120(sum of the -20)
240+40(sum of the +10)
280/20=14

#

then I plugged 14 in and it just wouldnt add back up to 90

steady shoal
#

Why did you multiply (3x-20) and (2x+10)

abstract barn
#

didnt multiply them by each other but by 4

steady shoal
#

Why

abstract barn
#

I guess I tried to take a shortcut and screwed up tbh

steady shoal
#

No you possibly took the longest path

abstract barn
#

oh

steady shoal
#

What’s the interior angle of a rectangle

abstract barn
#

360

#

in total

steady shoal
#

And at the corners ?

abstract barn
#

90\

steady shoal
#

Use that instead

abstract barn
#

what do you mean by that

steady shoal
#

You’ve been given an angle which must equal 90

abstract barn
#

Im not sure exactly how to set it up

steady shoal
#

Angle C is 90

#

You’ve been given angle c in terms of x

#

(3x-30)+(2x+10)=90

abstract barn
#

ok so its 22

#

Thank you so much

grim beacon
#

nice

waxen glen
upper karma
# waxen glen

This is simply melanous theorem , do u know it, or do i show u a proof?

#

There r plently of ways of doing this tho

waxen glen
#

let me research a bit please

#

$$\frac{AD}{BD}\frac{DF}{FE}\frac{BF}{FC}=1$$

somber coyoteBOT
waxen glen
#

@upper karma like this?

upper karma
#

Gimme a second pls

#

Lemme work this correctly

upper karma
# waxen glen

Ok a good way to solve this is areas, join be and af

#

Then let area of the big triangle abe be A

#

then area of adf = 5/9 area of ade = 5/9 ( 2/5A)

#

= 2/9 A

#

similarly area of bdf is A/3, and of bfe = 4A/15

#

Is this good?

rich wolf
#

,w 3/323 - 1/121

upper karma
#

how do I do this

grim schooner
#

use the two-tangent theorem

grim schooner
# upper karma

two segments tangent to a circle and that meet at an endpoint are both equal

#

so 28=3x+4

#

24=3x

#

x=8

tiny snow
waxen glen
#

i didint understand it

#

is there any video explains this concept

#

@tiny snow

tiny snow
#

Not that I am aware of... It's only arithmetics and similar triangles, with one additional parallel line drawn.

topaz nimbus
#

like BPT

#

basic proportionality theorem

upper karma
#

Guys.

#

It's simple:

#

I've found these three value scopes.

#

Should be there more?

#

Should be there the fourth one?

sturdy iris
#

I think you're fine

zinc cradle
#

If row 1 is length of outside line, then row 2 is the next inner line, what is the ratio of row1/row2 for an octagon

#

The numbers on the sketch are from ruler observation, not maths

upper karma
#

First to find the length of an n sided polygon in circle

#

Can you do that?

zinc cradle
#

Correct, if diameter is known, how to calculate the length of each side of polygon

#

I don't know that equation

upper karma
#

Ok , look at the triangle formed by the centre of circle and any two adjacent points

#

And split it into 2 right triangle

zinc cradle
#

It is 45degree of arc and the total diameter we will say is 100

upper karma
#

45 degree for any n sided polygon?

zinc cradle
#

In the picture, the first inscribed octagon each member will touch every 45 deg on the circle

#

This will be at full diameter of 100

upper karma
#

Yes, for octagon n=8 and arc=45degree
For any n, the arc angle will be total angle÷number of angles=360/n

#

K?

zinc cradle
#

Yes that is easy, but what is equation for side length

upper karma
#

Ye

#

Look at the half of that

#

Makes a right triangle

zinc cradle
#

Ahhh.. I think I got it, I look at it as a circle, not a square.

#

If I imagine the octagon in a square it's much easier

upper karma
#

Okay, that does work for this case, tho equation for length for any n side would be a=dsin(180/n)

#

d is diameter

#

Ok?

trim laurel
#

how do i get standard angle from referenec angle

#

my ref angle is 238, what is it in standard position? please help

sick torrent
main lintel
main lintel
sick torrent
#

yes

main lintel
#

So what is the problem?

sick torrent
#

I dont know the problem

main lintel
#

By problem I mean, why cant you solve it?

#

What causes you the trouble

sick torrent
#

yes how to solve it

main lintel
#

You know what is surface area? So where did you get stuck?

sick torrent
#

do i just multiply

#

all

main lintel
#

No, you add (sum) all surfaces.

main lintel
sick torrent
main lintel
#

You just need to sum each and every side on the image.

#

You said this is clear to you

main lintel
sick torrent
#

so 16 + 12 + 9 + 20 +

sick torrent
main lintel
#

There are 5 sides

#

bottom, top, and 3 "lateral"

#

Wait, you are confused a lot.

#

One thing is "side" the other is "edge"

#

Edges are the lines. Sides are surfaces.

#

This is one side:

#

This is not a side but an edge:

sick torrent
#

oh

main lintel
#

There are 5 sides. And there are 9 edges.

#

For Surface Area you need to sum the areas of all 5 sides (surfaces)

sick torrent
main lintel
#

How you got that number?

#

Bottom is: 16*12/2 = 96, top is the same.

sick torrent
#

than midle is 16 times 9

main lintel
#

"lateral" ones are: 16*9, yes.

#

Then 12*9 and 20*9

sick torrent
#

ok

main lintel
#

Yea, 624.

trim laurel
#

someone help pls

#

is this 344?

main lintel
#

How you got that?

#

Yea, I also got 344

trim laurel
#

i used tan-1(2/7) and got 16

#

rounded to 16

#

then it said larger than 180 but smaller than 360 so I used quad 4

#

360-16= 344

clever ginkgo
#

yo

#

<@&286206848099549185>

#

I know the ansawer is 6pi

#

but idk how

#

they got it

#

I dont understand how to do this

latent ore
#

Can you see that the shaded area is 3/8 of the circles area?

clever ginkgo
#

yea

latent ore
#

Right well

#

if the diameter is 8? What's the area of the whole circle?

#

$A=r^2\pi$

somber coyoteBOT
#

.itsjustnai

clever ginkgo
#

so is it

#

16pi?

latent ore
#

yep

#

so 3/8 of 16pi is... ?

clever ginkgo
#

hmm

#

6

#

:0

latent ore
#

6pi

clever ginkgo
#

Thank youSO MUCH!

latent ore
#

np

clever ginkgo
#

@latent ore wait but how did you get 3/8

#

like did you just wing it

#

I just guessed

latent ore
#

I winged it.

#

@clever ginkgo

clever ginkgo
#

OOOOOOOOOOOO

latent ore
#

I mean

#

You can also look at it this way

#

it's obvious the top part is 1/2 of the circle area

#

and the 45 degrees is 45/360 the circle area, which is 1/8

#

so 1/2+1/8=4/8+1/8=5/8

#

so the white area is 5/8

#

and the shaded one is 1-5/8 which is 3/8

#

if you're wondering why it's obvious the top part 1/2 of the circle area it's because RP is the diameter

#

@clever ginkgo

clever ginkgo
#

my hero

heavy tinsel
#

can someone help me with geometry

humble pulsar
heavy tinsel
#

Im not sure what the formulas are

trim breach
heavy tinsel
#

Im confused on what the formulas are for each one

trim breach
#

It is not necessarily a formula…it is using ratios between the two prisms.

#

The scale factor is simply the ratio of

humble pulsar
#

\frac{}{}

trim breach
#

^

#

,,\frac{x}{y}

somber coyoteBOT
trim breach
#

The ratio between the two prisms surface area is

#

,,\frac{x^2}{y^2}

somber coyoteBOT
trim breach
#

You can set up a proportion since you know at least three of these values since they are given in the problem.

pure cape
#

is there a method to solving open form trigonometric equation? For example like x=sin(x)

#

i have been thinking and it seems like it could only be solved graphically or numerically

dark sparrow
#

open form?

pure cape
#

im not sure how to say it

#

but its something like x=sin(x)

dark sparrow
#

transcendental equations

#

these are hard to solve exactly in most cases

pure cape
#

because im wanting to solve an equation that is almost like that over the variable, but since i cant do it algebraically, ig im stuck

#

more specfically Asin(bx+c)=x

dark sparrow
#

hm

#

is there any reason why you need the exact values of the solutions

pure cape
#

so basically thats part of a bigger problem. I need to find functions whose inverses are tangent to the original functions at point (a,b) on the line y=x

#

basically like e^(x-1) and ln(x) +1 which is the only exponential function i found

#

so i found the best way to do this is that since the inverse is symmetric to the original function thru y=x, we just need to find a function that is tangent to y=x

#

so i split it into the basic types of functions, (linear functions are off the table), power functions, which does not exist any that fits into the description, exponential functions (which i did and found only one function which is f(x) = e^(x-1) )

#

now im working on trigonometric functions which is really scary, i tried playing around, and found that sinx and arcsinx actually works

#

but the thing is, those are not the only one i think.

#

so which is why i need to work on it, i start off with the standard form f(x)=Asin(Bx+C), find the tangent point from the equation f(x)=x, and then substitute that x into f'(x)=1 to figure out the coefficients. im stuck at the second step

#

hmm i guess i think we can assume from the fact that sinx is tangent to x at (0,0). And it seems like only sin(x-a-2kpi)+a where a is in R, k is in N fits into the description

#

hmm

hallow wedge
#

please help

tiny snow
#

@hallow wedge There is something wrong with the terminology in the question. Altitudes intersect in the orthocenter. The medians of the sides intersect in the centroid.

upper karma
#

Pretty sure this falls under geometry

#

How do I solve for side length with only the area of the figure

trim breach
#

Is it a regular polygon?

upper karma
#

Yes

trim breach
#

You can think of the polygon in right triangles by drawing apothems and radii.

upper karma
#

That’s the thing it only gives me the area of the complete hexagon, not the apothem, side lengths, radius, or perimeter

#

I know the central angle is 60, and divided into a right triangle to come to 30 degrees but I have no further information to set up 306090

#

Each triangle has an area of 81 square root 3

trim breach
#

You have to do a bit of algebra. Might want to take a look at this video since they explain it better than I feel I could.

upper karma
#

Okay, thanks!

pearl finch
#

does anyone know how to solve this problem

dark sparrow
#

pretty sure a lot of people do

#

what's giving you trouble here? @pearl finch

pearl finch
#

bro idk

#

i just have no idea how

#

to solve this problem

#

like ive never seen problems like these before

dark sparrow
#

don't call me bro please

#

okay, let's see here.

pearl finch
#

ok just please help with this problem

#

some of these questions take my teacher so long to solve

#

these are the most difficult problems ive seen all year

dark sparrow
#

got a phone call sorry

untold cosmos
#

can someone help me on my geomtry test?

dark sparrow
#

@pearl finch do you know how to find volumes of cylinders and cones?

pearl finch
#

yes

dark sparrow
#

okay

#

so let's say you already knew the volumes of both of your shapes. would you be able to find how many times the cone's volume fits in the cylinder's volume?

pearl finch
#

i dont think so

dark sparrow
#

okay let's try a simpler problem. set that one side for a while

#

let's say you have a cup that holds 0.4L of water and a big jug whose volume is 6L

#

would you be able to find how many cups it'd take to fill the jug?

pearl finch
#

6/0.4?

dark sparrow
#

so you do know

pearl finch
#

oh wow

dark sparrow
#

same concept here

pearl finch
#

question was much less difficult than i imagined

#

hold on a minute

dark sparrow
#

except your cup is conical and your jug is cylindrical :p

#

but that only affects the calculations of their volumes

pearl finch
#

@dark sparrow thanks

#

is it normal to forget most of the math you've done in the school year if you havent practiced them in a while

dark sparrow
#

not really something specific to math

#

lack of practice in anything will make you forget it eventually

pearl finch
#

i feel so dumb because i cant remember enough to solve most of the problems :/

dark sparrow
#

sometimes you gotta step back and think

#

like. here the key was to understand that the volumes of your cone and cylinder were the necessary stepping stone between the givens and the answer

pearl finch
#

i removed all the old papers for the class because there was just nowhere to put them

#

and they were very messy

dark sparrow
#

that's unfortunate

pearl finch
#

some of the problems took my teacher 15 minutes to do lol

#

so im just wondering how i can complete it

#

is this AAS

dark sparrow
#

the distinction between AAS and ASA is nearly pointless as far as triangle congruence tests go but yeah the intended answer is AAS it looks like

pearl finch
#

how about this one

#

how is 67 wrong

dark sparrow
#

one moment

#

how'd you get 67?

#

(180-46)/2?

#

if so, that gives you angle ADB (or ABD, they are the same)
so it's simply not what was asked for

pearl finch
#

i assumed BAD was equal to ADC

dark sparrow
#

yeah well

#

that assumption is garbo

gusty estuary
pearl finch
#

no

gusty estuary
#

okay, this is how i worked it out:

pearl finch
#

ok i see a way how to get the answer

gusty estuary
#

First you take 46 and subtract 180 by it, because its a straight light (AD).

Once you get that answer, divide it by 2 to get the measure of angle B and D.

Once you have the measure of angle D, subtract that number from 180, which is going to equal the other side of D (ADC).

Then you subtract the new number from 180, and divide the new number by two to get your final answer

pearl finch
#

i got 33.5

gusty estuary
#

Yep

pearl finch
#

thanks

gusty estuary
#

Could anyone help me out with this?

#

i read the question wrong. i might need help with a diff one

shut venture
#

@gusty estuary do you mind tell me what book is that?

gusty estuary
#

@shut venture but it's a question made by my teacher

#

I'm confused on this one

shut venture
#

Ah ok

#

The questions seem cool.

gusty estuary
#

yeah he makes storylines and stuff like that

shut venture
#

I need to learn how to do those 😄

gusty estuary
#

haha

shut venture
#

It seems motivating to learn like that

silent plank
#

draw circles of radius 5 centred at those points

shut venture
#

@silent plank why radius 5?

silent plank
#

because the problem states that the killer is within 5 miles of them

shut venture
#

oh right i didnt see that

weak lichen
#

can you help me solve this one?

pearl finch
#

how do i solve this problem

#

i got it right but idk how to solve that shit

upper karma
#

how'd you get it right

#

but not know how to solve it

upper karma
pearl finch
#

@upper karma the teacher gave out the answer

upper karma
#

have they not given you the process

#

bruh moment

pearl finch
#

well they did but it got so confusing

#

i need it to be re-explained

#

I know RP is the altitude

#

but i forgot how to use it to solve for the rest of the triangle

upper karma
#

So PT is 12 less than SP right? just clarifying I know it says it there

pearl finch
#

yes

upper karma
#

alright

shut venture
#

Why not using the straight rectangle metric relationships?

pearl finch
#

whats that

shut venture
#

trying to find in english

pearl finch
#

not more formulas oh my god

upper karma
#

Better image

shut venture
#

thanks

upper karma
#

never heard of these so they can explain

shut venture
#

im not entirely sure its the solution

#

but ill have to write it

#

@pearl finch what does it mean

#

is it a 12?

pearl finch
#

what

#

bro my teacher never taught us this

#

plus my brain is shit at memorizing formulas

#

thats how the brain works iirc

weak lichen
shut venture
#

@frank pasturewa sin(25)=x/7

upper karma
#

e is PT

#

So just find every equations that includes e

#

and kinda mess around with em

frank pasture
shut venture
#

@pearl finch you dont need the relationships

upper karma
shut venture
#

sorry @frank pasture not that used to discord.

#

@pearl finch you can do triangle similitarity

upper karma
#

according to this

#

apply it here

fluid wasp
#

Can you help me find formula calculation ?

shut venture
#

Sorry i cant understand the image

pearl finch
#

Please

shut venture
#

what do you want to know

pearl finch
#

I still dont know how to solve this problem

fluid wasp
#

Better ?

#

i wanna know how i can get X if i know r1, r2, a, b

shut venture
#

that seems like sinusoidal function

#

@pearl finch use triangle similarity

pearl finch
shut venture
#

lets call SP as x so PT = x-12

#

so 8/x=x-12/8

pearl finch
shut venture
#

you can do either way

#

you just have to use the same order

pearl finch
#

U wont get the same answer if u flip the numbers around

shut venture
#

how come?

pearl finch
#

How would the algebra be the same if 8/x is equal to both x-12/8 to 8/x-12

shut venture
#

you have the flip

#

the other side too

#

x/8=8/x-12

pearl finch
#

Oh ok

pearl finch
shut venture
#

the dimensions given in the problem

pearl finch
#

No i meant whats your answer for it

shut venture
#

4

#

x=16

pearl finch
#

Oh

#

Nvm

#

Bruh why cant i get that

#

Wtf

shut venture
#

what do you mean

pearl finch
#

Do you need quadratic equation

#

can you show me how you got 4

#

Can you picture and show me

#

Yes you need quadratic equation

#

One of the answers is 16

#

-12 = 4

shut venture
#

its 16-12=4

#

the other answer is x=-4

#

but you can have it negative

upper karma
#

where are the four triangles? I mean I do see only two, one is the tiny
one on the left, and the other one, is the one that is subdivided, while
the rest are rectangles

https://imgur.com/Il97R3h <@&286206848099549185>

onyx cloud
#

those trapezoids to the right of the smallest triangle on the left make up bigger triangles

upper karma
#

I'm sorry I still do see only two and not four

onyx cloud
#

do you see it?

upper karma
#

oh, I'm an idiot, thanks

agile furnace
#

Name the single translation vector that can replace the composition of these three translation vectors: <2, 3>, then <–5, 7>, then <13, 0>.

#

<@&286206848099549185>

upper merlin
#

what happens when you translate using 2 vectors

#

the resultant translation vector is just the sum of the two vectors

#

for example going a miles north and b miles east, then going c miles north and d miles east, is the same as going a+b miles north and c+d miles east

#

so just add the 3 vectors

woeful shuttle
#

could someone help me with a geometry practice because I am struggling because I suck at circles

hardy kindle
#

hi can someone help me with my hw?
no. 19 and 20 only :D ty

upper karma
#

and what do you know what alternate exterior angles

#

q. 19

hardy kindle
upper karma
#

ok a pair of what angles

hardy kindle
#

transversal

#

uh

upper karma
#

yeah ok go on

#

what about them

upper karma
dark sparrow
#

@upper karma do not give out answers

dark sparrow
#

!

upper karma
#

wy

dark sparrow
slate lodge
small flume
#

i was thinking about this theorem

slate lodge
#

i did 2x-4=x+1

slate lodge
tender storm
#

i have similar problem with circles

slate lodge
#

yea ill try

tender storm
#

thank you

gray minnow
#

pls explain this relation to me

dark sparrow
#

what about it do you need explained?