#geometry-and-trigonometry

1 messages · Page 204 of 1

young hemlock
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ok

little osprey
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So what would it look like? (the formula)

young hemlock
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90 by 360

umbral snow
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You need the perimeter of a whole circle of radius 7, then multiply it by 3/4 since it's a 3/4 circle. That gives the three curvy bits

little osprey
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Don't give him the answer, try to make him understand

young hemlock
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yeah i dont mind

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i want to learn

umbral snow
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I wouldn't go as complicated as a radians formula

little osprey
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Wdym

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It doesn't need any radians

umbral snow
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Just make whole circles, then cut parts of them out by division

little osprey
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That's not how the perimeter works

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it needs the arcs and the sides

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Anyways...

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@young hemlock You still following?

young hemlock
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yeah

little osprey
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So um what do you get for the arc lenght?

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lenght*

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length*

young hemlock
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90 by 360?

little osprey
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yeah and if you keep that in the formula?

young hemlock
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90 by 360 . times 2 pi 7

little osprey
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Nice

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So what do you get?

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like the answer

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for that

young hemlock
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10.99557429

little osprey
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Nice

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And that x 3

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Cuz there are 3 arcs

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You got that step?

young hemlock
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ye

little osprey
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Then add 2x7

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And you're set

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for perimeter

young hemlock
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uh

little osprey
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Yeah?

young hemlock
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well

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the answer is 47.0 cm, 115 cm square

little osprey
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What did you get from the calculations

young hemlock
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461 point something

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wait hold up

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i messed up

little osprey
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2x7+270xpix7

young hemlock
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ok

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u were right

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i did times 14 by mistake

little osprey
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Then round that by 3 s.f

young hemlock
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also

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why do we add 2 times 7

little osprey
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Cuz there are two radius sides to add as well

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So you see the 3 arcs right?

young hemlock
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yeah

little osprey
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do you see the 2 radius's?

young hemlock
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2 radius sides...

little osprey
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that are besides the arcs

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Do you not see it?

young hemlock
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the curve?

little osprey
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Those sides

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The curves were calculated already

young hemlock
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oh

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ok

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👍

little osprey
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Awesome

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You can do area?

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Or...

young hemlock
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ill try

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ok can't figure it out

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@little osprey can u help

little osprey
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k

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whats the formula of a circle

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area

young hemlock
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pi r square

little osprey
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yeah

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so if it's a quarter

young hemlock
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divided by 4

little osprey
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what do you think it would be

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yeah

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and then there are 3 of those quarters

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so what would that become

young hemlock
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times 3

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OH

little osprey
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yeah

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lol

young hemlock
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i got it

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sry for caps xd

little osprey
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no worries

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Shows you have expressions

young hemlock
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lmao

upper karma
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any help much appreciated

Matt watches as a hot air balloon rises and comes to a stop at a height of 130 feet. The angle of elevation of the hot air balloon from where he is currently standing is 30 degrees. How far does Matt need to walk if he wants to stand directly underneath the balloon?

hallow smelt
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i think its 130sin60/sin30

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the 60 and 30 are degrees

hallow smelt
upper karma
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What’s his error?

astral hornet
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Do you know how to do an angle bisector construction?

upper karma
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$cos(5x)-cos(15x)=(3*sqrt(3)*tan(5x))/2$

somber coyoteBOT
upper karma
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Hmm

pallid cloud
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@upper karma his mistake is he considered CB=CD, and it is clearly not the case

lime flame
pallid cloud
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Metric relations exercise

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But if you could send a better image

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I can barely see

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@lime flame

lime flame
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oh srry

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can't at the momment

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ln is an altitude and klm is right

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and km is 16

pallid cloud
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I'll tell you what you should try

lime flame
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ok

pallid cloud
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For A see if $LM^{2}=MN×MK$

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It's called Euclid's theorem

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If it is verified

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Then LMK is right at L

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And the reciprocal is also true

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Anws

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For B the same thing

somber coyoteBOT
pallid cloud
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For B the same thing

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I guess B is correct

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$LM^{2}=12^{2}=144$

somber coyoteBOT
pallid cloud
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$MN×MK=9×16=144$

somber coyoteBOT
pallid cloud
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So B is correct

dark sparrow
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oh god two col proofs

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okay but actually it's not hard to go from AD = BC and AB = CD to ABCD being a parallelogram

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draw a diagonal, get two congruent triangles (by SSS), prove some angles equal to one another

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well like ok lemme make this more concrete

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triangles ABD and CDB are congruent

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angle ABD = angle CDB

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the triangles are congruent by SSS

young hemlock
dark sparrow
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what's holding you up?

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@young hemlock

young hemlock
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i dont understad

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how to do it

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its part of the arcs section questions

dark sparrow
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well ok so like

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you know what a clock looks like, right

young hemlock
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yes

dark sparrow
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well

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what curve does the tip of the minute hand follow?

young hemlock
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i dont know

dark sparrow
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imagine the minute hand of a clock

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how does it move as time goes on?

young hemlock
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clockwise

dark sparrow
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it rotates.

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so what curve does its tip follow?

young hemlock
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um

dark sparrow
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imagine the hand rotating

young hemlock
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ok

dark sparrow
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focus on its tip

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how does it move?

young hemlock
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it moves around

ember obsidian
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Shape

dark sparrow
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it moves along a ____

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fill in the blank

young hemlock
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circle\

dark sparrow
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great

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so the tip of the minute hand moves in a circle

young hemlock
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yes

dark sparrow
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so

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so if you follow the tip of the minute hand over a certain length of time (here 35 minutes)

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what curve does it trace out?

young hemlock
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a circle

dark sparrow
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not necessarily

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it takes an hour to go fully around the circle

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so what if we only track its movement for less than an hour

young hemlock
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so semicircle

dark sparrow
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no, not necessarily.

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that's if it was half an hour.

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it traces out a ___

young hemlock
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I don't know.

dark sparrow
young hemlock
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No

dark sparrow
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there's a special name for this kind of curve

young hemlock
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What is it called

dark sparrow
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that's what i should be asking you ;P

young hemlock
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ok

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perimeter

dark sparrow
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no

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you even mentioned the word i'm asking you for

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in this very conversation

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this curve is called an arc.

young hemlock
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Ok

dark sparrow
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honestly if you didn't know what that was then you should go review your basics

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bc you will not be able to do this exercise not knowing what an arc is

young hemlock
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Ok I got the answer

young hemlock
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can someone help me in this sum

dark sparrow
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what's holding you up here?

young hemlock
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well

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I'm trying to find the volume

dark sparrow
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that's what the problem is asking, yes.

young hemlock
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But I don't think I'm putting the correct values

dark sparrow
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how are you trying to find the volume?

young hemlock
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uh

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using the formula

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pi r square times height

dark sparrow
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what does that formula apply to?

heady urchin
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Ann I need help after this guy

dark sparrow
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ok

young hemlock
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oh i think i used the weong formula

dark sparrow
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no formula exists in isolation

young hemlock
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its for cylinder

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but this isnt cylinder

dark sparrow
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indeed.

young hemlock
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lemme try it with the other formula

heady urchin
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Ok ann

dark sparrow
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"the" other formula?

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sorry @heady urchin, we're not done here yet.

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@young hemlock what do you mean by the other formula?

young hemlock
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um

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area of cross section times length

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@dark sparrow would it be width times depth times height

dark sparrow
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i don't know, would it?

young hemlock
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i dont know thats why im asking you

dark sparrow
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try to answer the question yourself

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"width * depth * height" does give you the volume of a shape. what is that shape? does your pool have that shape?

young hemlock
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cuboid

dark sparrow
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and is your pool a cuboid?

young hemlock
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yes i think

dark sparrow
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are you sure about that?

young hemlock
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yes

dark sparrow
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you'd be wrong.

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the faces of a cuboid are all rectangles, but two of your pool's faces are trapezoids.

heady urchin
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Ann is there someone that I can msg I need help ASAP lol

dark sparrow
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i mean you can PM me i guess

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why the urgency though?

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@young hemlock are you still here?

blissful cedar
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The pool isn't at a constant depth also

dark sparrow
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...

young hemlock
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yes

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im still here

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ill move onto the next question since i cant seem to answer this one

dark sparrow
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as you wish.

upper karma
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@young hemlock I think I can help

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Or have you figured it out already

young hemlock
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@upper karma I asked someone else and he helped me

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No worries 👍

upper karma
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Okay

flint compass
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Why do you divide 2pi by the coefficient to get the period of sinusoidal function?

forest niche
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Help me 😭

dark sparrow
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what's holding you up here?

forest niche
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I’m just lost all around

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Where do I start?

dark sparrow
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ask yourself this:

  • What is this thing in front of me?
  • What am I asked to do with it?
  • What can I use to do that?
forest niche
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It’s a rhombus?

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But it’s cut weird?

dark sparrow
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no, it is not a rhombus. its sides aren't known to all be equal to one another

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it is, however, a parallelogram

forest niche
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OH

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Bxh?

dark sparrow
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you've asked yourself the first question but showed no indication that you have asked yourself the other two

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and i'd like you to spell out your answer to the second question before blurting out a formula without even saying what that formula does

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(also, don't use x for multiplication, for god's sake!)

forest niche
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Uh the 11 is the base?

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And the 6 is the height

dark sparrow
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please read what i am saying

forest niche
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Idk you’re confusing me right now

dark sparrow
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you've answered "What is this thing in front of me?"

forest niche
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Ok

dark sparrow
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what i'm now asking you to do is to answer the next question on that little list i sent

forest niche
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I need to find the area

dark sparrow
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okay, good

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and now the third question

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"What can I use to do that?"

forest niche
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And use base times height?

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Because it’s a parallelogram

dark sparrow
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sure, you can use the formula that states the area of a parallelogram is equal to its base times its height.

forest niche
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Okay, thank you!

dark sparrow
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you're welcome

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there are two things you need to find out no matter what problem you're doing

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what to do, and how to do it

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in this problem, the former was harder than the latter

forest niche
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Ok I appreciate it

fiery iron
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If area of polygon P1 constructed from center of circles C1 is greater than that of polygon P2 constructed from another set of circles C2, and each circles is having same radius, does it guarantees that area( C1 ) > area( C2) if area(P1) > area (P2)

upper karma
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how to solve the second question?

tropic shard
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When in doubt, quadratic equation.

upper karma
#

@tropic shard elaborate on that pls ;-;

valid agate
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@paper verge Please don't ghost ping

upper karma
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So that's who did that

valid agate
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I've got a pounce on mod pings

upper karma
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<@&268886789983436800> maybe you guys can answer my question? i really need help rn

native night
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don't ping mods for hw help

upper karma
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oh sorry i didn't know that

tropic shard
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To solve for x for x²-7x-8=0, you'd use the quadratic equation for A=1, B=-7, and C=-8

upper karma
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@tropic shard sorry thats the third question

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i said second

dire rampart
faint orchid
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Can someone help me figure out this identity? I think it has something to do with Euler's Identity but not sure

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could be overthinking it

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Ignore the 2 and 1 on the far left, those are just initial conditions for a discrete time system

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Nevermind, I think I understand. Its just basic unit circle manipulation

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Looks like the combination of both the sin and cosine terms yield the -pi/6

oak minnow
#

Can someone help me with trig

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like the basic one

dark sparrow
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you don't need trig for this

oak minnow
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waddaya mean

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im stuck

dark sparrow
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you're overthinking this, surely.

oak minnow
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I used the cosine rule

dark sparrow
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oh my god what

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look

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this is a right triangle.

oak minnow
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nvm

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tangent

dark sparrow
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no, even simpler

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you know two of its sides and want the third.

oak minnow
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yea

dark sparrow
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there's a theorem which relates the three sides of a right triangle

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very famous

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and you definitely know what it is

oak minnow
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ye

dark sparrow
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yeah so what is that theorem

oak minnow
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pt

dark sparrow
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pt?

oak minnow
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its a shorter way of saying it

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pythagoras theorem

dark sparrow
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yes

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so

oak minnow
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or however you spell it

faint orchid
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If you know the theorem why aren't you able to deduce the answer from the theorem?

somber coyoteBOT
oak minnow
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yeah

dark sparrow
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yeah so

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what's the problem

faint orchid
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You have A and C

oak minnow
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like the answer its giving me in in a square root

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.help

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,help

somber coyoteBOT
#

A brief description and guide on how to use me was sent to your DMs! Please use ,list to see a list of all my commands, and ,help cmd to get detailed help on a command!

faint orchid
#

The answer is allowed to be in square root form, not every triangle has perfect sides with integers.

#

in this case you should have the formula to find the side B

oak minnow
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I dont understand them though

dark sparrow
#

you don't understand what

oak minnow
#

I'd like it in the sin, cos, tan form

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√35 m

faint orchid
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$b = \sqrt{6^2 - 1^2}$

dark sparrow
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6^2 - 1^2 @faint orchid

oak minnow
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how'd u type that out so fast

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jesus

dark sparrow
#

the answer is sqrt(35) m

faint orchid
#

Ah yeah my bad

dark sparrow
#

what more do you want

somber coyoteBOT
faint orchid
#

What do you mean by you want it in 'sine, cosine, tan' form?

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it's asking you for the length of the edge.

somber coyoteBOT
oak minnow
#

ah

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how tf did u do that

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I need to learn those commands

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I know but

faint orchid
#

Check the resources tab for a LaTeX cheat sheet

oak minnow
#

wait

faint orchid
oak minnow
#

6^2+1^2

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is 37?

faint orchid
#

its minus, I made a mistake and corrected.

oak minnow
#

not oh

faint orchid
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6^2 - 1^2

oak minnow
#

so we just put the question the form of a^2+b^2=c^2

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?

dark sparrow
#

what

oak minnow
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nvm

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would it be 1/2ah

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wait

dark sparrow
#

again

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this is a right triangle

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and you know two of its sides

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and you want the third...

oak minnow
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i already did that one

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but

dark sparrow
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but what

oak minnow
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i have another question

dark sparrow
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make a picture!

oak minnow
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I did

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its not very good

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help

dark sparrow
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now it's trig time

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this is a right triangle

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you know a side and an angle

oak minnow
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yes

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how do i find the third

dark sparrow
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i mean there are two sides to be found but those are different subproblems

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are you able to find AB?

oak minnow
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nah

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wait

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wouldn't it be 3^2+3^2

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sqrt of that

dark sparrow
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why?

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you don't know if AC = 3

oak minnow
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how do i find AB

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help

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plz

dark sparrow
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well you said you were doing basic trig, didn't you?

oak minnow
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could u please just explain it out

dark sparrow
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sorry, i was having lunch.

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@oak minnow still here?

oak minnow
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yes

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I was waiting for a reply

dark sparrow
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k

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so

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how familiar are you with sin, cos and tan

oak minnow
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a fair bit

dark sparrow
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well

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do you know what they are

oak minnow
#

what

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yes

dark sparrow
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well then

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what are they

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if you answer this question, it may help you solve the problem

oak minnow
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what do you mean

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sine, cosine and tangent

dark sparrow
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you said you knew what these are

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state their definitions to me

oak minnow
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oh

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for the question

dark sparrow
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no, forget about the question for a moment

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tell me what sin, cos and tan are

oak minnow
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i just use the sohcahtoa thing

dark sparrow
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i mean. okay, yeah, that's a mnemonic to help remember the definition

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ok

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alright

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so back to the problem

oak minnow
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ya

dark sparrow
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you know BC and you want AB, and the one angle you know is angle A

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which of sine, cosine and tangent is it possible to use here?

oak minnow
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erm

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cosine

dark sparrow
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why?

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(i'm going to ask you "why" a bunch. you gotta be able to explain what you do.)

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so, why cosine?

oak minnow
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because we need to find

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idk

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i give up

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im not good at trig

dark sparrow
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okay look

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this is just logic

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common sense

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don't give up

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you were mere inches away

oak minnow
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ok since we have both sides BC we need to find AB

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and to do that

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we need to find the sides

dark sparrow
#

no, no

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look

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there's two sides you care about

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you care about BC because it's the only side you know

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and you care about AB because you want to find it

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does that make sense?

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don't overthink it.

oak minnow
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yes ok but

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how do I find the other side

dark sparrow
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well

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wait

oak minnow
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the length of

dark sparrow
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what other side

oak minnow
#

the ladder

dark sparrow
#

well

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this is where trig comes in

oak minnow
dark sparrow
#

so you know the mnemonic "SOH CAH TOA"

oak minnow
#

eah

dark sparrow
#

what does it stand for?

oak minnow
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ok

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sine = opposite/hypotenuse, cosine = adjacent/hypotenuse , tangent= opposite/adjacent

dark sparrow
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okay good

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so

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is BC the opposite, the adjacent, or the hypotenuse?

oak minnow
#

adjacent

dark sparrow
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are you sure?

oak minnow
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i think so because its adjacent the opposite?

dark sparrow
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adjacent means "next to"

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next to the angle, in this case

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BC is the opposite

oak minnow
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oh

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yeah

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cause of the angle

dark sparrow
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yes bc the angle is at the center of all this

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so now

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is AB the opposite, the adjacent, or the hypotenuse?

oak minnow
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hyp

dark sparrow
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okay

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so you have the opposite and the hypotenuse.

oak minnow
#

sine

dark sparrow
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great

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are you able to write this out?

oak minnow
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so would it be

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3/sine26

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6.84

dark sparrow
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it = what?

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,w 3/sin(26°)

somber coyoteBOT
dark sparrow
#

...yes, AB = 6.844 m

oak minnow
#

how you have u done it

dark sparrow
#

that's exactly how i would've done it. this is one of those problems where there really is only one solution

oak minnow
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thanks ann

upper karma
dark sparrow
#

is your calculator in degree mode or radian mode

upper karma
#

Rad

dark sparrow
#

put it into degree mode.

upper karma
#

It's on

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I'm not sure how to find the c and b if I only have the 67.2

dark sparrow
#

...wait ok what

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lemme read the problem again

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are you given only a = 67.2?!

upper karma
#

Yup

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The C is just 90°

dark sparrow
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together with the right angle, that means you only have two elements in the triangle

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you need three to solve it

upper karma
#

Unless if i just click "there is not enough information to solve it"

dark sparrow
#

there is not enough info.

upper karma
#

Ah i figured

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I have another question that's more simpler, but i keep getting it wromg again

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And I'm not sure what i did wrong
I put TAN 32.7/18.6

dark sparrow
#

you do not want tan(32.7/18.6)

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what does inside the tan would be an angle

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you want the inverse tan.

upper karma
#

Ohh

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60.4

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Hm i typed it out and it wasn't right

dark sparrow
#

okay, sorry, my vision is a bit blurry today

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you were finding the wrong angle

upper karma
#

Oh oof

oak minnow
#

<@&286206848099549185>

keen aspen
#

Draw a right triangle with theta being 16 and the height being 400

oak minnow
#

yeah lol thanks man

upper karma
#

trigonometry?

dark sparrow
#

@oak minnow how did you find XY?

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(don't tell me the value, bc i don't care about it. just tell me how you found it)

oak minnow
#

dont worry, i did't read the question properly

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so what I did was

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use the sine rule

dark sparrow
#

uh huh

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law of sines

oak minnow
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10/sine50/sine70

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if u know what i mean

dark sparrow
#

...okay, you should never write "a/b/c" like that

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did you mean (10/sin(50°))/sin(70°)?

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or did you mean 10/(sin(50°)/sin(70°))?

oak minnow
#

something like that

dark sparrow
#

then why did you put that first slash?

oak minnow
#

idk

dark sparrow
#

$\frac{10 \sin(50^\circ)}{\sin(70^\circ)}$

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oof

oak minnow
#

yeah

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i still dont understand the synbols

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$

somber coyoteBOT
oak minnow
#

$

dark sparrow
#

oh $ just tells the bot i want to render a formula

oak minnow
#

, w $\frac{10 \sin(50^\circ)}{\sin(70^\circ)}$

somber coyoteBOT
oak minnow
#

, ask $\frac{10 \sin(50^\circ)}{\sin(70^\circ)}$

dark sparrow
#

yeah WA gets confused lol

somber coyoteBOT
dark sparrow
#

,w (10 sin(50°))/sin(70°)

somber coyoteBOT
oak minnow
#

yeah

#

thats the one

#

are u a maths teacher

#

(12 sin(38°))/sin(90°)

#

, w (12 sin(38°))/sin(90°)

somber coyoteBOT
oak minnow
#

the answer is meant to be 9.46

dark sparrow
#

first off this is a right triangle & you would've done better to recognize that

#

and second you used the law of sines correctly but found the wrong side

#

@oak minnow

oak minnow
#

yes

dark sparrow
#

...??? what are you saying "yes" to?

oak minnow
#

the second point you made

#

so tell me which side i need tofind

dark sparrow
#

if you look at the picture

#

the side to be found is literally marked

#

yknow, you won't always be able to get others to read shit for you

oak minnow
#

woah ok

#

cant i just put in the question in WA and get an answer

#

but idk how to do that

dark sparrow
#

no, you cannot

#

consider thinking

#

you are definitely able to do that question, if only you apply some mental effort

oak minnow
#

i am but i still dont understand :((

dark sparrow
#

this is a right triangle

#

do you understand that?

#

@oak minnow

oak minnow
#

Yes

#

I drew a picture of it but I drew it tilted

#

as a right triangle

#

with the points

dark sparrow
#

well

#

okay

#

this is a right triangle

#

so the SOH CAH TOA mnemonic applies

oak minnow
#

sine rule

dark sparrow
#

?

oak minnow
#

but we don't know the opposite ?

dark sparrow
#

you care about two sides: XY and YZ

#

what are they, in relation to angle Y?

oak minnow
#

right angles

dark sparrow
#

that makes zero sense

#

how can a side be an angle

#

please read what i am saying

oak minnow
#

yeah I'm

dark sparrow
#

i mean first off this is the geometry channel

#

and second i'm not exactly sure whether or not you're shitposting rn

#

and third, you should get a pingable nickname

#

???????

keen aspen
#

@upper karma can you not

dark sparrow
#

<@&268886789983436800>

paper mauve
#

@upper karma is everything okay? is there something I can assist you with?

twin heron
#

@upper karma stop

keen aspen
#

Just bean him

twin heron
#

fair

paper mauve
#

im kinda interested to see where this leads tho

dark sparrow
#

beaned

twin heron
fair raven
dire rampart
oak minnow
#

help

oak minnow
#

ok, or not

halcyon coyote
upper karma
#

would 1 and 6 be complimentary

#

No, complementary angles equal 90. 1 and 6 are more than 90 degrees

empty trout
#

2 and 6 would be complimentary

upper karma
#

so 1 and 6 is obtuse

#

yeah

#

A: angle 1 and angle 4 Strike Reset
B: angle 1 and angle 6 Strike Reset
C: angle 3 and angle 5 Strike Reset
D: angle 3 and angle 6

#

I mean out of these

#

its not a

#

not 3 and 6

#

either 3 and 5 or one and 6

#

3 and 5

empty trout
#

since 1 and 4 are vertically opposite angles, that means that 4 is 90 degrees, making 3 and 5 complimentary

upper karma
#

3 and 5 are also acute

#

so you can assume they add up to 90 deg

#

ohhh so they are 90 degrees and acute because both angles are touching each other

#

they are touching each other and their angles form a complementary angle

#

alright

upper karma
#

Beth leaned a ladder against her house, as shown below.

Figure not drawn to scale.

#

37° Strike Reset
B: 90° Strike Reset
C: 127° Strike Reset
D: 180° Strike Reset

#

180-53

#

this 180

#

-53

#

127

#

yep

#

does anyone know the formula for height of a cone

#

$V = \dfrac{1}{3}\pi r^2 h \
3V = \pi r^2 h \
\
\dfrac{3V}{\pi r^2} = h \
\therefore h = \dfrac{3V}{\pi r^2}$

#

.

Enter the answer only. Use only numbers. Do not use letters.

Oliver pours 141.3 cubic centimeters of water into a cone-shaped cup.

When he stops pouring, if the water at the top of the cup forms a circle with a diameter of 6 centimeters, the height of the cone is

#

so radius is 6 right

somber coyoteBOT
upper karma
#

6 divided by 2 is 3

#

yes

#

use the formula I gave to solve for height

#

ok

#

btw thats the pic

#

Oliver pours 141.3 cubic centimeters of water into a cone-shaped cup

#

IDk what the number is used for tho

#

only problem

#

I got 1331.72Cm

#

can you check that to see

#

sure

#

alright

#

R=3

#

does it want it in terms of pi or an exact answer

#

if it wants an exact answer, what value of pi is it asking for

#

that what it says

#

ok

#

I got

#

$47.1 \pi$

somber coyoteBOT
upper karma
#

that was the question btw

#

are you asking what values to substitute in?

#

Well I know R is 3

#

but idk H

#

its asking for the height of the cone

#

@upper karma

#

$\text{The Formula for the Height of the Cone is:} \
\
h = \dfrac{3V}{\pi r^2}$

somber coyoteBOT
raw prism
upper karma
#

$\tan^2(2x) = \dfrac{1-\cos(4x)}{\cos(4x)+1} \
\cos(2x) \left(\dfrac{1-\cos(4x)}{\cos(4x)+1}+3 \right)+3 = 0$

somber coyoteBOT
upper karma
#

$\dfrac{\cos(2x)-\cos(2x)\cos(4x)}{\cos(4x)+1}+3 \cos(2x)+3$

somber coyoteBOT
upper karma
#

$\dfrac{\cos(2x) \left(1-\cos(4x) \right)}{\cos(4x)+1}+3 \cos(2x)+3$

somber coyoteBOT
raw prism
#

so i can multiply the 2x first and then the cos?

upper karma
#

no, you multiply the 2x with the cos

pallid cloud
#

Abdullahsz1, it's cos(2x) not 2x

#

It's not space between them

raw prism
#

ok

pallid cloud
#

My first tought was to write tan^2 as sin^2/cos^2

#

Then multiply by cos2x

raw prism
#

yea thats what i did but no work

pallid cloud
#

Then write sin^2 as 1-cos^2

#

Then multiply the two members of the equality by cos2x

raw prism
#

also why did you add a 1 on the bottom shouldnt it just be cos^2?

pallid cloud
#

Lemme write on a piece of paper

#

2 mins

raw prism
#

kk np

upper karma
#

or you can substitute the 2x as a variable and then add in the 2x

raw prism
#

shouldnt the for cos on top and on bottom be to power of 2 since tan is also to power of 2?

pallid cloud
#

Yes it should

raw prism
#

,rotate 90

pallid cloud
#

,rotate 270

somber coyoteBOT
pallid cloud
#

This is an equivalence as long as cos(2x) is different then 0

#

To not divide by 0 somewhere

#

And to not multiply by 0 to be a double implication

raw prism
#

wait wouldnt it be to power of 3 when you multiply the cos^2 (2x) by cos(2x)

pallid cloud
#

@raw prism where ?

raw prism
#

2nd to 3rd step

pallid cloud
#

Where do you see cos^2 that I multiplied by cos ?

#

I didn't

oak minnow
#

hi

raw prism
#

when you multiply the first part (1-cos^2 (2x)/cos^2 (2x)) by cos(2x)

pallid cloud
#

I didn't

#

What I did is

#

$\frac{a+b}{c}=\frac{a}{c}+\frac{b}{c}$

somber coyoteBOT
pallid cloud
#

$c\neq 0$

somber coyoteBOT
raw prism
#

yea but you still have to multiply them with cos 2x casue they are in the paranthesis

pallid cloud
#

What paranthesis bro

#

The parenthesis are for cos

#

$\cos(something)$

somber coyoteBOT
pallid cloud
#

Do you want a version without parenthesis for cos, sin and tan
Ok

raw prism
#

yea its cos(2x) times that something right?

#

in the 2nd to 3rd step you only multiplied the 3 by cos(2x) not the other stuff

pallid cloud
#

I'll send a better pic

#

1 min

raw prism
#

k sorry im not understanding it properly

pallid cloud
#

,rotate 270

somber coyoteBOT
pallid cloud
#

,rotate 270

somber coyoteBOT
raw prism
#

oh ok i get it now you multiply before turing the sin^2 into 1-cos^2

pallid cloud
#

This is true as long as $\cos(2x) \neq 0$ \
For the 2 equations to be equivalent

somber coyoteBOT
pallid cloud
#

Yes

raw prism
#

i suck at math bigtime so thanks a lot

pallid cloud
#

Basically all of us do

raw prism
#

yea i wanted to do engineering or something like that but prob gonna move to a different field cause math is a biatch

pallid cloud
#

Nah maths is good

#

Don't look at this way

raw prism
#

yea i know but i cant understand it

pallid cloud
#

It is the easiet thing believe me

raw prism
#

its really fun when i understand it I realized that but idk why i spend so much time practicing it but like in 2 weeks its all gone from my brain

pallid cloud
#

We all forget don't worry

#

Even the biggest mathematicians

#

A little bit of practice to get better

#

And most importantly understand what you're doing

raw prism
#

well thanks i'll keep trying for now

pallid cloud
#

You're not asked to be Gauss
But you're asked to understand and practice

#

Yes always try

oak minnow
pallid cloud
#

Why

#

What you don't understand

oak minnow
#

howd they get from .5071 to 30.47

pallid cloud
#

Sine inverse

#

On calculator

#

Shift sin

oak minnow
#

o

pallid cloud
#

Or $sin^{-1}$

somber coyoteBOT
oak minnow
#

sin^-1()

#

yeah

#

ok

pallid cloud
#

Ye

#

Do you know why we have two possibilities ?

oak minnow
#

so just put $sin^{-1}{0.5071}

#

$sin^{-1}{0.5071}

#

$sin^{-1}{0.5071}$

somber coyoteBOT
pallid cloud
#

Yes

#

But it gives you one answer I guess on calculator

oak minnow
#

yeah

pallid cloud
#

We have 2 answers, because $\sin(\alpha)=\sin(180°-\alpha)$

somber coyoteBOT
oak minnow
#

yeah

#

it would be 180-30.47

pallid cloud
#

Yes

oak minnow
#

=149.13142

#

or something

#

that would be the slope of the angle ?

pallid cloud
#

?

oak minnow
#

nvm

#

i didn;t word it correctly

pallid cloud
#

Tell me what you mean

oak minnow
#

wouldn't 149 be the angle

#

of Z

pallid cloud
#

2 angles are possible
30.47...
And 149.53...

#

Z could be both

oak minnow
#

i

pallid cloud
#

They draw an image for a better explanation

oak minnow
#

hmm ok, will you be on later on today?

#

I might need your assistance

#

like in an hour or less

pallid cloud
#

Actually no, bc it's 1:36 am

oak minnow
#

oh gawd

#

in America

pallid cloud
#

I want to sleeeepppp
Yeah like 7 hrs less

oak minnow
#

Australia is 8 36 am

#

ok

pallid cloud
#

No me not America

oak minnow
#

you should go to sleep

#

europe?

pallid cloud
#

Asia, Lebanon

oak minnow
#

oh

pallid cloud
#

I guess we're gmt+3

oak minnow
#

yeah

#

we are gmt

pallid cloud
#

If you like, I'll be on like for 8 hrs from now

oak minnow
#

aest

#

yeah sure

#

ok gn

#

yoi should get some sleep

pallid cloud
#

Thanks

oak minnow
#

w

pallid cloud
#

Yes I will, now!

oak minnow
umbral snow
#

Use sin law to get angle B, then the sum of the angles is 180

oak minnow
#

yes but I keep getting different answers

valid pike
#

Isn't it just 99.25°

upper karma
#

What Baynex said

steady sleet
#

\🅱aynex*

#

wait

upper karma
#

do this

somber coyoteBOT
oak minnow
#

@valid pike yeah its 98.16

#

but how did u know

oak minnow
#

<@&286206848099549185>

dark sparrow
#

what is holding you up?

halcyon coyote
oak minnow
#

I dont get it

dark sparrow
#

show your work

oak minnow
#

so

#

can you just tell me on how to do it rather than asking me to "show work"

dark sparrow
#

no, i want to see what you are doing so that i can see where you messed up

oak minnow
#

ok wait

#

it will take a while cause i'm gonnatype it up

#

on WA

#

$8sin(108){frac}/9

#

what

#

wait

#

i'll just show you on paint

#

it'll be easier i guess

#

@dark sparrow

#

yeah so aha

dark sparrow
#

108°?

oak minnow
#

oh w8

dark sparrow
#

where on earth did you get 108° from?

oak minnow
#

so i did something like this

#

@dark sparrow

dark sparrow
#

...and?

oak minnow
#

so what did i do wrong

#

besides from everything here

dark sparrow
#

so far, you didn't

oak minnow
#

o rlly

#

the answer is meant to be 98.16

#

but idk how they got that

#

180-33.18

#

doesn't equal to 98

dark sparrow
#

why are you subtracting 33.18 from 180?

oak minnow
#

because of the sine rule?

torpid mirage
#

So you are trying to find theta?

oak minnow
#

yea

dark sparrow
#

because of the sine rule?
?????

#

here

#

you found that angle B = 33.18° @oak minnow

oak minnow
#

angle b is the longest side right?

dark sparrow
#

reread the message you just sent.

#

it doesn't make any sense. how can an angle be a side?

#

don't overthink this

#

you know two of the three angles in your triangle.

upper karma
#

Don’t be so hard on him

dark sparrow
#

how am i being hard

#

do you know how to find the third angle in a triangle given the other two? @oak minnow

torpid mirage
#

Your value for B is incorrect.

oak minnow
#

the angle - 180

torpid mirage
#

sin (38°) / 8 = sin (B) / 9 (Sine rule)
B = sin^-1 [9 sin (38°) / 8] = 43.838 (Inverse of sine)
Theta = 180° - 38° - 43.838° = 98.162° (Interior angles of a triangle)

dark sparrow
torpid mirage
#

Isn't it 9/8?

dark sparrow
#

wait yes

#

yes it should be 9/8 shit

#

i had that before

oak minnow
#

wait

torpid mirage
#

The angle opposite the side is used for sine rule.

oak minnow
#

why would it be 9/8

torpid mirage
#

9cm is opposite angle B.

dark sparrow
#

sin(38°)/8 = sin(B)/9

#

isolate sin(B)

#

multiply both sides by 9

oak minnow
#

ok

torpid mirage
#

Is there any difference in the arcsin and sin^-1 function?

dark sparrow
#

@torpid mirage no, and in fact desmos supports both notations

oak minnow
#

whats

#

a

supple abyss
torpid mirage
#

The angle. In this case, angle B.

#

You can use practically any variable.

oak minnow
#

oooo I see

#

180-38-43.1622...

dark sparrow
#

you should've been able to come up with the second line yourself, but evidently you're shaky on the very basics of geometry

oak minnow
#

true

#

i cant argue there

dark sparrow
#

well then

#

go back to the basics

#

and make sure you have those down cold

oak minnow
#

This is right?

dark sparrow
#

yes

torpid mirage
#

Yes! Nice!

oak minnow
#

phew thanks

oak minnow
#

How do I do this?

#

it doesn't state whether its a right triangle

dark sparrow
#

you cannot assume a triangle is right unless it is known to be right

#

make diagrams

oak minnow
#

i'll use the law of cosines, maybe that'll work

dark sparrow
#

i mean...

#

you've given five subproblems but no indication of which one you are stuck on

#

the law of sines and the law of cosines will both probably be needed to solve this problem, each in its own circumstance

oak minnow
#

yeah...

torpid mirage
#

For all of them, sin (A) / a = sin (B) / b = sin (C) / c. So you need to find a, b, c, A, B and C. In (a), a, B and C are given. A can be found using 180° - B - C. Now that you have 3 angles and 1 side, you can use sine rule to get the other two sides.

#

Every single question gives you 2 angles and 1 side, which is enough information to get the 3rd angle and get all of the sides using sine rule only.

acoustic fiber
#

The difference in the measures of two complementary angles is 12°. Find the measures of the angles?

dark sparrow
#

do you know what it means for two angles to be complementary?

acoustic fiber
#

yes

dark sparrow
#

what, then

acoustic fiber
#

their sum forms 90°

dark sparrow
#

uh huh

#

so now

#

you have two angles; their sum is 90° and their difference is 12°

#

what must they be

acoustic fiber
#

I could do trial and error method

dark sparrow
#

don't

#

that's gonna take you too long

acoustic fiber
#

correct

#

let one angle be x

dark sparrow
#

ok

acoustic fiber
#

then x+x=90

dark sparrow
#

huh?

acoustic fiber
#

sorry

dark sparrow
#

no, this is not correct. in writing that, you just assumed the two angles would be equal

acoustic fiber
#

yeahh correct

#

ok I will think about it

dark sparrow
#

ping me when you come up with something

acoustic fiber
#

sure

#

I've no clue, how I did that lol, I was just writing down the points and it just hit me and this is the result

#

@dark sparrow

dark sparrow
#

i mean this is basically exactly what i expected of you

acoustic fiber
#

did I do something wrong?? @dark sparrow

dark sparrow
#

no

#

on the contrary

#

this is exactly right