#help-49

1 messages · Page 48 of 1

lavish venture
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ahh

keen hill
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Ap covers alot of the same content

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some things left out

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but

last slate
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Physics ?

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No physics in high-school?

lavish venture
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no there is

keen hill
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there is physics at mine if you choose to do it

lavish venture
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yea

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it’s optional

keen hill
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its a chemistry bio sequence or physics

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usually

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for us anyways

lavish venture
#

my school only offered 2 of the ap courses which basically consisted of regular mechanics

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i had to self study for e&m

last slate
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lol they teach us first semester of physics course at a standarduni in like 11th grade of high-school

keen hill
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i also took it at college since they skip the calculus

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or my school doesnt have calculus phyiscs yet

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just algebra based

last slate
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Wtf

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Lmao

lavish venture
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they only had physics 1?

keen hill
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its a testing space problem

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we have physics 1 and 2

lavish venture
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ahh

keen hill
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but there aren't enough rooms to conduct the exams

last slate
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Physics without calculus

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Lol

lavish venture
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my school had physics 1 and physics c mech

last slate
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Electrodynamics ?

lavish venture
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i took physics 2 and physics c e&m independently and just ordered the exam

lavish venture
keen hill
lavish venture
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they don’t offer it

keen hill
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we have ENM but not with calculus!

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"E&M"

lavish venture
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yea physics 2 e&m is a joke

keen hill
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its dumbed down

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as hell

lavish venture
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lol

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e&m requires calc really

keen hill
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it does

last slate
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Lmao knowing elementary integrals even I am struggling with e and m as you require alot of vector calculus and ideas like divergence I nit

keen hill
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the teacher at my school teaches it with calculus to the students who are prepared

last slate
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I have no idea how you guys had e and m in thay

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That

lavish venture
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yea how are you doing that before integral calculus??

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i mean

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a lot of it is just symmetry

keen hill
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physics loves symmetry!

lavish venture
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so you don’t need to do much integration at all

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but

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still there are some problems

last slate
keen hill
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yea

last slate
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Because jee physics is impossible without calculus

keen hill
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the thing with algebraic physics is it's just all very conceptual and symbolic in nature

lavish venture
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probably didn’t need the last two words

full quest
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Have y’all guys challenge csat once

lavish venture
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what’s csat

keen hill
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is that the korean one

full quest
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Ye

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One of the hardest ones

keen hill
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have never done it

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what does it cover up until?

lavish venture
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oh isn’t the english part hard?

full quest
lavish venture
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never seen it then

keen hill
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if it's just calculus and anything before it should be fun

last slate
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We have pretty good use of calculus in e and m

keen hill
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looks about right

lavish venture
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yea this is fun

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i thought gauss’ law was cool

last slate
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Stretches way beyond our math syllabus

last slate
keen hill
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physics does that in american university too

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your physics course almost always outpace your math

last slate
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Unintuive to me it's only mathematically beautiful to me nothing more

lavish venture
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yea but with symmetry E is always just constant and gets pulled out of the integral

last slate
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No

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It depends on your choice of gaussian surface

lavish venture
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well yes

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but if you choose it appropriately

last slate
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For all points

lavish venture
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the problem should work out well

last slate
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On surface

last slate
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They give arbitary things

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You have to choose some surface then compute the field

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Shits wild

lavish venture
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lol in the ap course we had three scenarios and they were all simple

last slate
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how is that advanced course if you had simple things

lavish venture
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🤷🏼‍♂️

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don’t let the name fool you

keen hill
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in reality the courses are meant to expose you to the topics before college level courses

last slate
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I thought kids who take college courses in us are smart prodigies

keen hill
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even ap courses

last slate
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💀

lavish venture
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probably half of the kids take ap courses

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atleast in my area

keen hill
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AP physics curriculums focus more on conceptual understanding over solving problems

lavish venture
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but not all of the more "difficult" ones

keen hill
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and in college it depends on your teacher

last slate
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Like

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Won't solving problems

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Do the same thing

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Enhance conceptual understanding

keen hill
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i mean it would definitely enhance it, but you'll be covering the same things much more in depth in upper division mechanics and e&m with new concepts

last slate
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As the math used will be elementary and known the only challenge would be to conceptually imagine the physical situation

keen hill
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well many times you'll be solving problems purely symbolically with no real numbers

last slate
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It was nice

keen hill
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taylor's is an amazing book

lavish venture
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this is a sample problem from the exam

last slate
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Yeah I read some things which I didn't get

lavish venture
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for e&m

last slate
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From Taylor like damped oscillations

last slate
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We have this in high-school

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Classes

keen hill
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yea

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for free response anyways

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AP c is definitely

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tamed

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in terms of mathematical complexity

lavish venture
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the mcq is harder

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i took both physics c classes this year

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the frqs were so much easier

keen hill
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yup

lavish venture
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and much more time friendly

keen hill
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they don't ask for really precise solutions on frqs all the time

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so its nice

lavish venture
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each mcq was a paragraph long lol

last slate
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aaa

keen hill
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its standardized

lavish venture
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some took up the whole page

last slate
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you guys be chillin

keen hill
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for my intro mechanics course

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it was

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not so nice.

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and honestly

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I'm not sure I learned more having ugly numbers

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because when you have to deal with the number spaghetti it turns into alot more computation and less conception challenge

lavish venture
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how many courses did you take at a local college?

keen hill
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I have 40 semester credits

lavish venture
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jesus

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none of those are ap?

keen hill
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well I have AP credits too

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but its for

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more trivial courses

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none of those are AP though no

lavish venture
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ok that’s more reasonable

keen hill
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my aps are humanities

lavish venture
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oh

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nevermind

last slate
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Jee math is comparatively easier

keen hill
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I am not sure if that's true

last slate
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Compared to other subjects

keen hill
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ohhh

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yea

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that makes sense

last slate
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no seriously it's much less complicated like you won't get anything new

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Lol

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Let me show you ques

keen hill
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I don't think we are a neccesarily good representation of the US population either

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it appears (I think) that both knief and I are from higher socioeconomic areas

last slate
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You mean you guys are rich and go to better schools

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?

keen hill
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yup

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probably not incredibly rich

last slate
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Here like rich and middle class go to same schools cause the middle class wants their kid to go to a rich so he will be rich lol

keen hill
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but in the top 25%

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or like

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40%

last slate
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poor go to poor schools

keen hill
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that is also pretty much the same here

keen hill
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I am from socal!

lavish venture
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yea

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makes sense

keen hill
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these problems seem pretty fun

last slate
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They are fun

keen hill
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in reality i don't know how

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useful

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or like

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conceptually reinforcing they are

last slate
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Not useful lol

keen hill
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but they are good ways to test your ability to apply them

last slate
lavish venture
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a lot of these don’t seem bad at all

last slate
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You won't get such things often studying physical phenomenona

keen hill
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yea

last slate
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They're not meant to be "useful" is what I mean

keen hill
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yea of course

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well

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when I say "useful"

lavish venture
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this is JEE advanced?

keen hill
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i don't mean practical in everyday life

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I just mean useful in learning the concept

last slate
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yeah

keen hill
lavish venture
keen hill
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fun!

lavish venture
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so yes

keen hill
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will also be a fellow

lavish venture
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i’m taking calc 3 and linear algebra this summer

keen hill
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applied math major

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applied math/cs

lavish venture
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i put that down

keen hill
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I never planned to even be a math major

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but my linear algebra professor changed that last semester

last slate
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lol

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I will be a physics major

lavish venture
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you want to do research?

keen hill
keen hill
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for a little bit anyways

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oh

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you were talking to him

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but

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i'd assume so yes

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too

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for him

lavish venture
keen hill
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he did inspire me

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amazing teacher

last slate
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I will research privately maybe lol

keen hill
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came out of stanford Ph.D program

lavish venture
keen hill
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yes

lavish venture
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damn

last slate
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Wow you guys have inspiring teachers irl lol I am only inspired by the great American and european minds nothing more

last slate
lavish venture
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oh i don’t have any good teachers lol

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my teachers are terrible

last slate
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Literally I believe most of it is time waste

lavish venture
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they don’t know anything

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the college professors are better i’m sure

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but high school teachers

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yea not it

last slate
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It's been years of no breakthrough in physics lmao

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They discover new particles

keen hill
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there are breakthroughs every year just less fundamental than they used to be

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alot more specific and niche

last slate
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And shove up 100 papers on them claiming utterly stupid things

lavish venture
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but

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i wouldn’t say nothing

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but string theory

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can be

keen hill
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string theory is fake!!!!

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(It has not been talked about for decades)

lavish venture
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a bit of a waste of time

keen hill
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not seriously anyways

last slate
keen hill
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there are many formalities

last flint
keen hill
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but there is also much advancement in the field

last slate
lavish venture
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😳

keen hill
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quantum physics is definitely real

lavish venture
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what am i missing

keen hill
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string theory probably not

lavish venture
last slate
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How do you anything if it's real when you don't know about it

lavish venture
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do you mean by observation?

last slate
lavish venture
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you don’t think information can travel faster than light

last slate
last slate
keen hill
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Trusting human intuition is not great...

lavish venture
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isn’t that the premise of entanglement

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wasn’t there a nobel prize in entanglement like two years ago

last slate
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idk i will come back to answer that when I have finished studying qm

keen hill
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in 2022

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yes

last slate
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I am just very unsure of ideas

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In qm

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They don't make sense to me

lavish venture
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i thought it was the best theory there was

last slate
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I believe I need to know alot more

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To even start pondering around it

keen hill
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particles have been observed to behave as if they are "entangled" but I am with him on the fact that ideas that I am not too sure that I believe our current model is the accurate model

last slate
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I believe I should know lot of math may it be differential equations complex analysis or even real analysis

keen hill
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real analysis for physics 😳

lavish venture
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yea i didn’t read that griffiths book i’ve only read an algebra based textbook and watched youtube videos so i can’t say much

last slate
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Topology differential geometry

last slate
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they use theorems which have proofs in real analysis

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And physicists don't care about proofs mostly

keen hill
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yes

last slate
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But I personally do very much

keen hill
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the fundamental understanding of calculus is nice but it applies less handedly than other math

last slate
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idk

keen hill
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of course it wouldn't hurt but its extremely formal for physics

last slate
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i find it "necessary"

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to know it fundamentally

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maybe i am brainwashed by my mathematically profound seniors

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lol

keen hill
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math is beautiful

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I do plan to take it just because I like math

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though saying it's neccesary for physics is pretty farfetched

last slate
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i like it

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but yes

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like

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its not just about liking it for me

keen hill
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and you will have plenty of math to the point where you will teach yourself real analysis if you ever do need it by the end of your physics major

last slate
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i dont know what i will do if not study physics or math

keen hill
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I mean

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before real analysis it'll probably do more help to take pdes, complex analysis, numerical analysis, or even algebra

last slate
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and yes complex analysis but its necessary to do before i can do it later aswell

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like after real analysis

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it won't affect much ive been told

keen hill
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it shouldn't

last slate
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okay

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i will get started with integration

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i have a target to finish it by next month

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's end

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you both were a great chat , thanks for the information about america

lavish venture
#

mhm

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have a nice night

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damn it’s 430

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💀

last slate
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its morning for me

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lol

lavish venture
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i guess it’s morning for me too now

last slate
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i mean afternoon

lavish venture
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oh

last slate
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its 2 pm

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here

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i wake up at 10

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lol

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am

lavish venture
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guess i’ll wake up at 2 pm tomorrow

last slate
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goodluck

#

.close

midnight plankBOT
#
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midnight plankBOT
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primal patio
#

Can anyone hellpp??

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last slate
#

for the rectangular loop why is its differential surface element represented by the phi uni vector?

midnight plankBOT
#

Please don't occupy multiple help channels.

last slate
#

im very confused because this is what it gets represented by

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but like, this doesnt make sense? im confused

hard shard
#

i assume its probably the Bflux

last slate
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yeah but like

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how the frick is $\dd \vv s = \vc\varphi h\dd r$

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am i going crazy

grand pondBOT
hard shard
#

that looks like a gamma, but thats beside the point

last slate
#

yeah

hard shard
#

ngl idk what a_0 or a_phi is

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i feel like i should

last slate
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just unit vectors

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of the phi component in spherical/cylinderical coordinates

hard shard
#

ah

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they are taking vertical slices and finding the flux

last slate
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im looking around online and this person used the x unit vector instead?

hard shard
#

yeah, flux is perpendicular to the wire plane

last slate
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fair enough but like

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with phi the thing is yk

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uh

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in all directions

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i feel like im definitely missing out on something here

hard shard
#

your a_phi is tuned to be the one perpendicular to the wire plane i think

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(btw take everything im saying with a grain of salt, i just finished doing my first emag class)

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but yeah i think you pick phi hat to be perpendicular to the wire plane

last slate
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hmm

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why does this make sense actually

hard shard
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because i said it

last slate
#

love me some physics bullshit that feels inconsistent as fuck as with most things involving this stuff catThimc

hard shard
#

correction: you dont pick it, the phi hat is always perpendicular to the wire part (im trying to generalize to more complicated wires and its messing with my head)

last slate
#

how?

hard shard
#

i forget how direction pops out of a dot product integral

last slate
#

the phi unit vector changes direction at every point in space

hard shard
#

lets think about that later

last slate
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so how can it be simultaneously changing direction everywhere and still be always perpendicular

hard shard
#

ill sleep on it

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speaking of, im going to bed, hope i helped

last slate
#

lmao aight no worries

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sleep well

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still pretty confused though if anyone wants to chime in

hard shard
#

about what

hard shard
#

wait isnt flux B.dA

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integral of

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ointegral of*

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area vector is normal to the surface

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idk, good night

midnight plankBOT
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#

Please don't occupy multiple help channels.

zealous schooner
#

how many times will you guys post the same thing

#

lmaooo

#

I think all of you should create a group chat and discuss your paper over there, insteda of creating 6 different channels asking for just the answers of the same test...

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zealous schooner
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drowsy nova
midnight plankBOT
drowsy nova
#

I thought the answer was C as the dimension of the subspace is 6 (i think) and 6 =! 2 so its not isomorphic. Whys is c correct

(the real answer is e)

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tribal temple
#

Well, considering you can e.g. write 4 + sqrt{2} as a rational linear combination of 2 - sqrt{2} and 2 + sqrt{2}...

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tidal basalt
#

not sure if this is correct so far, but can anyone give me a hint on how to find the coordinates of D? thanks

tidal basalt
#

if the ab = dc thing is wrong pls lmk

primal granite
#

idk

tidal basalt
primal granite
#

миллионы умрут сука

tidal basalt
#

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undone mulch
#

1²+(1²+3²)+(1²+3²+5²)+.......sum of n terms of the series. help please

undone mulch
#

umm

#

hello?

#

@here

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misty marlin
#

Hello again . Sigh...this is not correct right? The question is: If 10 people do a job by working 5 days for 6 hours, how many hours a day should 15 people work to finish the job in 4 days?
Key: 5hours

midnight plankBOT
#

@misty marlin Has your question been resolved?

misty marlin
#

<@&286206848099549185>

heavy monolith
#

Use Unitary Method

misty marlin
heavy monolith
#

Sure

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Take 10 on one side

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Then take 5 days 6 Hours on other & convert days into hours

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5*24

misty marlin
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I think that is not right tho

heavy monolith
#

Wait let me try

misty marlin
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Because they work 5 days 6 hours not 24 hours

heavy monolith
#

But can't 5 Days be converted into Hours?

misty marlin
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Why would you

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It's not like they work 24/5

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Non stop

heavy monolith
#

Then is it given how many hours do they work?

misty marlin
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Yes. It's 6 hours

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A day

heavy monolith
#

Okay

#

Should have told earlier

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Anyways

#

Let me try

misty marlin
#

Alright

tiny drum
heavy monolith
#

Still, Thanks

#

Got it @misty marlin

misty marlin
#

What metod did you used

heavy monolith
#

10 Days times 5 Days times 6 Hours Daily = 300 Man Hours

misty marlin
#

Okay

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And then what

heavy monolith
#

Now, we need to find out how many hours a day 15 people should work to finish the job in 4 days:15 people * 4 days * x hours/day = 300 work hoursSolving for x:60x = 300x = 5 hours/daySo, 15 people should work 5 hours a day to finish the job in 4 days. Therefore, the correct key should be 5 hours.

misty marlin
#

Ooo okay

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Thank you diligentClerk

heavy monolith
#

&

misty marlin
#

?

heavy monolith
#

@misty marlin in which grade are you?

misty marlin
#

Uh...12

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Idk actually

heavy monolith
#

So you're in High School?

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& are you an American Citizen?

misty marlin
#

Yes

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No

heavy monolith
#

Which country?

misty marlin
#

Does it matter?

heavy monolith
#

It does

misty marlin
#

Why?

heavy monolith
#

Just tell me I am really curious

misty marlin
#

No

heavy monolith
#

Fine

misty marlin
#

That's not why this server exists

heavy monolith
#

In my country

misty marlin
#

but anyway thank you

heavy monolith
#

This is 4th grade Math

misty marlin
#

Ig

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Great 4u

heavy monolith
#

Anyways

#

Glad you got the answer

misty marlin
#

.close

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tiny drum
heavy monolith
#

Just asking the name of her county

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last slate
#

A water tank at a filtration plant is built in the shape of an inverted cone with height 5.2 m and diameter 5 m at the top. Water is being pumped into the tank at a rate of 1.2 m3 /min. Find the rate at which the water level is rising when there is 8π m3 of water.

last slate
#

is this asking for rate of the volume (because of the unit?) or do i solve for dh/dt

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#

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tribal temple
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#

@last slate Has your question been resolved?

last slate
#

i ended up getting 0.07m as an answer and idk if it’s correct

#

but i did work for dh/dt

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fresh ice
#

hi! My question is a little tricky, i want to re-learn maths from the beginning and i dont know how and where should i start from, Can anyone give me a guide or something? I appreciate it! thx!

lavish venture
#

what have you learned so far

fresh ice
#

i learned a lot of things in math but i did it just for the time, so the only things that i always remember are just addition, subtraction, multiplication and division

#

i'll probably get used to more of the topics because i may remember some of them, but i want to go step to step from the very beginning

lavish venture
#

so you don’t know any algebra

fresh ice
#

yep :(

lavish venture
#

maybe go to khan academy

#

they have everything from the very beginning

#

to early uni level math

fresh ice
#

they have it in order?

lavish venture
#

yup

fresh ice
#

like a path

lavish venture
#

by grade level

fresh ice
#

OH

#

that's seems to be the thing that i was searching for

#

thank you knief!

lavish venture
#

you’re welcome

fresh ice
#

how do i put the channel available again?

lavish venture
#

i’ll close it but in the future do what i write

#

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craggy ice
#

hi

midnight plankBOT
craggy ice
#

ignore the spanish text

#

shouldnt theta go from pi/4 to0?

#

topic: triple integral spherical coordinates

sharp coral
#

the y-axis is theta = pi/2

craggy ice
#

so thats wrong?

sharp coral
#

theta = 0 is always the positive x-axis

craggy ice
#

oh so like this?>

sharp coral
#

yes

craggy ice
#

ok bro ily

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last slate
#

When you convert a trig function into phasor form, is the frequency information lost?

last slate
#

I.e., [
A\6\cos{\omega t + \varphi} = A e^{j\varphi}
]

grand pondBOT
last slate
#

is omega just not recoverable after doing this?

surreal moon
last slate
#

how so

surreal moon
#

It needs to be $Ae^{j(\omega t+\varphi)}$

grand pondBOT
last slate
#

i dont think so?

#

unless im misunderstanding something of course

#

oh wait

#

this makes sense

hard shard
#

that table does not make sense

#

oh nvm

last slate
#

so that gets effectively ignorred in phasor domain?

#

heh

surreal moon
#

Oh yeah. So it does.

#

The $e^{j\omega t}$ is just discarded. It's up to you to remember to reinsert it when going back to time domain.

grand pondBOT
last slate
#

i see

#

makes much more sense

hard shard
#

it looks like the information is the domain

last slate
#

im new to this stuff so like

surreal moon
#

sometimes the phasor included the time component, sometimes it does not, at least from what I'm reading

hard shard
#

brb

last slate
#

btw just a curious question but what is this like

#

triangle notation they are using for the phi

#

what does it actually mean

#

,,<steinmetz>
z = 1.19 \phase{-78.2039\degrees}

grand pondBOT
last slate
#

i guess this is jsut phasor notation

#

ok thanks yall

#

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inland patio
#

In probability, when we want to obtain the marginal distribution of the joint distribution, there is this identity (in the discrete case) $$\left{X=x\right}=\bigcup _y\left{X=x{,}Y=y\right}.$$Suppose the union consists only of two sets, with points $y_1$ and $y_2$. Then, if we write ${X=x}$ as statement $p$ and ${Y=y_1}$ as $q$, we can write the RHS of the above equation as $$(p\land q)\lor (p\land \neg q),$$and this is equivalent with $p$, so it proves the set identity. How does one extend this to more points than two?

grand pondBOT
#

Philip

runic hamlet
#

show double inclusion

inland patio
# runic hamlet show double inclusion

ok, I guess a key assumption then is that $X,Y$ must have the same domain then (they are part of the same random vector), since if $\omega\in{X=x}$, then $X(\omega)=x$ holds, and likewise $Y(\omega)=y$ for some $y$ in the range of $Y$, so $\omega\in {X=x,Y=y}$ and thus it is in the union. Conversely, let $\omega\in\bigcup_y {X=x,Y=y}$, which means it is in some ${X=x,Y=y}$. How do we know from this that $\omega$ is in ${X=x}$?

grand pondBOT
#

Philip

runic hamlet
#

well X(omega)=x

inland patio
#

ok, I think I see {X=x} is a subset of {X=x,Y=y}, is that right?

runic hamlet
#

other way around

inland patio
#

ah yeah, ok, thanks 🙂

#

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midnight plankBOT
grand pondBOT
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Arch
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last slate
#

bruh,

#

😭

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inland patio
#

Let $(X,Y,Z)$ be a point chosen uniformly within the three-dimensional unit sphere. Determine the marginal distributions of $(X,Y)$ and $X$. \

I'm tempted to consider the joint density $f_{XYZ}(x,y,z)=\frac1{4\pi}$ when $x^2+y^2+z^2=1$ (as the surface area of the sphere is $4\pi$), however, this function will integrate to $0$ over the unit sphere. So this can't be the joint density. I'm a bit lost on how else I should proceed with the problem. Any ideas are appreciated.

grand pondBOT
#

Philip

rare pine
#

how did you do the integral?

inland patio
grand pondBOT
#

Philip

midnight plankBOT
#

@inland patio Has your question been resolved?

midnight plankBOT
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@inland patio Has your question been resolved?

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@inland patio Has your question been resolved?

inland patio
#

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finite jolt
#

I'm in calc 3 and we are going over surface integrals. One of the ways we do surface integrals is using the gradient for an implicit function, but I'm not sure how to know which is the independent variable?

finite jolt
#

$\frac{|\grad{g|}}{|g_z|}$

grand pondBOT
finite jolt
#

this thingy as the $d\sigma$ in the surface integral

grand pondBOT
finite jolt
#

but sometimes you use gz, sometimes gy, sometimes gx? idk whadda do lol

sharp coral
#

you generally integrate over a region of the surface projected onto one of the 3 unit planes (the xy plane in the image)

#

note that $g_z = \nabla g \cdot \hat k$, we are taking the dot product with the normal vector of the unit plane we are integrating over

grand pondBOT
sharp coral
#

so for example the xy plane has normal vector k, the yz plane has i, and the xz plane has j

#

which plane we choose is influenced by the shape: since we are taking its "shadow" on a unit plane, we can't have it "overshadow" itself

finite jolt
#

We set it up by doing a parametrization and taking cross products—is gz the dot product of the gradient and normal vector because k = <0, 0, 1>?

sharp coral
#

yes

finite jolt
#

Integrate the function $f(x, y, z) = z$ over the cylinder $y^2+z^2=4$ for $z\ge 0$ and $1\leq x \leq 4$

grand pondBOT
finite jolt
#

for this, the shadow would be the yz plane right?

#

But when you take the gradient of the function for the cylinder, the x component of the gradient is 0

#

So in class, we just used z, but how can you use z if the shadow of the cylinder is in the yz plane?

#

The TA said either x or z would work but not y, and I was confused why

sharp coral
#

the surface should lie above the plane it's being projected onto, and not cross it, and the surface crosses the xz plane (whose normal is j)

finite jolt
#

doesn't it cross all the planes?

sharp coral
#

not with the restrictions in place

finite jolt
#

Then wouldn't x not work either bc it crosses the zy plane as well?

sharp coral
#

we only care about the surface with the restrictions z ≥ 0 and 1 ≤ x ≤ 4, and with those restrictions it doesn't cross the other unit planes

finite jolt
#

hmm okay i'll see if i can apply this to the homework

#

thank you!

#

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last slate
midnight plankBOT
last slate
#

Anyway to go about this guys ?

#

How do I evaluate the last integral expression

marsh galleon
#

What's the original question?

last slate
#

Can you tell me

#

How do we integrate this

#

Rather than the original que

#

I wanna do it my way

marsh galleon
#

I'm asking because I see a strange substitution in line 1

#

What's the original question?

last slate
#

A strange substitution

#

Sqrt(tantheta)

#

Is original question

marsh galleon
#

How did you get from the integral of sqrt(tan(theta)) to the first expression on your page?

last slate
#

write tantheta in complex polar form

#

Divide numerator inside sqrt by e^itheta

#

Then put e^-2itheta = cosphi

#

So you can then write the whole term inside the sqrt as tan(phi/2)

#

And as a result of substitution we get a tan(phi) outside aswell

#

@marsh galleon

marsh galleon
last slate
#

Tantheta = (e^itheta - e^-itheta)/(e^itheta + e^-itheta)(i)

#

<@&286206848099549185>

marsh galleon
#

What's this exp(-2i theta) = cos(phi) stuff?

#

You've literally just written random scribbles and are leaving everyone else to figure it out...

#

What is phi? Where did it come from?

last slate
#

It's some arbitrary variable I've chose to substitute

marsh galleon
#

You're more likely to receive good assistance if you write out your attempt properly

last slate
#

don't help if you don't get it someone else will

#

I sent what I wrote

#

That's how i write

#

Not my problem if you don't get it

#

also why do you even need the previous stuff i asked how to integrate the last expression lol

wary trail
#
  • Asking a question:
  • Write out the original question
  • Write out your attempt
  • State what you need help on

And make it legible or noone will want to help you.

last slate
wary trail
#

absolutely not.

last slate
#

What's not clear

wary trail
#

What is what

last slate
#

Wait I'll write it on a paper

wary trail
#

I just need you to label what you have and what you want

last slate
#

I wrote the simplified version of what i want

wary trail
#

this is the question?

last slate
#

yes

wary trail
#

great

last slate
#

for me

wary trail
#

now show me your attempt

last slate
#

Tried creating a perfect square in the denominator

wary trail
#

and then what specifically you are wanting

last slate
#

Didn't seem to work

wary trail
last slate
wary trail
last slate
#

no the exponentials are all before this

#

that has nothing to do with this

#

i am asking you how to integrate this

#

they were curious about how i got here but ia m not

#

so i dont care

#

you may tell me how do i proceed from here

#

and thats the only thing i asked in the first place

#

they got onto me for something i didn't even ask

wary trail
#

who are you...?

last slate
#

i person asking for help in something "particular"

last slate
#

nvm

#

yeah

#

sorry

#

help

#

that was other acc

wary trail
#

that was you

#

cool

last slate
#

right

wary trail
#

let me write it out

last slate
#

Okay thanks

last slate
#

so it can simplify to solving for integral 1/1-(tanx)^2 now

#

but i am not sure how

wary trail
#

okay

#

just done it and can confirm u=tan(x) works as a substitution

last slate
#

lemme try

#

thanks

#

it works

#

.close

#

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last nebula
midnight plankBOT
last nebula
#

Can someone double check this?

#

especially the second one

#

not rlly sure if I did it right

midnight plankBOT
#

@last nebula Has your question been resolved?

last nebula
#

<@&286206848099549185>

steady trail
#

Hi

#

What is the problem ?

#

Do you have to find that all y's are the same?

cold wind
#

shouldn't circle be 31 in 1st

steady trail
last nebula
#

like idk how to explain

last nebula
steady trail
#

The last of the b seems wrong

#

Even the penultimate one

#

For the rest the others in b are correct

#

then the last one of the a is wrong

#

because it comes out -5

#

Not +5

last nebula
last nebula
steady trail
last nebula
steady trail
#

for example in the last of the b, subtract other additional symbols in addition to the star

last nebula
#

yea

#

does symbols mean numbers?

#

i don’t rlly get what u mean by symbols

steady trail
#

for example at the last of b Subtract the star 2 times and once the circle

#

So

#

$4(x+3)^2-24-24-3=4x^2+24x-15$

grand pondBOT
#

BobTheBuilder

midnight plankBOT
#

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#

@rare wharf Has your question been resolved?

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steep mirage
midnight plankBOT
steep mirage
#

did i do this correctly?

tiny drum
#

no, you have to divide everything by -5

steep mirage
tiny drum
#

(-4/5)x + 4 = y, yes

steep mirage
#

right*

tiny drum
#

rewrite what with y first?

still nacelle
#

where y is on the left hand side?

steep mirage
#

yes

#

is it fine to leave it or do i need to put it as that

still nacelle
#

it should be fine

tiny drum
#

it's the same thing, just convention

steep mirage
#

for this one slope would be 1/5 right>

tiny drum
#

yeah

midnight plankBOT
#

@steep mirage Has your question been resolved?

steep mirage
#

.close

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open sedge
#

I don't understand how they found the answers

midnight plankBOT
open sedge
#

thx!

#

could you help me with another problem?

#

also do u have tricks for these types of problems cuz idk when to use permutation or combination

small jasper
small jasper
open sedge
#

for this idk how to approach it 😭

small jasper
#

Let’s start with part (a)

#

Let’s say we have n distinct objects

#

How many ways are there to arrange them in a row?

open sedge
#

8!?

#

n!

small jasper
small jasper
#

For part (b), the couples have to sit together

open sedge
#

ok nice

small jasper
#

So we’re going to want to rethink what we’re ordering

#

What are we ordering in this case?

open sedge
#

uh the couples?

#

would it be 4! * 2!?

small jasper
open sedge
#

because theres 4! ways to arrange the couples

#

and * 2 if the man or woman switches

small jasper
#

Note you need to do it for each couple

open sedge
#

would it be 4! 2^4?

#

ok ty how about c)?

small jasper
#

Hint: consider how to order the men and then how you can place them in the line

open sedge
#

would it be 4! to order the men and then 4! to arrange the women?

#

it doesnt make sense in my head tho idk what im saying

small jasper
#

Now you need to figure out how many ways there are to put the men amongst the women

open sedge
#

idk how to figure that part out :/

#

why cant it just be 4! * 4!?

small jasper
open sedge
#

5?

#

so 4! * 4! * 5?

#

@small jasper how do you do them so easily?

#

like do u draw the situation or do u just know

#

or do you have a trick to know? 😭

#

also up till now are they all permutations and no combinations yet?

small jasper
#

If you can’t do this in < 30 sec then you’re dead

open sedge
#

wtf

#

😭

civic bough
#

There is a secret trick

open sedge
#

what is it pls

civic bough
#

Keep doing lots of questions and understand how to do them

open sedge
#

.

civic bough
open sedge
civic bough
#

Mr pigeon

small jasper
#

oh just

#

Alternate the strings of men and women

#

Basically what you did in (c) but easier

open sedge
#

would it be 4! * 4! * 2?

small jasper
small jasper
open sedge
# small jasper Yeah

so the reasoning would be theres 4! ways to order both men and women and we multiply by two cuz it can either be a man or a woman that starts first?

open sedge
small jasper
#

high school

open sedge
#

cuz im gonna take stats again in uni and i dont wanna do this

#

WHAT

#

aint nobody in highschool doing that?? 😭

small jasper
#

that’s the easy stuff

#

But on a more srs note

#

Combi is weird

small jasper
#

But it’s especially true for combi

open sedge
#

wait what i just did is combi?

small jasper
#

You need to acclimate yourself with the common setups

#

Because what happens is when you do harder combi

#

You’re often looking back on those common setups

#

And seeing how you can relate things to those

#

Sometimes you even reframe the question in terms of those common setups

#

Also there’s this things called “combinatorial arguments”

#

Which is using combinatorics to show something is true

#

More specifically, creating a situation that you can use combinatorics on to show something is true

#

The classic example is showing that $$\sum^{n}_{k=0} \binom{n}{k}=2^n$$

grand pondBOT
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Civil Service Pigeon

small jasper
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Ok maybe not the classic example but it’s pretty famous and standard

small jasper
open sedge
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i wouldnt be able to do that

small jasper
open sedge
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isnt combinations like

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5C4

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liek the C

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but the problems didnt need the C

small jasper
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The combinations formula is used in combinatorics

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But combinatorics as a whole is counting the number of ways to do stuff

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You don’t necessarily need the combinations formula

open sedge
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oh ok

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thx for the help

small jasper
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In fact, in the trivial cases, when you can technically use it, you don’t rlly need it

open sedge
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are u a math major

small jasper
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Eh idk

open sedge
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ur in highschool???

small jasper
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Pure math -> not a lot of money

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Being a teacher is meh

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And I tried research

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Don’t rlly like it

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So I’ll prob do data science/comp sci

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Smthn like that

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Maybe throw some AI in there

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I def need to get better at coding tho

open sedge
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wait what are u doing rn?

small jasper
open sedge
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WTF

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im in college rn 😭

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are u in the US educational system

small jasper
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Hence why I said being a teacher is meh

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It’s all going 📉

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Both student quality and admin support

open sedge
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and theyre teaching you these advanced stuff in AP stats

small jasper
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I don’t do AP stats ._.

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Also this is the very basics

open sedge
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then how did u learn all these stuff

small jasper
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We’re all tryhards

open sedge
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oh ok

small jasper
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Picked it up my first year of hs with no experience and just kinda

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Stayed with it

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Got some more influence on the scene as the years passed

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And now here I am

open sedge
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have u done calculus?

small jasper
small jasper
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I actually took the bc test today lol

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Pretty easy, there were a few questions I appreciated seeing

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But most of it was the same bland flavor as always

open sedge
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ok yall way too smart

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c'est assez

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anyways ty for the help

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.close

midnight plankBOT
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Channel closed

Closed by @open sedge

Use .reopen if this was a mistake.

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open sedge
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.close

midnight plankBOT
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Channel closed

Closed by @open sedge

Use .reopen if this was a mistake.

midnight plankBOT
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fast gust
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**is this attachted image correct judging by the following probability problem? **A letter is chosen from the word LEVEL without replacement and then a second letter is chosen from the same word.

midnight plankBOT
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@fast gust Has your question been resolved?

fast gust
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thanks!!

midnight plankBOT
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Channel closed

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Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

velvet wraith
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Yo

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Got answer key for this one too or what

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Yea that's correct as I see it

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Oh damn

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Yep

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Okay so we are given r = (1,4) and + s(0,2) now for this we need to eliminate s which is the parameter

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Our equation is a 2 dimensional space line where r is a position vector in our line (remember that 1,4 are only specific points in our line) and our (0,2) is the direction our vector takes in the line

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Ur getting it so far?

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Okay so how do u think the cartesian form of the line can be expressed as?

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We'll use good ol' y = mx + c

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Now next step would be finding our slope but since our vector is (0,2) and x is 0 and y is 2 which means that our line is vertical and parallel to the y-axis

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so yes with what I told u above m (slope) is undefined

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Okay since we know that our line is parallel to the y-axis what would that mean for x in (1,4)?

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Yep but to give more clearance since our line is parallel to y

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That means our x is constant

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Now to find the constant we used (1,4) because it's the coords that passes through our line

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Which is why x = 1 (constant)

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So in summary, the Cartesian form of the line is x = 1

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Yep! When the slope is undefined, it typically means the line is vertical, in this case, the line is parallel to the y-axis, so the only thing that changes as you move along the line is the y-coordinate, not the x-coordinate, so the x-value remains constant, which in this case is x = 1 as it passes through the point (1,4)

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Yep that's basically it

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12th Grade

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No lol

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Yea I just converted it we don't use grades in my country

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The year I'm in is equivalent to 12th grade apparently