#help-39

1 messages · Page 232 of 1

fringe robin
pearl pondBOT
fringe robin
#

Length of train is just length contraction (or dilation here)
How has distance been obtained, cant tell you where i dont understand because I cant start it

pearl pondBOT
#

@fringe robin Has your question been resolved?

regal herald
#

since the plane and the front of the train are approaching each other in the frame

(w+u)t represents how much the distance between them has decreased at time t [ or should i say it represents how far they have collectively travelled]

taking T to the time when the plane reaches the front

so (w+u)T represents the total length of the train (in the frame)

then the distance between them is the difference between the two

so (w+u)(T-t)

#

in short:

(w+u)t, distance travelled towards eachother at t
(w+u)T, total distance they will travel towards eachother before they meet

(w+u)(T-t), distance left between them at t

fringe robin
regal herald
#

yeah

fringe robin
#

and it looks like the next bit is just equating but my ipad ran out

pearl pondBOT
#

@fringe robin Has your question been resolved?

pearl pondBOT
#
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fossil warren
#

why do we have to add the value of the initial position? aren't you already technicially getting that by integrating from 0 to 3?

blissful cloak
#

the integraiton means the distrance travelled from 0 to 3

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but we need the strating value to "anchor" it

wild fable
fossil warren
blissful cloak
#

Imagine I told you I traveled 100 feet, and asked you "where did I end up?"

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that makes no sense unless I also tell you where I started

fossil warren
#

OHH rightt so you would need to add the position you're already at in order to answer that

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perfecttysm

#

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naive plume
pearl pondBOT
naive plume
#

i found the line of y2 but then

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i forgot what to do after that

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<@&286206848099549185>

fickle schooner
#

I would approach this with vectors

chrome plank
naive plume
naive plume
#

someone come back its due in 30 minutes 😭

quartz rampart
#

A line which touches a circle at exactly one point is a tangent to the circle

naive plume
#

how

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does that elp tho

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uh i cut the thing in half to make 2 right trianges is this helpful or useless

quartz rampart
#

wait is OA on the y axis and OC on the x axis

fickle schooner
# naive plume does that elp tho

Your circle is centered at (r, r) with radius r which can be defined by:
$(x - r)^2 + (y - r)^2 = r^2$

You can take one of your tangents $y = mx + c$ and substitute into that equation to eliminate either y or x.

Since it's a tangent, the resulting quadratic should only have one solution (indicating only one point of contact). For such a quadratic, the discriminant is 0

jolly parrotBOT
#

StrangeQuarkAL

fickle schooner
#

I think that's sufficient to find r

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I personally wouldn't do it that way cuz it's kinda tedious tbh

naive plume
#

in the next 26 minutes

fickle schooner
naive plume
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this is a similair problem that i had to do

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and my math guy wants me to do it ina similair way as to this

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probably

quartz rampart
#

i think we can prove AOC congruent to ABC

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ig it doesnt help tho

naive plume
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huh

naive plume
#

i was thinking like

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"how does math guy want me to do this"

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and last time there was pythagorean theorem and alla that stuff

quartz rampart
naive plume
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and like stuff about 1 2 and root 3

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like the lengths of a 30 60 90 right tirangle

quartz rampart
#

its a square

naive plume
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uh

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really..

quartz rampart
#

like do you know the property of tangent makes right angle with radius

quartz rampart
quartz rampart
#

ok nvm, if you did you could use it here and then distance bw centre and point would be sqrt(2)r by pythagorean theorem

naive plume
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oh kay

quartz rampart
#

hmmm, this seems tough without the property

naive plume
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aw shucks

fickle schooner
# naive plume

Fairly easy way:
You know both y1 and y2 and therefore you can find point A and C (they are y and x intercepts respectively). If you show that AC passes through the circle's origin (r, r), simply finding the intersection of y = x and AC would be sufficient to get a value for r.

naive plume
#

wha

fickle schooner
#

which part is confusing

naive plume
#

finding the intersection of y=x and ac

fickle schooner
#

Oh yeah, (r, r) lies on y = x and AC right?

naive plume
#

really

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how can u be sure

fickle schooner
#

for y = x: sub in the point (r, r) -> r = r which is true so it does lie on y = x

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AC is the one that needs some work

naive plume
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okay

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wait

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yk im finding the length of r?

fickle schooner
#

The two kites in the diagram are similar

fickle schooner
fickle schooner
naive plume
#

oh

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woah!

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OH I GET IT

fickle schooner
#

neat

naive plume
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wait

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i get the concept

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but

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i still dont get how to find it.. 😭

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im a tad slow at these things

fickle schooner
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what part are you unsure about?

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I can elaborate

naive plume
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how od i find the length

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of the isdes of the kite

fickle schooner
#

You can find them in terms of r by finding the intercepts
For example, the left side of the top kite - its length is (y-coordinate of A) - r

naive plume
#

okay

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wouldnt i need to find the length

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of AB

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then minur r

fickle schooner
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Yes, AO = AB

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just find A and C

naive plume
#

a= (0, 8sqrt3 -6)?

fickle schooner
naive plume
#

c= (0, 2sqrt3)?

fickle schooner
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no

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C is on the x-axis

naive plume
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i wrot ie wrogn

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(0,2sqrt3)

fickle schooner
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yeah

naive plume
#

okay

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then do i use

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distance formula

fickle schooner
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Nope

naive plume
naive plume
fickle schooner
fickle schooner
naive plume
#

y=4-root3x + 8root3-6?

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@fickle schooner sorry for ping but im runnning outta time 😭

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what do i do witht the equatoin of the line..

fickle schooner
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I said it earlier

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The intersection with y = x OR sub y = r, x = r

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since (r, r) lies on AC

naive plume
#

uhh..

fickle schooner
#

How do you find the intersection of two lines?

naive plume
#

set equations to eachoter?

fickle schooner
#

Yeah, you have AC and y = x

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y = 4 root 3x + ... equals to x

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We established that the solution should be r

naive plume
#

okay

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thanks

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HE SAYS I NEED PROOF

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that ac goes thru the middle

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of hte circle

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thisp pmo

pearl pondBOT
#

@naive plume Has your question been resolved?

pearl pondBOT
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empty vine
#

need help

pearl pondBOT
empty vine
#

I completed this chart and I wanted to double check to make sure everything is correct

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is this right?

wet osprey
#

Can you not ghost ping me

empty vine
#

please

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check over

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it is urgent

wet osprey
#

I’m not helping you even if I could

empty vine
#

please

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why not?

wet osprey
#

Don’t ghost ping people

empty vine
#

Im sorry

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But no one is helping

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and your role says very active

regal herald
#

why are you in such a hurry anyway

empty vine
#

so i assumed u are active

empty vine
#

and i need to hand it in

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but i want it to be correct

regal herald
#

If its not contributing to something i dont see why you would be bothered, its a learning process. And if it does contribute to something, then we cant help anyway

empty vine
#

?

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I dont understand

#

O

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No i want to double check tho

regal herald
#

did you just ghost ping again?

empty vine
#

?

regal herald
#

i saw it

empty vine
#

no i deleted because I mistyped

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I meant to ping my friend

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to help

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but hes offline

regal herald
#

right

empty vine
#

.close

pearl pondBOT
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turbid egret
#

not sure how to solve the following linear system:
$$xcos(t) + ysin(t) = 0$$
$$-xsin(t) + ycos(t) = tan(t)$$

jolly parrotBOT
turbid egret
#

textbook i'm using gives the answers

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$x = -tan(t)sin(t)$ and
$y = sin(t)$

jolly parrotBOT
turbid egret
#

but i'm having a real hard time figuring out how to get to that point

regal herald
#

from the first equation, x/y=-tan(t) if that helps you

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see what you can do with it

turbid egret
#

alrightt i'll see where that gets me

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thank u

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okay i'm still not getting very far at all with this

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i'm not very good with trig so this is really tough haha

regal herald
#

what did you try with it?

turbid egret
#

i tried multiplying both sides of the second equation by -x/y to see if that got me anywhere (it didn't) and tried setting the right hand side of the 2nd equation to -x/y to see if that helped (also didn't)

regal herald
#

alright ill give another push

use x=-ytan(t) in the second equation

turbid egret
#

i've tried that it gave me something like this $y(\frac{sin^2(t)}{cos(t)} + cos(t)) = tan(t)$

jolly parrotBOT
regal herald
#

what happens if you multiply by cos?

turbid egret
#

ohhhhhhhhhhhhhhhhhhhhhhhhhhhh

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ohhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

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i see now

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i don't know how i didn't spot that 😵‍💫

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thank you for the help

regal herald
#

no worries

pearl pondBOT
#

@turbid egret Has your question been resolved?

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slate kite
#

I don't understand quadratic equations (Sorry if the questions are in Spanish, I'm Mexican and I'd like some help)

slate kite
#

Help? Please

jovial kiln
#

lets try this one then

#

could you translate this particular question?

lone kite
jovial kiln
#

makes sense

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lets wait till the OP respawns

open rivet
#

Pi=3.1416 💀

quartz rampart
open rivet
quartz rampart
#

it kinda makes sense

jovial kiln
#

@slate kite u here?

midnight haven
#

R = 49 cm

open rivet
midnight haven
slate kite
#

okay, i don´t understand how can i solve it, i´m new in this

jovial kiln
# lone kite

lets try this one. is this accurate translation by the way?

pearl pondBOT
#

@slate kite Has your question been resolved?

slate kite
#

16- Calculate the time it takes for a body to fall from a height of 90 meters (take into account that gravity is equal to 9.8)

midnight haven
slate kite
midnight haven
#

Well you know the kinematics equations?

midnight haven
midnight haven
#

@slate kite stellar after which you can put it all in [2] formula to get time

midnight haven
#

@slate kite r u available?

slate kite
#

I'm solving it, I'm trying to see what mistakes I make when doing the quadratic equation

midnight haven
slate kite
#

I'm not very good at algebra, but I'm trying to get better every day, my goal is to become as great as you

midnight haven
#

@slate kite Well did you got the answer by yourself?

slate kite
midnight haven
slate kite
midnight haven
slate kite
midnight haven
slate kite
#

Okay!

#

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pearl pondBOT
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leaden osprey
#

Is this right

pearl pondBOT
sacred nova
leaden osprey
#

do i have to prove the unit circle thing

fair creek
leaden osprey
#

haha ty

fair creek
leaden osprey
#

where i wrote prove

sacred nova
leaden osprey
#

also

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did i mark everything right on the graph

sacred nova
#

like you’re asking if you have to prove the value of sine 11pi/6 ?

leaden osprey
#

yea like do i have to show something

fair creek
#

ah no, don't worry 😔

leaden osprey
#

ah okay

fair creek
#

it's like more personal preference from me but i firmly believe that it's not necessary to show it

sacred nova
#

I mean I’ve never heard of having to probe something like that, but has the teacher indicated that you should there?
it’s just something that’s easily plugged into the calculator
(if you have to prove it’d just be that sin 11pi/6 = sin (11pi/6 - 2pi) = sin(-pi/6) = 0.5 and a similar method for the other one

leaden osprey
#

ah okay yea i cant use the calculator for this haha

sacred nova
#

that makes sense

leaden osprey
#

also what about the marks on the graph

fair creek
#

handicapped i guess sully

sacred nova
#

sin (-11pi/6) = sin(-11pi/6 + 2pi) = sin(pi/6) = 0.5 **

leaden osprey
#

perfect ty

leaden osprey
sacred nova
#

they are

leaden osprey
#

.close

pearl pondBOT
#
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sacred nova
pearl pondBOT
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cosmic saffron
#

Assume x is 1 million (1,000,000)
and I only want 6 digits precision
that mean
p = 1
is enough?

cosmic saffron
#

my question is with
x = 1 million
are
p = 1
correct?

pearl pondBOT
#

@cosmic saffron Has your question been resolved?

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lone smelt
#

How to know if a non-factorisable quadratic equation (D<0) is always positive or negative for any value of x? I want to know this for an inequality question I sent. I want to cross multiply the quadratic but not sure if the sign will change

flat cedar
#

When D<0, check the coefficient of x^2 (let a) to check. If a>0 it's always positive and if a<0 it's always negative

calm wing
#

(if D<0, the quadratic does not touch the x-axis, so there cannot be a sign change)

lone smelt
#

alright, thanks a lot

#

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lucid moth
pearl pondBOT
lucid moth
#

I got an answer but its completely different

#

First the location of C we set g(x) = 0

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Which gives us x = +-2, so C is located at (2, 0)

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Then we integrate g(x) with limits 2 and 0

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G(x) = 2x - (x^3)/6
2[2] - ([2]^3)/6 - (2[0] - ([0]^3)/6)
4 - 8/6 = 8/3

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Then to get V we take 4 - 8/3 = 4/3

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Now for W we integrate f(x) between p and 2 and set it equal to 2(4/3)

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F(x) = -8/x
-8/[p] - (-8/[2]) = 8/3
-8/p = -4/3
8 = 4p/3
p = 24/4
p = 6

#

Which is not what they got...

#

Which step did I do wrong?

lucid moth
#

8/x^2

light helm
#

you differentiated instead of integrating

lucid moth
#

Oh 😭

#

Ok I fixed it and got the right answer

#

Thank you!

#

❤️

#

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heavy hill
#

can someone check my working for this

pearl pondBOT
heavy hill
merry carbon
#

,rccw

jolly parrotBOT
heavy hill
#

chartbit!!!! ❤️

merry carbon
jovial kiln
heavy hill
merry carbon
#

In order of ascending or descending powers of c?

merry carbon
merry carbon
#

It happens sometimes Hehe

#

It does give you a “nicer” number, at least, which seems what the question writer might have intended catGiggle

heavy hill
merry carbon
# heavy hill i think its descending

That’s fairs, there doesn’t seem to be a “universal” way to order these (the questions I’ve seen always tell you which way they do it!)

heavy hill
#

also really nice seeing you again!!

proper cradle
#

This is really weird

merry carbon
compact ridge
pearl pondBOT
#

@heavy hill Has your question been resolved?

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molten ridge
#

are the lengths of the tetrahedron equal to half of the circumference of the cylinder?

toxic lichen
#

yes

pearl pondBOT
#

@molten ridge Has your question been resolved?

molten ridge
toxic lichen
#

does not seem so...

molten ridge
#

what did u get?

#

after unfolding the cylinder, this is what it should look like

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cant i use pythag to find the length of the height?

long yarrow
#

if I am not mistaken a tetrahedron have equal side lengths right?

pearl pondBOT
#

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hearty thicket
#

can someone show me how to do this one?

hearty thicket
#

i know x^3e^x = x^3*sum{0}{infinity} x^k/k!

#

but im not sure how to get teh terms for the power series

frozen lantern
#

uh

#

do yk how taylor series work?

hearty thicket
#

yeah

#

is there a faster method than just to find all t he derivatievs of f and find a pattern

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for the coeffecient

frozen lantern
#

i mean this has e^x so it couldnt be that bad

chrome plank
hearty thicket
#

i see

#

ok i will just keep on finding the derivative then

pearl pondBOT
#

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frosty grail
#

Can someone tell me where I went wrong? I first found the derivative. From the third line, I used a trig identity for what’s inside the bracket

frosty grail
#

This question is on finding trig derivatives

rancid depot
#

how did you get from line 3 (the one with parens) to line 4

proper cradle
#

2cos^2x-sin^2x is not cos2x

toxic lichen
#

2cos^2(x) - sin^2(x) is not equal to 2(cos^2(x)-sin^2(x))

frosty grail
#

Oh

rancid depot
#

ohh i see

frosty grail
#

So it’s only if it’s common to both sin and cos

#

Oopsie

proper cradle
frosty grail
#

So I shouldn’t have used an identity..

proper cradle
frosty grail
proper cradle
#

It's correct

#

And thats the answer

#

If you want all of them in jus sin

frosty grail
proper cradle
#

Just write cos^2x as 1- sin^2x

frosty grail
proper cradle
#

mhm

frosty grail
#

Hello again
I don’t get how to do B

plush bramble
#

are you given any equations for position of a pendulum

frosty grail
#

Yes

plush bramble
#

or did you learn any

#

did you try using them

frosty grail
#

It’s defined as h(t) = Acos(2(pi)(t)/T)

#

So I worked around with it

#

I found T to be 1.42 s

#

I said the amplitude is 8, but I’m not sure about that

#

Because it’s the maximum horizontal displacement

#

And I imagined that’s how high or low the sine graph would get

#

Is that correct?

pearl pondBOT
#

@frosty grail Has your question been resolved?

#
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runic zephyr
#

Question:
find all points where f(x, y) is continuous.

Hello !
i have no clue how to calculate the limit.

cobalt hinge
#

!occupied

pearl pondBOT
#

Someone else is already using this help channel. If you need help with a question, please open your own help channel/thread (see #❓how-to-get-help for instructions).

cobalt hinge
#

Lelel it’s fine

rose basin
#

relax we posted at the same time

runic zephyr
runic zephyr
#

but is it even x -> y ?
like isnt it supposed to be (x, y) -> (a, a) ?

cobalt hinge
#

Yeah.

#

Just simplified convention.

runic zephyr
#

oh

cobalt hinge
#

Sorry, I don’t really write too formally mathematical wise.

runic zephyr
#

because this is the solution but it doesnt make any sense to me

runic zephyr
cobalt hinge
#

Recall the limit definition of the derivative.

runic zephyr
cobalt hinge
#

That’s for 3D.

runic zephyr
#

i meant 2d world for x, y

#

excluded f(x, y)

cobalt hinge
#

Hmm.

runic zephyr
lime anvil
jolly parrotBOT
#

Yusername

cobalt hinge
#

Maybe treat one of them like a constant.

rough stream
#

y is the only variable in the limit. x is a constant.

#

lim (x,y) -> (0,0)
Is like the "path limit"

#

Which I would tex if I knew how

runic zephyr
#

when you consider y = constant and x = variable you are only tracing one possible curve out of inifinite more

rough stream
#

y is the only variable in the limit. x is a constant

#

At least judging by the notation used above

runic zephyr
#

but im saying that its not correct

#

because you are saying x = a and you change the variable y

#

you cant deduce that the limit exists because you got to an answer from one possible path

pearl pondBOT
#

@runic zephyr Has your question been resolved?

runic zephyr
#

.close

pearl pondBOT
#
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pearl pondBOT
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hoary musk
#

Hello i need help with this math problemMake a calculation based on the data obtained:

You own a restaurant and regularly procure the resources necessary to keep the restaurant running.

Specifically, you procured 200 eggs at 2000 dinars, 60 litres of oil at 9000 dinars and 10 kilos of salt at 1200 dinars. The dependent cost of these goods is 100 dinars, the gross salary 300 dinars, the margin is 2% (16 dinars) and the VAT is 24,48 dinars.

Calculate the price you'll be selling an omelet at your restaurant.

hoary musk
#

😔

rain vessel
#

What is a VAT?

#

!original

pearl pondBOT
#

Please show the original problem, exactly as it was stated to you, with the entire original context. A picture or screenshot is best. If the original problem is not in English, then post it anyway! The additional context might still be helpful. Do your best to provide a translation.

hoary musk
#

It translated bad my bad

rain vessel
#

No worries

#

VAT is general consumption tax?

hoary musk
#

Nah

#

It was translated bad

woven matrix
#

VAT is value-added tax, which is sort of the sales tax of the US

hoary musk
#

Ohh i tpught it was something bad translated

#

Then its VAT

hoary musk
#

We go to online classes and teach sent it in google classroom and idk how to solve it

rain vessel
#

I feel like some information needed is missing

#

Like for example, what are the ingredients needed to make an omelette

hoary musk
#

Egg oil salt

rain vessel
#

Also what do “gross salary” and “margin” mean in this context

rain vessel
hoary musk
#

Thats gross salary

rain vessel
#

And margin?

hoary musk
#

1 sec

rain vessel
hoary musk
#

the amount by which one thing is different from another:

#

Thats margin

rain vessel
#

What is it in this specific context

hoary musk
#

I do not know it only says that in text

#

That the teach sent

rain vessel
#

I’ll assume it’s saying profit margin, and each omelet must make 2% profit

#

Which is 16 dinar

hoary musk
#

Yes

rain vessel
hoary musk
#

Oh wait nvm

#

Someone set me the answer

#

Sent me*

#

One of my friends did it

#

Sorry for maybe wasting time

rain vessel
#

Please close the channel if you are done

hoary musk
#

How

#

!close

rain vessel
#

Type .close

hoary musk
#

.close

pearl pondBOT
#
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fallen flare
#

About the implicit function theorem. If the theorem applies, then the equation F(x)=0 has a solution set of (g(y),y) where g(y) expresses the basic variables (lets call them x) in terms of the free variables (lets call them y), but only in a neighborhood of a point c st F(c)=0. It's this last part that I don't get, why would the implicit function exist only for a neighborhood of such a point? What does this mean in practice? Mind you, I've gone over the proof of the theorem so I'm aware of the logical argument, I'm just unable to visualize what this means in application.

My book provides the following example with the unit circumference, could you help me understand from it please?

pearl pondBOT
#

@fallen flare Has your question been resolved?

last moth
pearl pondBOT
#

@fallen flare Has your question been resolved?

fallen flare
#

oh well, I see that any x is valid for F(x,y)= x^2+y^2-1, but only in the domain where x is in the aforementioned range can we describe y in terms of it

#

thanks

#

.close

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#
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merry carbon
#

Interesting that those who want everyone always forget the <@&268886789983436800> sadCatThumbsUp

pearl pondBOT
#
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shrewd mist
#

Vibrations & Control Systems (yeah ik its physics but I have enough helping equity to ask this lmao)
Consider the first image (two blocks, two viscous dampers, two springs)

An impulse I is applied downwards on m2. The goal of my project (partially) is to minimize the maximum displacement of the lower mass, m1 by setting the values of the two viscous (linear) dampers, c1, c2. I'm also trying to perform modal analysis (ie. what damping coefficients make it over, underdamped, etc- but that's secondary)

My EoMs in matrix form are also attached (2nd image). The coordinate system is + downwards, hence a +ve forcing term. At this point I chucked these EoMs into MATLAB to solve the ODEs numerically and iterated through c1 and c2 values to get an optimal set of values for a defined set of k1,k2 m1,m2, and impulse. Fwiw, my m1 = 3.6, m2 = 8.9, k1 = 51500, k2 = 2150, I = 500. All units SI. The values aren't too important though.

With these parameters, and bounding c1, c2 between [0,200], I get an optimal value (value that minimizes the absolute displacement of x1) of c2 around 60, with no significant dependence on c1. However, if I bump c1 up by an order of magnitude to ~2000, the optimal value of c2 crawls up with it to ~120, and then increases somewhat proportionally to c1. Ie. with c1 at around 8000, c2 is optimized at 300.

For the damping analysis, I got the TF of the lower mass as such (images 3 and 4)

I'm kinda at a block at this point. This is a 4th order system, is there any way for me to determine if the system is underdamped or overdamped (ie. can we- either analytically or approximately get some damping ratio and check if its less than or more than 1)? More broadly, does the concept of underdamped and overdamped even apply to a system of order > 2?

The prof "hinted" at working/trying to get the poles, but I'm a bit lost as to what to do with them. For low values of c1,c2- my poles are all imaginary, for intermediate values, 2 real 2 imaginary.

(1/2)

shrewd mist
#

For high values of c1,c2- all real, but still negative. All I can draw from this is that it appears to be BIBO stable.

#

The primary problem I want to figure out at this point is how can I determine if the system is over or underdamped?

pearl pondBOT
#

@shrewd mist Has your question been resolved?

pearl pondBOT
#

@shrewd mist Has your question been resolved?

pearl pondBOT
#

@shrewd mist Has your question been resolved?

pearl pondBOT
#

@shrewd mist Has your question been resolved?

pearl pondBOT
#
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full cobalt
pearl pondBOT
full cobalt
#

I have 0 idea how to do dis

toxic lichen
full cobalt
#

Co means together ik

toxic lichen
#

in numerical terms, we say two angles are coterminal if their difference equals a whole number of full turns.

#

a full turn, of course, is 2pi radians.

#

does this ring a bell?

#

@full cobalt

full cobalt
#

Im jus learnin bout dis

#

So not rlly

toxic lichen
#

ok well i explained what it means for two angles to be coterminal.

#

so what you need now is to start from your angle of 19pi/6 and go down or up in steps of 2pi until you land between 0 and 2pi.

pearl pondBOT
#

@full cobalt Has your question been resolved?

pearl pondBOT
#
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full cobalt
#

@toxic lichen

pearl pondBOT
toxic lichen
#

like, where to do the working for it?

#

paper.

full cobalt
#

U said start my angle at 19pi

#

And go down or up

#

In steps of 2 pi

#

Until i land beyween 0 and 2pi

#

How i do that

#

@toxic lichen

toxic lichen
#

ok

#

well

#

let's think about it

#

right now you're looking at the angle 19pi/6.

#

are you above the range [0, 2pi], already in it, or below it?

full cobalt
toxic lichen
#

well yes but actually no

#

i would rather you think about the number line

#

and don't overthink it

#

@full cobalt you still here?

#

this question didn't really require more than at best a minute of thought imo

pearl pondBOT
#

@full cobalt Has your question been resolved?

pearl pondBOT
#
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pearl pondBOT
full cobalt
oak ivy
#

uh ann is saying to reduce 2pi?

#

19pi/6 - 2pi

#

since if we increase or decrease by 2pi we will be at the same point

oak ivy
full cobalt
oak ivy
#

subtract 2pi

toxic lichen
oak ivy
#

lol

full cobalt
#

I was doing another hw

#

Mb

toxic lichen
#

rghghr.

#

ok right

full cobalt
#

The hell is rgrhrgr

oak ivy
#

angry

full cobalt
#

💀

toxic lichen
#

nothing, just a keysmash

#

grumble grumble

#

that's all

full cobalt
#

So 19pi over 6

#

Minus 2pi

oak ivy
#

Yes

toxic lichen
#

yes

full cobalt
#

And that result

#

Is the angle ?

toxic lichen
#

work it out first

#

i would really appreciate if you tried to put some thinking into it, rather than just blindly following some directions you were given

oak ivy
#

Adding or subtracting 2pi will give us the same position on the circle

toxic lichen
#

cause if you encounter a different problem with a different number

#

i would NOT want you back at the "stuck idk what to do HELPPP" position

full cobalt
#

Fair

#

I got a decimal

#

3.665

oak ivy
#

huh

#

u get in terms of pi

full cobalt
#

I put it in my calc

oak ivy
#

dont

#

write it in terms of pi

full cobalt
#

Idk how

#

3.665 pi?

oak ivy
#

no

#

what is 19pi/6 - 2pi??

vapid cave
#

do it in pen and paper or ur mind

oak ivy
#

You don't need to use calculator

full cobalt
#

I don know how to do it without calc

oak ivy
#

Bruh just write it down

toxic lichen
#

do you know how to subtract $\frac{19}{6} - 2$ by hand?

jolly parrotBOT
oak ivy
#

And subtract

toxic lichen
#

like forget the pi for now

#

and try to recall if you know how to add/subtract fractions

full cobalt
toxic lichen
#

"add" is not a good word to be using.

#

but if you want to turn the 2 into 2/1, by all means, go for it.

oak ivy
#

LCM

full cobalt
#

So then it 17 over 5

oak ivy
#

huh

#

no

#

u can only add/subtract like fractions

full cobalt
#

19-2 17

oak ivy
#

meaning they should have same denominator

full cobalt
#

Ooo

toxic lichen
#

ok ok ok hold on yes

#

again

#

work it out on paper, not in the discord chat box NOR in your head

oak ivy
#

So convert that 2 so that it has the same denominator

toxic lichen
#

@full cobalt did you try to do it in your head there just now?

full cobalt
#

So 19 over 6 and 2 over 6

toxic lichen
#

on paper, then?

oak ivy
#

uh

full cobalt
#

Yes.

oak ivy
#

it's 2/1 right

toxic lichen
#

also be mindful of the fact that 2/1 is not the same as 2/6

oak ivy
#

so how can u write that as 2/6

toxic lichen
#

so you really need to go over adding and subtraction fractions, converting to common denominator, all that stuff again

#

lemme get you a video...

oak ivy
#

how can u convert that 1 into a 6 @full cobalt ?

toxic lichen
#

This math video tutorial provides a basic introduction into fractions. It explains how to add, subtract, multiply and divide fractions. It contains plenty of examples and practice problems including examples of adding and subtracting three fractions instead of just adding and subtracting two fractions.

Fractions - Basic Introduction: ...

▶ Play video
full cobalt
#

U said they shoulf havr same denominator

oak ivy
#

yes

#

so you multiply 1 with 6 to get it to 6

oak ivy
#

but you also need to multiply the numerator with the same number

full cobalt
oak ivy
#

Whatever you multiply to denominator multiply the numerator with same number.

oak ivy
#

yes

full cobalt
#

So 12 over 6

oak ivy
#

yes

full cobalt
#

19 over 6 minus 12 over 6

#

7 over 0

oak ivy
#

No

#

You only subtract numerator

#

Denominator stays the same

#

You only perform addition/subtraction on numerator

full cobalt
#

O alr

#

So 7 over 6

oak ivy
#

yes

#

now that's 7pi/6

full cobalt
#

And 7 divides into 6 3 times

#

So 3 over 1

oak ivy
#

huh no

full cobalt
#

Shi mb

oak ivy
#

That is the simplified

#

7pi/6

full cobalt
#

So das the answer 7pi over 6

#

Where did the minus 2 come from again

oak ivy
#

..

#

cause

#

if we add or subtract 2pi

#

We land up in the same point

full cobalt
vapid cave
#

yea

full cobalt
vapid cave
#

we just add or subtract 2pi until the angle is within the given range

full cobalt
#

So any question in that format

#

I jus add or sub 2pi

#

As a fraction

#

Finding a common denominator

vapid cave
#

and repeat until it’s in the range

oak ivy
#

So basically

#

What is 19pi/6

full cobalt
#

How do ik when its in range

oak ivy
#

Use calculator

#

What is 19/6

vapid cave
#

when it’s between the bounds

#

in this case between 0 to 2pi

oak ivy
#

I don't think they understand that

#

@full cobalt what is 19/6

full cobalt
#

A fractiln

vapid cave
#

in cases like this where everything is by pi just divide to make things easier for urself

full cobalt
#

3.167

oak ivy
#

Ok

#

Is that within 0 to 2

full cobalt
#

Its highet

oak ivy
#

Yes

#

So then subtract 2pi

#

so 19pi/6 - 2pi

full cobalt
#

Ohhhhh

#

Ok what if

#

Without the -pi

#

I do it like it is in calc

oak ivy
#

SO basically

full cobalt
#

And it happens to be between 0 and 2

oak ivy
#

u got 3.167

#

You write it as 3.167 pi

full cobalt
#

No i mean for a diff question

oak ivy
#

And that is higher than 2pi

full cobalt
#

Example

#

Wjhat if it happens to be within 0 and 2

#

Can thst happen?

oak ivy
#

Then don't do anything

#

It's already solved

full cobalt
#

And if ot dosnt

#

Then i add or sub 2pi

oak ivy
#

THen probably they will ask to find the angle >2pi

full cobalt
#

To make it within 0 and 2

oak ivy
#

Yes

#

0 and 2 pi*

full cobalt
oak ivy
#

Add 2pi??

full cobalt
#

2pi +2pi?

oak ivy
#

If they give between 0 and 2pi and ask >2pi just add 2pi

#

Example they give u pi and ask to find a value >2pi similar to pi

#

Could you tell me what it is

full cobalt
#

2pi?

oak ivy
#

uhn o

full cobalt
#

Pi +2pi?

oak ivy
#

yes

full cobalt
#

Das how to get the angle of pi?

oak ivy
#

To make it better suited

#

Yes that's it

#

Just divide fractions if u wanna see where it lies and put a pi

#

19pi/6

#

can be 3.167pi

#

which is >2pi

full cobalt
#

Alr i got it now

#

Thx mask

oak ivy
#

ok

pearl pondBOT
#

If you are done with this channel, please mark your problem as solved by typing .close

#

@full cobalt Has your question been resolved?

#
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vernal hinge
#

can someone help ques 84 i feel imposible to integral like normal

vernal hinge
#

do i have to change something

pearl pondBOT
#

@vernal hinge Has your question been resolved?

vernal hinge
#

<@&286206848099549185>

leaden cape
pearl pondBOT
#

@vernal hinge Has your question been resolved?

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sharp smelt
#

Trying to parametrize this surface

pearl pondBOT
sharp smelt
#

I was thinking I'd once more start off with a parametrisation of the sphere and move from there

#

so I have $(3 \cos(\theta)\sin(\phi), 3 \cos(\theta\sin(\phi), 3 \sin(\phi)); 0≤\theta≤\pi ; 0≤ \phi≤ π/6$

jolly parrotBOT
#

What a wonderful world !

sharp smelt
#

seems to work

#

.close

pearl pondBOT
#
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sharp smelt
pearl pondBOT
sharp smelt
#

I'm supposing hyperbolic identities would be required here

#

.close

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feral trellis
#

How come this NFA rejects 10? What stops you from going q1->q4?

toxic lichen
#

do you even GET to q1 in the first place

#

i do not see an arrow leading out of q0 that says 1

stone warren
feral trellis
stone warren
#

you can reach q4

#

you cannot terminate at q4

#

you still have a 0 edge to take

#

and no edges in NFA means it goes to a sink

#

which is not going to be terminal state

feral trellis
#

That makes perfect sense thank you very much!

#

.close

pearl pondBOT
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pearl pondBOT
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rough forge
#

hi can someone rate my proof?

pearl pondBOT
jolly parrotBOT
robust oar
#

10/10

merry carbon
#

A SCsnuggle/10

rough forge
#

ok it seems to be okaish

#

thank yall catRoll

#

.solved

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celest heart
pearl pondBOT
open rivet
celest heart
#

definition of a lineair function:

f(u+v) = f(u) + f(v)
f(cu) = cf(u)

but dont really know what to do tbh

open rivet
#

plug it into the definition 🤠

#

you are probably thinking too much

toxic lichen
celest heart
#

so af(u+v) = a[ f(u) + f(v)] = af(u) + af(v) ?

celest heart
toxic lichen
#

otherwise you have zero hope of proving anything about an object which you don't even know what it is

celest heart
#

wait so maybe

#

alpha f just maps from 1 vector space to another?

toxic lichen
#

mmm incredibly vague.

celest heart
#

shit

#

Idk then ;/

toxic lichen
#

ok right

#

$\alpha f : V \to W$ is the function which maps each $v\in V$ to $\alpha \cdot f(v)$

jolly parrotBOT
toxic lichen
#

ie $(\alpha f)(v) = \alpha f(v)$

jolly parrotBOT
celest heart
#

Hmmm okay

toxic lichen
#

write out, carefully and without trying to overthink it,

#

what it would mean for alpha f to be a linear map

#

it is not hard and it does not require any heavy lifting at all

celest heart
#

so i start with (af)(u+v) and want to end up with af(u) + af(v)?

toxic lichen
#

so perhaps you do

celest heart
#

Hmmm alright

shy spindle
celest heart
#

so this?

toxic lichen
#

in the first line i think you have a stray equals sign at the very end

celest heart
#

ah ye true that one should not be there

toxic lichen
#

also your opening bracket looks too much like a c. yes, sorry, i am bashing your handwriting again.

#

other than that you seem good to go

celest heart
#

Hahahah any tips ;-;

#

for the handwriting again

#

I changed my 4!

open rivet
#

go slower 🙂

celest heart
#

but fr

#

c and ( or lowkey just the same

toxic lichen
#

no

celest heart
#

ill make the brackets bigger

toxic lichen
#

c is an arc of a smaller radius and greater angular measure

celest heart
#

yes!

#

Ill take notes of this too

#

Thank you guys :) really appreciate it

#

Wait ill close this in a sec i am trying a question that is almost the same

shy spindle
celest heart
#

Proof f+g is a lineair function

#

this correct?

toxic lichen
#

seems so

celest heart
#

Lets goooo

#

Thanks ann :) Have a wonderful day/night

#

.close

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pale frost
#

how can i find

pearl pondBOT
pale frost
#

$\sqrt{-57 - 16i}$ ?

jolly parrotBOT
#

jandro0103

#

jandro0103

pale frost
#

I would like to know how to calculate the square root of the discriminant

tropic saddle
#

comvert to polar form

#

alternatively, multiply out (a+bi)^2 and compare coefficients

pale frost
pearl pondBOT
#

@pale frost Has your question been resolved?

pearl pondBOT
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@pale frost Has your question been resolved?

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pale frost
#

<@&268886789983436800>

pearl pondBOT
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uneven radish
#

i dont think i understand any of this

pearl pondBOT
pearl pondBOT
#

@uneven radish Has your question been resolved?

jovial kiln
#

you have to add the torque by gravity and torque by F then express it in the form of
I d^2θ/dt^2 = t_F + T_g
using newton's second law (I being moment of inertia)

#

then the simplifcation follows by subbing in values given

#

for second part, let -4.9sin(theta) = -4.9theta and 0.03125cos(theta) = 0.03125

#

you get θ'' + 4.9θ = 0.03125
which you can solve using characteristic equation of the homogeneous equation and finding the particular solution

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pearl pondBOT
mental imp
#

I get how to do this question, but im confused about how come we can start it at the origin and everything still works out?

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mental imp
jovial kiln
#

.reopen

#

i think u might need to reopen channel

mental imp
#

uh oh

#

ok will do

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clear orchid
#

Doing homework probability questions
Not sure how to show that the recursion goes to what i have for part d
How do i get from part c to d

pearl pondBOT
#

@clear orchid Has your question been resolved?

clear orchid
#

<@&286206848099549185>

pearl pondBOT
#

@clear orchid Has your question been resolved?

clear orchid
#

i just need direction for a show that question going from my final answer in part c to part d

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brisk pike
#

hi

pearl pondBOT
brisk pike
#

so yesterday i came here asking everybodys help to find a fallacy in the following argument:
Say you threw a body up (no air resistence). At the maximum height it can achieve, we know for a fact that its instantaneous velocity $v$ will be 0, and acceleration will be $a= -g$.
But we know of a formula, $a = v \frac{dv}{ds}$ where putting $v=0$ would imply that $a=0$

jolly parrotBOT
#

rak³en

brisk pike
#

I still dont get the problem, so I am taking someones advice and will work through an example

#

lets say we threw it up with an initial veloctiy $u$, then $v(t) = u-gt$.

jolly parrotBOT
#

rak³en

brisk pike
#

We can solve for $t$ from the second equation $s=ut - 5t^2$ (assume $g$ is $10$)

jolly parrotBOT
#

rak³en

brisk pike
brisk pike
# jolly parrot **rak³en**

anyhow since we're going up we want to minimise $t$ so we choose $t=\frac{u - \sqrt{u^2 - 20s}}{10}$. Putting this in $v(t)$ we find $v(s)$ to be $$v(s) = u - g\frac{u - \sqrt{u^2 - 20s}}{10} = u - (u - \sqrt{u^2 - 20s}) = \sqrt{u^2 -20s}$$

iron basin
#

hm

#

im not sure either

#

ill try too

brisk pike
#

is this all correct?

#

anyhow differentiating the below once

jolly parrotBOT
#

rak³en

brisk pike
#

so we find $a(s) = - \frac{10}{\sqrt{u^2 - 20s}}$

jolly parrotBOT
#

rak³en

brisk pike
#

o

#

I see now

#

$v(s) = 0 \implies s = \frac{u^2}{20}$ but $a(s)$ is undefined for this

jolly parrotBOT
#

rak³en

brisk pike
iron basin
#

this basically

brisk pike
#

I can say 'dv/ds' must exist

#

but in the scenario v=0 but I cannot solve for v or s then I cant really know whether dv/ds exists, does it?

#

<@&286206848099549185> 👆 is the final question

iron basin
#

dv/ds doesn't exist

#

but dv and ds do

frozen lantern
#

what are you doing

iron basin
#

thats why the integral form of this works

brisk pike
#

huh?

brisk pike
iron basin
#

the third equation of motion

brisk pike
#

no idea what you're talking about

#

but

#

wait

#

yeah i cant turn the 3rd equation into an integral

frozen lantern
jolly parrotBOT
brisk pike
#

i dont see whats wrong if we dont know the nature of v(s)

frozen lantern
jolly parrotBOT
iron basin
#

we don't really use the differential form much anyways

brisk pike
#

but what if i dont (or its too complicated)

frozen lantern
brisk pike
iron basin
#

well

#

you could just integrate your way through it

frozen lantern
#

im not

brisk pike
#

I am asking IN SITUATIONS OTHER THAN FREE FALL

#

where i might not know what v(s) is

#

then how do i know that equation holds true or not

#

ofcourse if i know v(s) I can most probably just do what i did for free fall

iron basin
#

im not sure if you'll encounter such a situation

#

if you do you're welcome to discuss it here

frozen lantern
#

do you wish to overgeneralise $v\frac{dv}{ds}$ as being \textbf{definitely} 0 when $v=0$, despite $\frac{dv}{ds}$ not being defined for the \emph{one case} in which you can model it?

brisk pike
#

...............

iron basin
#

a dollar

jolly parrotBOT
brisk pike
#

nvm

#

i am troubling myself for no reason

#

thanks for beating some sense into me

#

.close

pearl pondBOT
#
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