#help-0

1 messages · Page 625 of 1

deep field
#

Maybe discord counted that as something I’m still typing

visual fjord
#

x^2 + 4y^2 = 40
xy = 6
how do I find the value of (x + 2y)^2 ?

rigid smelt
#

Can you expand (x+2y)^2 for me?

sullen nova
#

@visual fjord Expand

green urchin
elfin snow
#

e x p a n d

proud burrow
#

@visual fjord it's simple just expand (x+y) ^2 then you will get answer

sullen nova
#

@visual fjord Where are you at?

hybrid ridge
#

Pls anybody help me. What is {(2x+3x-9y)-7z}

#

I am so confused

eternal spindle
#

the notation {a} means the fractional part of a

alpine sable
#

Dream what is the whole problem

visual fjord
#

nevermind i got it
the answer is apparently 64 because there was a formula that i never knew existed

glass lichen
visual fjord
#

yes and substitution was involved

glass lichen
#

Oh no, not subbing in stuff

hybrid ridge
#

What the hell is this?

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I don't know this

eternal spindle
#

bruh

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nvm wait

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{a} = a - floor of a

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floor a means the greatest integer smaller than a

glass lichen
#

$a=\floor{a}+{a}, a\in\mathbb{R}^+$

ocean sealBOT
eternal spindle
#

ooh

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i was trying to type this'

#

but im bad at latex

eternal spindle
hybrid ridge
#

I mean I wanna plus plsu and minus it

alpine sable
#

Add 2x and 3x

eternal spindle
#

ya

hybrid ridge
#

{(2x+3x-9y)-7z}

alpine sable
#

You get 5x - 9y - 7z

eternal spindle
#

get he fractional part of it

#

i guess

hybrid ridge
#

Thanks

alpine sable
#

Yw

hybrid ridge
#

Thank God you helped. Or I will stuck with this question forever

silent raft
#

this some beta ass shit but can someone explain im in fucking 10th grade and i dont remember this shit from year 8 😭

manic quail
silent raft
#

yeah ofc

sweet mural
#

14*9

silent raft
#

i just forgot how to work it out

manic quail
#

multiplying the denominators (14*9) always gives you a "common" denominator

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It isn't necessarily the smallest though.

sweet mural
#

you need to find least common denominator in this case it's their multiplication

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so for the first one you will do 14*9 + 2 you can figure out for second one

silent raft
#

wait wdym by 14*9 + 2

sweet mural
#

you need to find upper value for first one to i showed you the way

glass lichen
#

you really need to work on your explanation if that's what you meant

#

"do 14*9+2" doesnt explain anything you meant

sweet mural
#

didn't wanted to write him the solution but basically he need to find least common denominator for those 2 given values

silent raft
#

bruh i just wanna know the fastest way to work it out cause my brain is dead

#

its like 4 am

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and i havent slept for ages

glass lichen
#

14 and 9 are coprime so 14*9 is the smallest denominator

silent raft
#

i

sweet mural
#

do you know how to calculate your numerator for the first one ?

glass lichen
#

$\frac{2}{14}=\frac{2}{14}\cdot\frac{9}{9}$

ocean sealBOT
lofty kelp
#

I keep on getting 64.74

lilac lantern
#

x=23.43356414207485

lofty kelp
#

can you tell me what I do incorrect?

#

@lilac lantern

lilac lantern
#

yes

lofty kelp
#

is it not tan opp/adj ?

lilac lantern
#

tan 59= 39/x

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opp=39

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adj=x

lofty kelp
#

yes

lilac lantern
#

x=39/tan(59)

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tan(59)=1.66427

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in degrees, maybe you have your calculator in radians

lofty kelp
#

I have it in degress

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dont u times 39 on each side?

lilac lantern
#

39/1.66427=23.433

lofty kelp
#

to cancel it out?

lilac lantern
#

no you have to divide by tan 59

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in both sides

lofty kelp
#

O

lilac lantern
#

wait i can show you

lofty kelp
#

ok, thank you

#

?

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I got it, thanks'

dry berry
#

hmmmm

lilac lantern
#

@lofty kelp

dry berry
#

can anyone help?

lilac lantern
#

really easy problem

#

you know what a consecutive number is right?

dry berry
#

like x and x+1?

lilac lantern
#

yup

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so just do the difference of those cubes

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and thats equal to 1812

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did you understand or should i write it?

dry berry
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(x+1)^3 - x^3 = 1812?

lilac lantern
#

well

proud burrow
#

@dry berry yes solve it you will get answer

lilac lantern
#

x^3-(x+1)^3=1812

#

if that doesnt work

#

try the one you put

#

or viceversa

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just in case

dry berry
#

the one i put only has complex solutions

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that's weird

lilac lantern
proud burrow
#

@dry berry don't use vice versa case it's given difference of cubes of two consecutive terms is 1812 which is positive if you use x3-(x+1)3 then answer would be negative

dry berry
#

that one too lmao

#

maybe the question is wrong...

lilac lantern
#

use this

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you will get two answers

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one positive one negative

lilac lantern
#

you would get 24.07 and -25.07

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and it also says integers

proud burrow
#

So use 24 as answer

dry berry
#

ohhh

proud burrow
#

So consecutive term will be 25

lilac lantern
#

yeah but 24+25 isnt any of the options

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and also the answer we get isnt an integer

dry berry
#

man i've typed in wrong function 😳

alpine sable
#

is it free here already?

proud burrow
#

@alpine sable yes

alpine sable
#

can somebody help me with this question

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😦

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do we need to use differentiation here?

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if yes is there any other method

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?

hollow ravine
#

how to find the volume

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they r hollow

dry berry
alpine sable
#

since i haven't learnt differentiation yet

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😦

proud burrow
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@hollow ravine use formula pi (outter radius square - inner radius square) h

dry berry
#

when it comes to tangent of a curve we often use defferentiation

alpine sable
#

fine the volume of the bigger one

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fine the volume of the second one

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and subtract them

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nah nvm

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im wrong

dry berry
ocean sealBOT
#

gansta

alpine sable
#

i don't understand cuz i haven't learnt yet

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sorry

hollow ravine
#

@proud burrow I did it and I got it wrong so idk

dry berry
dry berry
alpine sable
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there is no answer

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thats why

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i mean no answer sheet provided

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what about this 😦

proud burrow
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@hollow ravine this is the formula

hollow ravine
#

ok I will try it now

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but how do you get the height

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since they only give the length

proud burrow
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Length is the height

hollow ravine
#

oh

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ok

dry berry
ocean sealBOT
#

gansta

alpine sable
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why tho

dry berry
#

since the graph goes through the point (0;14)

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so x=0 and y =14

alpine sable
#

i think there might be smtg wrong

hollow ravine
alpine sable
#

cuz thats literally -14

hollow ravine
#

@proud burrow this is what I got

dry berry
#

oops

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sorry

alpine sable
#

there must be smtg wrong with the question

dry berry
#

$-2h^2 - 6 =-14$

ocean sealBOT
#

gansta

dry berry
#

now is correct lol

alpine sable
#

this teacher is ridiculous

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she simply sets question

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and didn't provide us with any answer

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D:

ember nest
#

Find the quadratic polynomial the sum of whose zeroes are root2 and their products is -12 . Find the zeroes too.

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help

hidden horizon
#

use vietas formulae man

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let zeroes be x1 and x2

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x1 + x2 = root2
x1.x2 = -12

dry berry
ember nest
#

ful explanation

hidden horizon
#

so polynomial will be x^2 - root2x - 12

alpine sable
hidden horizon
ember nest
#

nope bro

alpine sable
ember nest
#

in india it's different

hidden horizon
ember nest
#

but i forgot

hidden horizon
#

take class 10 ncert

ember nest
#

cbse?

alpine sable
#

how does that work but i think thats correct

hidden horizon
alpine sable
#

thanks ❤️ @dry berry

ember nest
dry berry
hidden horizon
dry berry
#

since (-2)^2 =4

ember nest
hidden horizon
#

wait

alpine sable
ember nest
alpine sable
#

i mean how to get the first step

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😅

hidden horizon
#

see n understand coz vieta's used everywhere

ember nest
#

thanks bro

hidden horizon
ember nest
#

: D

dry berry
alpine sable
#

i don't think so tho since the graph should only work under mapping x=2

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so h must be 2

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only

dry berry
#

since the graph has the function y=f(x) = -2(x-h)^2 -6

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we can put the following two points into this function

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(0;-14) and (4;-14)

alpine sable
#

oo

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o^o

dry berry
#

with x = 0 and y = -14

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that's the first case

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and x= 4 and y =-14

alpine sable
#

ooh

dry berry
#

it seems like i've missed the point (4;-14) earlier

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it those two function has the same root "h" you can only choose that root i guess?

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btw im done here

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the rest is yours

alpine sable
#

thanks a lot

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:3

nimble mulch
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Why is this solution wrong ?

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I have checked multiple solutions online and none of them have considered that y cannot be 0

muted raft
#

why would it not be 0?

proud burrow
#

@nimble mulch use second equation as whole numerator >=0

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@muted raft if it's zero then it would be infinite

muted raft
#

$\frac{0}{1+0^2} = \frac{0}{1} = 0$

ocean sealBOT
rustic hatch
#

could someone help me

#

logarithmic

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والله مشكلة المدرسة

muted raft
#

apply log rules

proud burrow
#

@rustic hatch as base is 4 for both substitute both value equal then find value of x

hidden horizon
#

ull get quadratic

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simplify

proud burrow
#

@hidden horizon yes that what I ment

rustic hatch
#

what about the log

hidden horizon
#

log will go coz its same both lhs and rhs

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just like exponents when bases are equal

proud burrow
#

@hidden horizon yes

rustic hatch
rustic hatch
hidden horizon
#

cool bruh np

rustic hatch
rustic hatch
#

sohcahtoa right?

hidden horizon
#

use basic trig

hidden horizon
#

tan 30 will be x/7

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so x will be 7/root3

silk terrace
#

is this open now?

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I got this problem. How do I find for a, a that is not 0, a solution? I can not have the null-vector. The matrix on the right is the inverse of the one on the left.

rustic hatch
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@hidden horizon

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help?

hidden horizon
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16 is 4^2

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so 2x = 2(2x-6)

muted raft
hidden horizon
#

so x will be 6

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got it ?? @rustic hatch

muted raft
#

Since A is supposed to be invertible like you said

rustic hatch
#

i appreciate it

hidden horizon
silk terrace
#

for a non zero "a" and non zero vector "x"

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But I am not seeing an approach to the solution other than brute force?

muted raft
#

Hmm I think I have an idea one sec

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There is a term called involutory matrices which is what I think is here

hidden horizon
silk terrace
wary stream
rustic hatch
silk terrace
muted raft
#

det is not 0?

silk terrace
#

nope

wary stream
#

Apply that

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If you find the det and it equals 0, then the matrix is not invertiable

silk terrace
#

det is (a) and 1/a

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I know that. I inverted the matrix which can be seen on the right hand side (since a is non zero)

wary stream
#

Do you know how to find the det of a 3 x 3?

silk terrace
#

Yes. Found for both.

wary stream
#

So set the det equal to 0, and find a

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And a cannot equal that value, it can be any other value though

muted raft
#

Oh wait this is just a question about invertible matrix theorem

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Which means you can pretty much apply any of the properties in the theorem

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AKA it must have 3 pivots, it must have nullspace 0, it must be linearly independent, it must have det = 0, columns form basis, etc

silk terrace
#

I mean I am not sure on what dldh06 is refering to? Both determinants are found to be a and 1/a (of course) setting them to 0 does not do anything is it is non 0 (of course since it is invertible)

wary stream
#

Find the det of a 3 x 3

muted raft
#

Yes that should work as well

wary stream
#

This process

silk terrace
#

What 3 x 3 are we refering to and for what purpose?

wary stream
#

The LHS matrix

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And like I said, for a matrix to be invertiable, the det cannot be equal to 0

silk terrace
#

But that has already been done. The determinant is equal to a and a is then of course non 0

wary stream
#

So the solution to your problem, is a can be any value except for 0, so $a \neq 0$

ocean sealBOT
#

dldh06

silk terrace
#

yep but that is not the problem though?

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I need to find a vector x

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that solves T_a(x)=T_a^-1(x)

rustic hatch
#

@hidden horizon

silk terrace
#

(aka my first picture where the vector X=(x,y,z))

wary stream
#

But you said to find an "a" that has a solution?

silk terrace
#

A solution is not an "a". A solution is the vector

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worded poorly I see.

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i. e I need to find a vector x
that solves T_a(x)=T_a^-1(x), for "a" that is non zero

wary stream
#

So is the goal to find "a" or (x, y, z)?

silk terrace
#

(x,y,z), a not equal to 0 and (x,y,z) not equal to the null vector

wary stream
#

The thing is, if $a \neq 0$, you'll have infinity many (x, y, z) vector solutions

ocean sealBOT
#

dldh06

silk terrace
#

Yes. But which form do these vectors have. I need to argue for an approach and not just pick any random vector from brute force and show that it works

wary stream
#

I would assume RREF would be the best way to do that part

silk terrace
wary stream
#

Symbolically, keeping "a" in there

silk terrace
wary stream
#

Where is this question from?

silk terrace
#

A pratice problem. Not from a book or anything special.

devout linden
#

Hi there.

I know that if
F(x) = a cos(px) + b sin (py) [1]

Then
F''+pF = 0 [2]

But assume we don't know anything about F(x). How can we solve it from [2] to get [1]? What should i know first if i want solve it in reverse??

wary stream
silk terrace
#

No not at all. A friend was given this in a cs lin alg class. I took lin alg last year.

wary stream
devout linden
#

<@&286206848099549185>

woven dock
#

Hello vondarkness
Did you mean
f(x)= a cos(px) + b sin(px)
And
f''+p²f=0
?

viscid yacht
#

Is this channel open

#

How would i complete the square?

manic quail
viscid yacht
#

2

manic quail
#

I'd say $a=x\sqrt{2}$

viscid yacht
#

No

ocean sealBOT
#

𝔙eryhappyperson

viscid yacht
#

Im trying to complete the square

manic quail
#

So am I.

viscid yacht
#

I sis this so far

manic quail
#

I get this.

#

Which should be the same as
$$2(x+\frac{1}{4})^2=\frac{25}{8}$$

ocean sealBOT
#

𝔙eryhappyperson

blazing oak
#

Easy 2

glacial pelican
#

anyone know how to solve this?

outer elm
#

its 2 equations with 2 variables

#

a1 + 4d = 1/2
a1 + 19d = 7/9

glacial pelican
#

does that mean 15d = 3/8

alpine sable
#

can someone help

outer elm
#

5/18

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because you do 7/9 - 1/2

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how did you get 3/8

glacial pelican
#

its 7/8

outer elm
#

oh shit

#

my bad

glacial pelican
#

lol its ok

outer elm
#

yeah

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3/8

meager crescent
outer elm
#

so d = 1/40

glacial pelican
#

but how do i figure out the first 3 terms??

outer elm
#

now you plug the d in one of the equations to find a1

#

then you just go:
a1
a1 +d
a1 + 2d

meager crescent
#

3M(Milk)+5B(Bread)= 4M+4B=10

#

Therefore

#

Ooops 1sec

glacial pelican
outer elm
#

read man

glacial pelican
#

sorry

meager crescent
#

sec ill re write it @alpine sable

outer elm
#

its a system of equation

meager crescent
#

3M+5B=11

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4M+4B=10

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do u know how to do simutaneous equations @alpine sable

alpine sable
#

no

meager crescent
#

Do u know what simutaneous equations are?

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3m(3milk) 4b(4 bread)

alpine sable
outer elm
#

lmfao

meager crescent
#

lool

#

basically in order to figure out how much something is M

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1sec

alpine sable
#

wait

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brain cells hurt

meager crescent
#

Loool

#

in order to find ouut how much one thing cost

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in this case M (Milk)

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u would make the other variable (in this case bread) the same number

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what i mean

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a number that both 4 and 5 go in is 20

alpine sable
#

yes

meager crescent
#

12M+20B=44

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20M+20B=50

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now what we do is get rid of bread

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so it is

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kinda makes sense?

alpine sable
#

no

meager crescent
#

sorry did not even write properly

#

Ur goal is to find out what milk and bread cost

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in order to do this u would make one factor in this case maybe bread the same

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so u can figure out what milkk is

viscid yacht
#

I need help with 5

alpine sable
#

ohh

manic quail
#

,rotate

ocean sealBOT
manic quail
alpine sable
#

It's 4

#

Look at the solutions +2 +4 -3

stiff quiver
#

Is this channel free?

manic quail
devout linden
#

Like how come a regular f'' somehow ended up as a trigonometric function??

If i start from f(x) to find f'', i can do that. But how about in reverse??

woven dock
#

I think it's a bit too long to explain it here, please check out the wiki
https://en.m.wikipedia.org/wiki/Characteristic_equation_(calculus)

In mathematics, the characteristic equation (or auxiliary equation) is an algebraic equation of degree n upon which depends the solution of a given nth-order differential equation or difference equation. The characteristic equation can only be formed when the differential or difference equation is linear and homogeneous, and has constant coeffic...

devout linden
woven dock
#

Yea, you'll need knowledge of complex numbers to understand it

viscid yacht
#

I need help on regents practice

#

Idk how to make equation

devout linden
covert glade
#

Is any number divided by infinity defined or undefined

#

like -4/oo

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is that 0

#

or undefined

rustic hatch
covert glade
#

?

woven dock
#

hello uncle Rico you can say $$ \lim_{x \to \infty} \frac{-4}{x} = 0 $$

ocean sealBOT
#

Biscuit

timid wind
#

someone help explain this question please

#

<@&286206848099549185>

#

ping me when u can

outer elm
#

wtf looks hard

devout linden
woven dock
devout linden
#

Ahh yeahh....should be p^2

#

Okay....then i almost understand

#

Soo if it's 2 dimension, the sin px can be changed into sin py without anything to do??

woven dock
#

I don't think so, I think it's just a typo

devout linden
#

Ahh okay....after checking my book, i got misunderstanding.

However now i get it why it become like that. Thank you very much @Biscuit#5208

rustic hatch
crude eagle
#

here bro

#

with notable triangles

rustic finch
#

$7\ =\ -1.79\sin\left(\frac{2\pi}{365}\left(x-79\right)\right)+6.3$

ocean sealBOT
#

Břāđ

rustic finch
#

how do you solve the multiple angles for something like this without graphing it

tight locust
#

sin

chilly night
#

Sorry for the easy question, but I'm not good at math:

Enter a number between 1 and 100:
Enter a number between 1 and 100:```

What are the chances to win?
edgy zealot
rustic finch
shell widget
#

@chilly night 1 in 100

#

@rustic finch take everyhing to the other side and write it in the form sin(...) = (some number)

#

then take arccsin on both sides

rustic finch
#

yea, how do I get the second angle

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and other equivalent ones

shell widget
#

well sin is periodic with period 2pi

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so you just add +2npi

chilly night
shell widget
#

did u enter 3 numbers?

alpine sable
#

hello, what is -i squared

shell widget
#

complex numbers?

alpine sable
#

yeah

shell widget
#

(-i^2) = (-1)^2 * (i)^2

alpine sable
#

so just -1 then

#

thanks!

edgy zealot
sterile beacon
#

i start with 60x and 3000y

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every time i gain 100y

#

i lose 1x

#

how do i put this in equation format

rustic finch
silver bay
#

can someone help me solve this

quasi scarab
quasi scarab
quasi scarab
silver bay
sterile beacon
edgy zealot
#

@quasi scarab 176?

quasi scarab
#

yes

edgy zealot
#

Thank you bruh that made it so easy

worldly cliff
#

is this channel free?

sterile beacon
#

yes bruce

worldly cliff
#

its buce.

#

smh

sterile beacon
#

sorr

worldly cliff
#

how would i find the two points the line y=4.2 through the parametric curve

#

sorry for the bad drawing

sterile beacon
#

it was (60y-x)(3000y+100x) not 60x +3000y + a(100y-x) @quasi scarab

edgy zealot
#

Is this right ?

quasi scarab
sterile beacon
#

i did i needed the numbers in equation format

lilac lantern
quasi scarab
#

u said this: i start with 60x and 3000y
every time i gain 100y
i lose 1x
how do i put this in equation format

sterile beacon
#

yes

#

that's how it be

quasi scarab
#

and u got this : (60y-x)(3000y+100x)?? how

sterile beacon
#

bruh i thought you were a mod

#

going around telling people what to do

quasi scarab
sterile beacon
#

i didn't think i assumed

quasi scarab
#

u didnt pay attention to the rules, so i advised u to read them, i didnt go around telling ppl what to do

sterile beacon
#

I'm not going to let you ruin my fun doing math

#

so jokes on you i guess

quasi scarab
#

wdym

silver bay
#

can someone help me with these

#

im not too sure if this is math or physics

#

but its in my math class

remote heron
#

its rotational kinematics right

#

but basically math

#

which problem were you having a hard time with @silver bay

silver bay
#

all three of them

#

theres 2 more

silver bay
remote heron
#

id imagine so

silver bay
#

but im not sure if its right because i dont know gravity, should i just assume its 10 m/s^2

remote heron
#

usually yea whatever convention you use for your glass

#

sorry class

#

usually for problems like this i think youd just use g

silver bay
#

we haven't really done this before

remote heron
#

or if you all are using 10

silver bay
#

and i dont have a teacher :/ so i have no clue

remote heron
#

youre lucky theres a lot of resources for physics at this level

#

at least lecture-wise

#

if you can wrap your head around simple harmonic motion really

#

this is just a subset of that

silver bay
#

this isnt even physics 😭 its for my diffeq class and im not sure whether im supposed to do something different for that

remote heron
#

oh

silver bay
#

thats why i put it here

#

because like

remote heron
#

idk id just answer it however you can figure it out

silver bay
#

math class

remote heron
#

idk at that point id just pick the easiest way

#

since theyre not really clear

#

you can state/solve the SHM equation

#

which is uhh

silver bay
#

2pi sqrt(L/g) right

remote heron
silver bay
#

for period

#

oh

#

what is that 😭

remote heron
#

wait thats nonlinear

#

this is without small angle

silver bay
#

oh nvm i found it in my book

remote heron
#

ye

silver bay
#

and theta = sin(theta) for small angles

#

hmm

remote heron
#

i mean yea

silver bay
#

or like

#

approximation

remote heron
#

its not really exactly clear what youre supposed to do

silver bay
#

yeah :/

#

i have no clue

remote heron
#

but it seems like youre on the way

#

idk if you state the original one, then the small angle approximation

#

maybe if you feel like solving it

#

so solve the IVP on that solution, then use calculus to maximize it

#

thats probably overkill for what this problem is asking but i guess thats the mathy thing to do

silver bay
#

whats an IVP

#

sorry

remote heron
#

the second question i think is an IVP

#

uhh

#

initial value problem

silver bay
#

oh

#

ok yeah

#

it is

remote heron
#

since they give you an initial position and velocity

silver bay
#

ummm

remote heron
#

for a second order diff eq

#

you can solve it fully

silver bay
#

ok ok makes sense

edgy zealot
remote heron
#

then whatever procedure you typically use for maximizing things

silver bay
#

so i just use the equation, plug in a value for length, and solve?

remote heron
#

i would state the equation, state the small angle approximation

#

without subbing in anything

#

then for part 2, use the given length, IV's state the specific SHM eq for that situation

#

then do calc stuff to maximize

#

or whatever handwavey 'it is known' blah blah stuff youre allowed to do for periodic functions

#

does that all make sense

silver bay
#

um

#

kind of?

#

im not really sure tbh

remote heron
#

which part seems confusing

silver bay
#

so

verbal sigil
#

Hi guys, im using excel and im trying to represent a large amount of data, i thought a line graph might be the best option but im struggling to create it on excel, would anyone be able to assist me? Thanks

silver bay
#

say this equation but with a sin(theta) instead of theta

#

then i say because its a small angle, sin theta~~theta

remote heron
#

idk thats probably overkill but i would state it just for shits and giggles

silver bay
#

oh okay

#

and hten

#

i plug in the length

#

and 10 for gravity

remote heron
#

i mean they're constants so you can leave them for as long as you want but whatever works

silver bay
#

and then i solve it?

#

as a second order differential equation

remote heron
#

id solve it fully with all constants just left but thats just me

silver bay
#

oh okay

remote heron
#

so you have a generic solution

#

might be useful later

silver bay
#

okay makes sense

remote heron
#

😄

silver bay
#

sooo

#

how would i solve the equation 😭

remote heron
#

is this characteristic polynomial

#

i forget a lot of diff eq

silver bay
#

im not too sure

#

its second order ordinary

#

actually

#

i have no clue

remote heron
#

lol im gonna have to review

alpine sable
#

yknow how differentiating velocity gets acceleration and differentiating that gets displacement, what does integrating velocity get you?

alpine sable
#

oooo so its like a cycle

silver bay
#

yeah

alpine sable
#

thank u

silver bay
#

its the inverse pretty much

#

np

remote heron
#

shit i might have to find my notesn

#

i did a whole project on SHM in ODE

silver bay
#

should i solve it with a laplace transform

#

because thats my current unit

#

i have no clue whether that makes any sense though

remote heron
#

if you know how yea

silver bay
#

ew its like

#

really nasty

remote heron
#

haha

silver bay
#

random square roots and stuff

verbal sigil
#

will anyone be able to help on statistics?

remote heron
#

im gonna give it a go really quick

#

i swear i remember this stuff

plush goblet
#

hey which channel I can ask question ?

#

is here good ?

misty path
#

I need help. What is 1+5

remote heron
#

yall can u not see were having a conversation

misty path
#

no

remote heron
#

please use a channel that doesnt have a active ppl in it

misty path
#

Bruh

silver bay
#

broo i have a physics ap test tomorrow 🤯

remote heron
#

damn i forgot how involved solving these things can be

silver bay
#

can you say what you got for the first one once you finish

#

because i did it

#

like the easy way

#

but i have absolutely no clue if its right

remote heron
#

so

#

you use

#

characteristic polynomial

#

you have imaginary solutions

#

but the imaginary part falls away when you determine the coefficient?

remote heron
silver bay
#

ehh idk

#

i mightve done it wrong

remote heron
silver bay
#

idk if its 19 or 38

#

because

#

like

#

it says returning to original posiiton

#

not a full swing

remote heron
#

that is a full swing

silver bay
#

oh

#

wait

#

thats what makes it tick

#

that or its mirror image

#

so wouldnt that happen twice in one period

remote heron
#

were getting the position function arent we

#

so it should be positive, become negative at the bottom, be maximum negative on the other side, then positive again when it comes back

#

i am dumb so grain of salt but i dont think this function is giving vertical displacement

#

i think its angular displacement

cloud kiln
silver bay
#

it is

#

i am so confused

remote heron
#

?

silver bay
#

well

#

i dont know how the diffeq plays into this at all

silver bay
#

i just used the equation for period

remote heron
#

you can use whatever you want

silver bay
#

T=2pi sqrt(L/g)

#

but that gives you the period

remote heron
#

unless the question is specific

silver bay
#

which is the time for a right swing and a left swing

remote heron
#

i mean you can do it however you want i think

#

if you are not comfortable with that way find the roots of the velocity equation?

#

which is gonna be the same thing but longer

silver bay
#

what would the velocity equation be though

#

sorry im really clueless about this

remote heron
#

how do you get the velocity given a position equation

silver bay
#

derivative?

#

do i even have a position equation though

remote heron
#

you solved the diff eq right

silver bay
#

no

#

i couldnt figure it out

remote heron
#

alternatively

#

uhh

#

there is a way to turn a second order into a first order right

silver bay
#

ah shoot gtg can i ask again in like half an hour

remote heron
#

if you just want the first derivative

remote heron
#

just define the first derivative as a function

#

idk im being dumb

#

but i wanna review how to solve it now

#

just lazy

strong furnace
#

the way they do it in introductory physics is multiply left side by dx/dx or d(theta)/d(theta)

#

you get a variable seperable ODE I think

#

and you use the relation to solve it

tawdry mantle
#

how does the first equation turn into the second equation?

#

<@&286206848099549185>

remote heron
#

you shouldnt ping right away

tawdry mantle
#

oh sorry

remote heron
#

its a two step algebraic process

#

you should try to track it, its good practice

#

but its division and exponentiation

tawdry mantle
#

i tried a few ways

#

can't figure it out

ionic jewel
remote heron
#

start by dividing

#

then exponentiate

tawdry mantle
#

ok i'll give it another shot

#

@remote heron @ionic jewel I think I got it lol

remote heron
tawdry mantle
#

divide both sides by 10

then turn the log into something like... little to the power of right equals middle

#

thanks 🙂

remote heron
#

😄

alpine sable
#

I have N=20, k=4 (m1=4, m2=8, m3=12,m4=7) and SSB=22. How do i find the value of SSW? I tried SST=SSB +SSW. And MSB=SSB/K-1 (4) but i'm stuck.

loud folio
#

Help pls I’ll give you a 🍪!

civic crypt
#

Which of these looks like an area formula?

scenic sable
timid wind
#

hey, can someone help me with this question

scenic sable
#

why does 0^0 equal 1

timid wind
scenic sable
#

ik that any numebr to the zero power equals 1

#

but i thing google is tripping

noble sinew
gilded gazelle
#

how tf do i solve this... like this was never taught lol

#

<@&286206848099549185>

silver bay
#

how would that work?

shut elk
#

@gilded gazelle i think we want some system of equation to solve for how many weeks it takes to make 10,000$ correct? EDIT: make 10,000$ more than its expenses

#

so it's linear, and linear relationships have form $y = kx$ right?

ocean sealBOT
shut elk
#

furthermore, the average weekly income is roughly 4,500, the average weekly spend is roughly 3,200.

gilded gazelle
#

ah ok i get it now

#

i knew the answer but i couldnt figure out why

#

i didnt use averages

shut elk
#

what was it?

#

how did you solve it?

gilded gazelle
#

i am studying, this has an answer sheet and once you mentioned averages i solved it by just getting both and doing simple math

spending + 10000 = revenue

#

so this

shut elk
#

well that's not what i was thinking

gilded gazelle
#

so like revenue = spending + 10000

#

they count that as well i think

shut elk
#

1 mo

#

ye it's the same

strong furnace
silver bay
#

i'm not sure what you meant tbh

shut elk
#

i know it's the same thing bigweld, but my thought process was 4500x-3200x=10000 hence 1300x=10000

#

i'll drop out the channel

#

sorry t o interrupt.

strong furnace
silver bay
#

yeah, its just theta'' = -g/L theta

strong furnace
#

but this is a first order differential equation in v or dx/dt

silver bay
#

uhhh

#

yeah

#

i think

strong furnace
#

and you know condition at some point

silver bay
#

yeah i think

#

wait

#

can i check number 1 with you

#

because i think i dont need the diffeqs for that

#

but i also dont know if i did it right

strong furnace
#

sure

silver bay
#

i just used the shm equation

#

$$T = 2 \pi \sqrt{\frac{L}{g}}$$

ocean sealBOT
silver bay
#

L = 0.6m and g=10m/s^2

#

so i get T=1.53906 s

strong furnace
#

if you are allowed to use this

#

then that is alright

#

but this result requires differential equation

#

so if this is a result you're allowed

silver bay
#

I'm not sure if im allowed to use it

strong furnace
#

you have the time period of oscillation

silver bay
#

so i should probably use a differential equation

strong furnace
#

if this is an introductory physics course

#

they probably don't expect you to solve the diff eq

silver bay
#

its a differential equations coures

#

*course

#

like a really intro level one but we've covered the things i should know to solve it

#

like 2nd order linear

strong furnace
#

you can solve 2nd order differential equations?

silver bay
#

i think? i dont really remember 😭

strong furnace
#

general solution Ae^(a_1x)+Be^(a_2x)?

silver bay
#

yeah i think so

#

this stuff right

strong furnace
#

yeah

silver bay
#

okayy, so

#

my equation is

#

$$\theta '' = -\frac{g}{L}(\theta)$$

#

i think?

#

or that should be a sin(theta) on the right but im using small angle approx

#

i should probably just keep it as sin

strong furnace
#

nah they use theta to get the result

silver bay
#

oh okay

ocean sealBOT
silver bay
#

im confused about how id solve that though

#

should i just plug in numbers and then try>

#

but then i get like

#

okay if i plug in numbers

#

i get

#

$$\theta '' + \frac{10}{0.6} \theta = 0$$

ocean sealBOT
silver bay
#

and to factor that i get like imaginary numbers right

strong furnace
#

yes

silver bay
#

sooo

#

uh

#

$$(D+\sqrt{\frac{10}{0.6}}i)(D-\sqrt{\frac{10}{0.6}}i)\theta=0$$

#

oops

#

no

ocean sealBOT
silver bay
#

okay that

strong furnace
#

yes

silver bay
#

so my roots are

#

$$\pm \sqrt{\frac{10}{0.6}}i$$

#

so its e raised to that times x

ocean sealBOT
strong furnace
#

theta in this case but yes

silver bay
#

ok yeah makes sense

#

should i use eulers formula?

strong furnace
#

to get it in the desired form you need to actually do that

silver bay
#

okay sounds good, so itll be

#

wait what is my dependent variable here

#

oh nvm

#

theta is dependent, t is independent

silver bay
#

because theta is the dependent variable

strong furnace
#

ohh yes

#

my bad lol

#

I switched them up

#

in my head

#

it would be t

silver bay
#

$$\theta=c_1 cos(\sqrt{\frac{10}{0.6}}t)+c_2 sin(\sqrt{\frac{10}{0.6}}t)$$

#

does that look right? im not sure if i did the euler thing right

ocean sealBOT
strong furnace
#

does not look right

silver bay
#

oh

#

:/

strong furnace
#

e^(wit) would be cos(wt)+isin(wt) right?

silver bay
#

i think so

strong furnace
#

don't you think there are two terms missing from your solution ?

silver bay
#

ummm

#

i dont think so?

#

im not sure

strong furnace
#

you c1.exp(iwt)+c2.exp(-iwt) right?

silver bay
#

yeah

#

,wolf solve differential equation y''+10/0.6 y=0

silver bay
#

yeah

#

so i think what i have is right

#

wait no

#

uhhh

#

wait

#

no

#

i need to check again

#

ok yeah i think what i had is right then

#

i think the other two terms cancel out or something?

strong furnace
#

I am really tired

silver bay
#

its fine lol dw

#

i have no clue what im doing at all

#

but i kind of remembered that

strong furnace
#

ok so ignoring all of that

#

you have this right?

silver bay
#

i think so

#

i have the equation for theta

#

so i have to find out how many times it equals 0 between t=0 and t=30

#

i have no clue how to do that

strong furnace
#

you can use something called R-method to convert this into a single sinusoidal function

silver bay
#

oh

#

i dont know if im supposed to do that

strong furnace
#

why not?

#

it is just manipulation of terms to relate with sin(A+B)

silver bay
#

oh okay

#

i guess we could

strong furnace
#

so you would get a sin function with the same period

silver bay
#

that makes sense but at the same time we have like constants right

#

and i dont knwo what the constants are

strong furnace
#

the constants affect the phase and amplitude of the sinusoid not the period

silver bay
#

oh okay makes sense

strong furnace
#

so after you have theta as a function of time with period this

#

you can use that as time period

#

and now you have a simple arithmetic problem with time period total time and number of ticks

silver bay
#

makes sense

#

so what would the method be?

strong furnace
silver bay
#

the R-method you mentioned

strong furnace
#

the idea is to divide by sqrt(c1^2+c2^2) and you'll have terms similar to he terms in sin(A+B)

#

but here's a link for more info

#

The trigonometric R method is a method of rewriting a weighted sum of sines and cosines as a single instance of sine (or cosine). This allows for easier analysis in many cases, as a single instance of a basic trigonometric function is often easier to work with than multiple are. The R method is most often used to find the extrema (maximum and mi...

silver bay
#

oh

#

i think im overthinking this

#

theres no way we have to do that

strong furnace
silver bay
#

well

#

its nowhere in our textbook

#

and i really dont know how im supposed to solve this but theres no way its supposed to be this long

#

because i have 10 of these as 1/10 of my assignment

strong furnace
#

I mean if all of them use

#

it

#

you can just derive it once

#

and use the result

silver bay
#

i guess

#

i dont know

strong furnace
#

also R-method is trigonometry so precalculus that would be a pre-requisite, no?

silver bay
#

yeah i guess

#

i dont think ive ever seen it though

#

in precal

#

but i could be wrong because i took precal like

#

3 years ago

#

almost 4

#

how would i do this though

#

because my constants are really arbitrary

#

theres no given values

#

these are my questions

strong furnace
#

you have to use the condition

#

like they say it is released from rest

#

at an angle of .1 radians

#

so that is your initial conditions

silver bay
#

oh

#

wait no for 1

strong furnace
#

for 1 the constants don't matter

#

since the time period does not depend on the constants

strong furnace
silver bay
silver bay
#

the equation i got?

strong furnace
#

the relation you get yes

#

rest is information corresponding to derivative

alpine sable
#

I know this is a math channel but can someone help me in my english please?

strong furnace
silver bay
#

since the left hand right now is theta

strong furnace
#

0 for initial condition

#

ohh you meant after differentiating

#

yes

edgy zealot
silver bay
#

does this look like its of any use

#

because its asking for the equation of motion for #2

#

so i just say the thing with theta ''

#

?