#help-41

1 messages · Page 24 of 1

split sail
#

i've gone through multiple methods but i keep missing some crucial fact here and there

spark dragon
#

okay for the two planes take the constant to the other side

#

u get 2x -y + 3z -1 = 0

#

and x+y-z -2 = 0

#

we shall denote these as P1 and P2

#

now the general form for a plane passing through the line of intersection of these two is

#

P1 + AP2 = 0

#

where A is some arbitrary constant

#

u with me till here?

split sail
#

yeah

spark dragon
#

yep

#

so now

#

substitute P1 ans P2

#

tell me what u got

split sail
#

interesting

#

is there a reason this works?

#

well obviously there is

spark dragon
split sail
#

but what makes P1+AP2=0 a family of planes sharing a line of intersection

spark dragon
#

writing it here will be confusing

split sail
#

i see

spark dragon
#

similar to vectors

split sail
#

right

spark dragon
#

because they re linearly dependant

split sail
#

in fact you kind of are working with vectors

spark dragon
#

if thats the right word

spark dragon
split sail
#

the cross product of two orthogonal vectors is always 0, even if you scale one of them

spark dragon
#

correct

split sail
#

that makes sense

spark dragon
#

mhm so we cud just write any plane as AP1 + BP2 = 0

split sail
#

so really I could say AP1+BP2=0 as well for some arbitrary A and B ≠ 0

spark dragon
#

but since we dont want to have

split sail
#

lol yeah exactly

spark dragon
#

two variables

spark dragon
#

so for simpler calculation just divide by A

split sail
#

yeah it doesn't really matter at the end of the day

spark dragon
#

u get B/A which u can take as some arbitrary constant

split sail
#

it's all arbitrary anyway

spark dragon
#

now back to the question

split sail
#

right

spark dragon
#

P1 + AP2 = 0

#

have u substituted p1 and p2

#

?

split sail
#

i'll do that now

spark dragon
#

mhm

#

what u can do is

#

after expanding it

#

u can take the x term common, y term common , z term common

spark dragon
split sail
#

sorry i don't have access to writing the computation rn but i trust the concept

split sail
#

so when i get the means i'll do the computation

spark dragon
#

no need to

#

if u want ill write this one second

#

(2x-y+3z-1) + A(x+y-z-2) = 0

#

2x -y + 3z -1 +Ax + Ay -Az -2A = 0

#

x(2+A) + y(-1+A) + z(3-A) -1 -2A = 0

#

notice this is just another plane equation

#

but with arbitrary direction ratios ( because of A)

#

clear till here?

split sail
#

yep

#

i'm following

spark dragon
#

mhm

#

now we need to find A

#

simple we just need another condition

split sail
#

which is the point given

spark dragon
#

yep

#

just substitute x y z of the points

split sail
#

(-1,2,1), substitute

spark dragon
#

u will get A

#

problem solved

split sail
#

damn

#

that's a nice result

#

not that i know what A is

#

but that's a nice method

spark dragon
#

yes very quick

split sail
#

better than my cross products lol

spark dragon
#

u can also use it when they say "its perpendicular to one plane" too

#

because u know the normal vector of that plane in terms of A

#

just use the dot product condition

#

u can find A

split sail
#

right

#

couldn't i also find it for any angle

spark dragon
#

sure

split sail
#

using that one cos thing

#

i'm not exactly sure what i would use but i have a vague idea

spark dragon
#

do what u wud when finding angle between two planes

#

same idea

split sail
#

exactly

#

alright

#

makes perfect sense

#

thanks so muc

#

h

spark dragon
#

np

split sail
#

.close

amber waspBOT
#
Channel closed

Closed by @nocturne edge

Use .reopen if this was a mistake.

#
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.

solid mortar
amber waspBOT
solid mortar
#

,rotate

grizzled pagodaBOT
solid mortar
#

We have to solve for 1/d0

#

This what I got anyone wanna help check

#

There’s no answer key and I feel wrong

spiral zealot
#

can you show the full question and full work

jaunty shale
#

yes, show all

#

cuz what you found is apprently wrong

#

thats 1/f - 1/di, so its 1/d0

solid mortar
#

My phone died sorry

split sail
#

i think you did 1/d_i - 1/f instead of the other way around

solid mortar
#

Oh god I’m dumb

#

You’re right

#

Give me a minute

split sail
#

yes

#

first thing i saw

#

i was very confused

solid mortar
#

It’s 1/d1 right

#

I just wrote the 1 and 1/1 to make the cross multiplying easier

spiral zealot
#

oh, sry misread the initial values

#

and the 1/1 was confusing

split sail
#

i still dont understand but i get the hint of what you did

jaunty shale
#

another big mistake is

#

should be (x-1)

solid mortar
#

You’re right

#

Imma just redo the whole problem I made too many errors

jaunty shale
#

no, just change that to (x-1)

#

and carry on the work

#

when you arrive to the final expression, multiply it by -

#

cuz what you did was 1/di - 1/f, which is -1/d0

split sail
#

i was just about to say this

jaunty shale
#

😛

split sail
# solid mortar

if this was right, all you had to do was "take the negative out"

solid mortar
jaunty shale
#

noicely done

solid mortar
#

Ah thanks

#

This was a problem from last year I was helping a friend with took me too long

amber waspBOT
#

@solid mortar Has your question been resolved?

amber waspBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

#
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.

wraith shale
amber waspBOT
wraith shale
#

14b please

#

Here is the marking scheme but I don't understand how does this line come out

wraith shale
#

only one x intercept?

split sail
#

f(x)/(x+1) = 0

wraith shale
#

assume x-8 is one of the factors. f(x)/(x-8) will also be zero?

split sail
#

of course

#

its using the factor/remainder theorem (might wanna recheck the name)

wraith shale
#

oh okay

#

thank you very much

#

have a good day sir/madam

split sail
#

you too :)

wraith shale
#

.close

amber waspBOT
#
Channel closed

Closed by @wraith shale

Use .reopen if this was a mistake.

#
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.

ionic zodiac
#

how can i do this?

amber waspBOT
ionic zodiac
#

chaaaaaaaaaaaaaaaaaaaaartbittttttttttttttttttttttttttttttttttttttttt

weak zinc
#

Waterrrrbeeeammmmmm KL1Cuddle

#

(I’m dying and about to sleep bcaForgiveBeg3)

ionic zodiac
weak zinc
#

You’ll have to catch me first leavechat

weak zinc
#

Anyways, a TL;dr is that you may wanna consider what you know about cdfs GentleHug

ionic zodiac
#

and the function must be positive over the interval?

weak zinc
#

But related to that, that implies that as x goes to infinity, then F(x) should have a limit of 1, riiiiggghhtttt catLove

ionic zodiac
weak zinc
ionic zodiac
#

y the limit equals 1?

weak zinc
#

Because $F(y) = \int_{-\infty}^y f(t) \dd t$, where $f$ is the pdf

grizzled pagodaBOT
#

@weak zinc

weak zinc
grizzled pagodaBOT
#

@weak zinc

ionic zodiac
weak zinc
#

GentleHug happy with that?

weak zinc
#

Cool, so bear in mind you wanna force the limit $\lim_{x\to\infty} e^{-kx}( e^{\alpha x} - 1)^2 = 1$

grizzled pagodaBOT
#

@weak zinc

weak zinc
#

How would you do it Ehehe

#

(Maybe think about expanding and rewriting that way pikathink remember that k and alpha are positive)

ionic zodiac
#

$lim_{x\to\infty}\left(e^{\left(-kx+\alpha x\right)}-e^{kx}\right)$

grizzled pagodaBOT
#

water beam

weak zinc
#

Forgot to expand first SCcattokiss

ionic zodiac
#

loh

#

i didnt see the square

weak zinc
#

nyasSnuggle now you do Hehe

ionic zodiac
#

$e^{\left(-kx+\alpha^{2}x^{2}\right)}-2e^{\left(\alpha x-kx\right)}+e^{-kx}$

grizzled pagodaBOT
#

water beam

ionic zodiac
#

i think

weak zinc
#

SCsadkittyNO careful!

#

Remember that (e^{alpha * x})^2 is e^{2alpha * x} by rules of exponents SChuggies

weak zinc
amber waspBOT
#

@ionic zodiac Has your question been resolved?

amber waspBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

amber waspBOT
#
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.

stuck lily
#

hi can somebody help me with this logic problem? if i can just get the right propositional logic equation i can probably turn it into a circuit myself

stuck lily
#

for a it should be q or r and neg p and q for b

amber waspBOT
#

@stuck lily Has your question been resolved?

jaunty shale
stuck lily
robust lagoon
#

im dying to C u rn

#

haha

jaunty shale
#

expression (b) evaluates to p* when q is true

#

thats all you need to work out (c)

amber waspBOT
#

@stuck lily Has your question been resolved?

jaunty shale
#

i gtg, i wont be here if/when you come back

#

so i'll share with you what you should find

#

compare

#

,, M(p,q,r) = \lnot(q \lor r) , \lor , (q \land \lnot p)

grizzled pagodaBOT
amber waspBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

#
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.

cerulean hazel
amber waspBOT
cerulean hazel
#

Totally forgot the process for part a)

#

IIRC do I need to integrate it within the domain?

#

that being 1 -> e^3?

little dagger
#

its continous function

#

so 1/k ln(e^3) = 1

amber waspBOT
#

@cerulean hazel Has your question been resolved?

cerulean hazel
#

ive done so in the past iirc

plain hare
#

u wud integrate the probability density function to find the cumulative distribution

shadow stump
#

you need to integrate the PDF to get the CDF. but in this case you are given the CDF to begin with

amber waspBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

#
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.

keen pawn
amber waspBOT
keen pawn
#

I can use any proof writing method for this

#

Direct proof?

#

I'm kind of lost

#

I know what I have to do

#

not too sure of how to do it

inland pulsar
pseudo crescent
#

do you recognize the relation of 120 to 5?

inland pulsar
#

5!? lmao

pseudo crescent
#

you could start with something simpler maybe, say I give you a product of 2 consective numbers, what number can you guarantee it will be divisible by?

inland pulsar
#

2!? opencry

pseudo crescent
keen pawn
keen pawn
#

like I know that $120 = 1 \cdot 2 \cdot 3 \cdot 4 \cdot 5$. And that I have to use that fact

grizzled pagodaBOT
#

Veni, vidi, perii is not f(wai)

keen pawn
#

but not sure of how to formalise it without modular arithmatic

pseudo crescent
#

you could prove that 2^3, 3 and 5 all divide the product

keen pawn
#

let $n\in \Z$. We now want to prove $120 \mid (n-2)(n-1)(n)(n+1)(n+2)$

grizzled pagodaBOT
#

Veni, vidi, perii is not f(wai)

keen pawn
#

hmm, prime factorisation would probably help a bit

pseudo crescent
#

yes, indeed

#

have you already proven something like this?
If gcd(a, b) = 1, a | n and b | n, then ab | n

#

or at least if a and b are primes

keen pawn
#

yup

pseudo crescent
#

okay, thats cool

keen pawn
#

$120 = 2^3 \cdot 3 \cdot 5$

grizzled pagodaBOT
#

Veni, vidi, perii is not f(wai)

pseudo crescent
#

if you can prove that 2^3 divides n, 5 divides n and 3 divides n, then you can conclude that 120 divides n

keen pawn
#

Yeah, pretty much

pseudo crescent
#

i actually just got a crazy idea

#

you already proved that binomial coefficients are integers, right?

#

or was it fungus

keen pawn
#

We wish to prove that $120|(n-2)(n-1)n(n+1)(n+2)$. To do this it's sufficent to prove that $2^3 \mid (n-2)(n-1)(n)(n+1)(n+2) \land 3|(n-2)(n-1)n(n+1)(n+2) \land 5 \mid (n-2)(n-1)(n)(n+1)(n+2)$. We asume two cases, first wherein the first number is even. so we have (2n-2)(2n-1)(2n)(2n+1)(2n+2). It's evident that $8|(2n-2)(2n-1)(2n)(2n+1)(2n+2)$.

grizzled pagodaBOT
#

Veni, vidi, perii is not f(wai)

pseudo crescent
#

okay, that's the first case

#

the second case is a bit harder

#

maybe avoid using the same variable twice tho

#

Some lemma like:

Among n consecutive integers, at least 1 is divisible by n

would be helpful

keen pawn
#

Yeah I know that lemma but I haven't proven it yet , so catshrug ]

pseudo crescent
#

I think it's worth to prove it as a seperate lemma

#

otherwise you will have to do 3 proofs of the same lemma

#

one for 2 and 4, one for 5 and one for 3

pseudo crescent
keen pawn
#

I can't use induction

pseudo crescent
#

Why blobcry

keen pawn
#

Haven't done it at uni yet

pseudo crescent
#

is this yorur homework or sth?

keen pawn
#

no

#

Just trying to get ahead of my class

#

If I finish this I'll be 2 chapters ahead

pseudo crescent
#

Formally proving this thing without induction will be tough

keen pawn
#

hmm

#

,w (n-2)(n-1)n(n+1)(n+2)

keen pawn
#

so I have to show $120|(n^5-5n^3+4n)$

grizzled pagodaBOT
#

Veni, vidi, perii is not f(wai)

keen pawn
#

yeah, I'll skip this for now then

pseudo crescent
#

you also covered no modular arithmetic?

keen pawn
#

Whatever hammack has done

pseudo crescent
#

you could go around it by using remainders after division by 5

#

there are 5 possible remainders

#

0, 1, 2, 3, 4

#

assume that there is no number divisible by 5

#

then that reduces to 4 possible remainders

#

1, 2, 3, 4

#

by pigeonhole, one of the remainders will be there twice

keen pawn
#

Hmm, yeah

pseudo crescent
keen pawn
#

mhm

#

Got it

#

Thanks!

#

.close

amber waspBOT
#
Channel closed

Closed by @keen pawn

Use .reopen if this was a mistake.

amber waspBOT
#
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.

vocal hearth
#

whats meant by a parametric plane curve?

shadow stump
#

it's a curve which is given in the form (x,y) = (f(t), g(t))

vocal hearth
#

oh ok tysm

#

.resolve

#

.close

amber waspBOT
#
Channel closed

Closed by @vocal hearth

Use .reopen if this was a mistake.

#
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.

vocal hearth
#

Normal Circular motion is given by the movement of an object in a circular orbit. More specifically, its speed remains constant, yet it is the angular velocity that makes the linear velocity change every time.

vocal hearth
#

whats meant by angular velocity?

#

and linear velocity

shadow stump
#

we can think of describing the position of an object moving in a circle by the angle it makes with a line (usually the positive x-axis). then the angular velocity is the rate of change of that angle

#

the linear velocity is the derivative of the position vector

slim pelican
#

angular velocity is the rate at which the object orbits around the centre (ω). linear velocity is a tangential velocity vector on the orbit (v)

vocal hearth
#

so, angular velocity is the rate of change of an angle created with a line

#

?

slim pelican
#

yes

vocal hearth
#

ok thank you

#

.close

amber waspBOT
#
Channel closed

Closed by @vocal hearth

Use .reopen if this was a mistake.

vocal hearth
#

with change every time

#

is every movement on the circle in the constant speed right

#

.reopen

amber waspBOT
#

vocal hearth
#

"the curvature in circular motion is inversely proportional to the radius and directly related to the centripetal acceleration of the particle."

#

whats meant by inversely proportional

alpine flower
#

if the value of one quantity increases then the value of other quantity decreases

#

their product is constant

vocal hearth
#

huh

vocal hearth
alpine flower
#

say x is inversely proportional to y

#

if the value of x increases, the value of y decreases and vice versa

#

k is a constant

vocal hearth
#

oh i see

split sail
#

if w is constant yes

vocal hearth
#

ok

#

thank you

#

.close

amber waspBOT
#
Channel closed

Closed by @vocal hearth

Use .reopen if this was a mistake.

vocal hearth
#

.lose

#

.close

#

??

amber waspBOT
#
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.

slow tapir
#

hey, i have such question: Find 2 orthonormal vectors x,y so that span{x,y} = span{(0,1,1), (1,2,3)}
I found the answer on stack exchange as in the picture, but i kinda dont understand, the intuitive meaning behind it. I know that it comes from gram-schmidt, but id like to understand it intuitevly

indigo cloud
#

iirc on the wikipedia article for gram schmidt there is the picture

#

which shows geometrically what the vectors v1,v2,u2 are

pseudo crescent
#

I'd also try searching on youtube, animated stuff can be easier to understand

#

and i'm pretty sure there is someone who tried to animate it

amber waspBOT
#

@slow tapir Has your question been resolved?

amber waspBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

#
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.

cursive knoll
#

can i use synth division on this?

amber waspBOT
inland pulsar
#

Yes you can

#

Tho I'm gonna recommend checking for some in your head and also use rational root theorem

elder harbor
#

u used synthetic division, alright

#

,w expand (x+5)(x^2 + 1)

grizzled pagodaBOT
elder harbor
#

looks good

cursive knoll
elder harbor
#

no

#

try

#

(x+5)(x - i)(x+i)

#

,w expand (x+5)(x - }i)(x+i)

grizzled pagodaBOT
elder harbor
#

@cursive knoll have they taught u this

#

$a^2 + b^2 = (a + bi)(a-bi)$

grizzled pagodaBOT
cursive knoll
#

probably

elder harbor
#

sorry i didnt notice the complex in the title

#

(x+5)(x+i)(x-i)

#

rty pozl

cursive knoll
#

wait is this

#

using the 4i in the divisor for synth?

elder harbor
#

u can do that

#

but i'd rather not

inland pulsar
elder harbor
#

invoke complex conjugate root theorem

#

and do long division with x^2 + 16instead

cursive knoll
#

got it

elder harbor
#

@cursive knoll

#

sorry

#

x^2 + 16

amber waspBOT
#

@cursive knoll Has your question been resolved?

#
Channel closed

Closed by @cursive knoll

Use .reopen if this was a mistake.

#
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.

split sail
#

Someone know why with scalar product in 2D u have (a,b).(c,d) = |(a,b)| *|(b,c)|*cos(g) with g the angle between the 2 vectors

split sail
#

the thing with | is the norm

mint nacelle
grizzled pagodaBOT
#

higher's secret twin brother

split sail
#

yes but why is it also equal to ac+bd ?

mint nacelle
#

using these axioms

#

yeah I think that's what you're looking for

#

it's more natural to conclude |v| |w| cos theta than to start from that and work your way backwards, you're right

split sail
#

ok i see thank you

amber waspBOT
#

@split sail Has your question been resolved?

amber waspBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

#
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.

vale garnet
#

I don't understand why the dimensions of acceleration should be LT^-2 instead of LT^-1
look at my steps

rancid raven
vale garnet
#

but

#

there is an extra time in the equation here

#

a(t)

rancid raven
#

Where is extra t

vale garnet
#

oh

rancid raven
#

🤔

vale garnet
#

well I didn't understand that

#

thanks

rancid raven
vale garnet
#

yeah a times t

rancid raven
#

No no

#

That's acceleration function

vale garnet
#

hmm okay so if it's a function I don't count it

rancid raven
#

Like f(x) is function in terms of x not f multiply by x

vale garnet
#

alright gotcha

#

.close

amber waspBOT
#
Channel closed

Closed by @vale garnet

Use .reopen if this was a mistake.

amber waspBOT
#
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.

tawny harbor
amber waspBOT
tawny harbor
#

how are they able to apply limit comparison/comparison test here>

#

I thought it can only be used for sequences, and not seuqneces of functions?

#

i.e., must be discrete

#

so shouldn't something like the weierstrass m-test be used instead?

cunning birch
#

isn't u_n = sin(1/n^2) a sequence?

#

that we compared with v_n = 1/n^2

hearty inlet
amber waspBOT
#

@tawny harbor Has your question been resolved?

amber waspBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

#
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.

primal holly
#

If $x, y \in \set R$ are chosen independently following a standard normal distribution, what is the expected distance of the point $(x, y)$ from $(0, 0)$?

grizzled pagodaBOT
#

krypton

primal holly
#

I just want someone to check my pdf

#

[ X^2 + Y^2 = D^2 \sim \chi^2 ]

grizzled pagodaBOT
#

krypton

primal holly
#

nvm

#

.close

amber waspBOT
#
Channel closed

Closed by @primal holly

Use .reopen if this was a mistake.

edgy vector
#

correct @primal holly

amber waspBOT
#
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.

sudden arch
amber waspBOT
sudden arch
#

Is question 2 correct?

solemn escarp
#

yep

tulip tapir
#

no...

spiral zealot
#

no

sudden arch
#

Cause I asked someone else and they got - 5/2

tulip tapir
#

;-;

solemn escarp
#

oh y is incorrect

molten shale
#

nope

sudden arch
#

Where did I go wrong

#

Nope I got it

solemn escarp
spiral zealot
#

your work is too cropped to see

sudden arch
#

1 + 4y = -9

#

4 y = -10

#

Y = -2.5

#

Or - 5/2

#

I messed up and put 4 y = -8

#

Ok thanks

#

.close

amber waspBOT
#
Channel closed

Closed by @sudden arch

Use .reopen if this was a mistake.

amber waspBOT
#
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.

slim epoch
#

[this is the Cauchy-Binet formula] i'm having trouble understanding over what the sum is taken, is it the same as summing over all subsets of {1, ..., n} that contain m elements? and then ordering them j1 as the smallest up to jm?

indigo cloud
#

yes

slim epoch
#

perfect thank you! catlove

#

.close

amber waspBOT
#
Channel closed

Closed by @slim epoch

Use .reopen if this was a mistake.

amber waspBOT
#
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.

hard frost
amber waspBOT
#

Please don't occupy multiple help channels.

hard frost
#

i dont get part c why is it when x(t) = -1

#

and not 1

spiral zealot
#

how are you getting 1

hard frost
#

uhh lemme show u

#

-1 x -3 = 3

#

and they add up to 4

#

-4

spiral zealot
#

those are the values of time that they got

hard frost
#

oh

spiral zealot
#

you're not done yet

hard frost
#

do i need to sub it in

#

ohh

#

i need to sub it into displacement

#

okok thx

#

.close

amber waspBOT
#
Channel closed

Closed by @hard frost

Use .reopen if this was a mistake.

amber waspBOT
#
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.

hoary quail
#

I am not sure on how to do this

amber waspBOT
hoary quail
#

And what laws to use

#

T = 2 h = 7,200 s

#

It's a circular orbit

#

So r is constant

#

But Idk what formulas to use to prove that mass is irrelevant

split sail
#

do u know the formula for a speed in polar coordinates ?

hoary quail
#

I don't think so

#

But why specificaly polar?

split sail
#

bc it is appropriate for this problem

naive pivot
hoary quail
#

So

#

Is this the gravitational force formula?

naive pivot
#

no this is the speed

#

The formula I meant is
F=GmM/r^2

hoary quail
#

Okay

maiden stratus
#

not speed?

hoary quail
hoary quail
split sail
#

bc the sattelite is turning around

#

but what are u allowed to use ?

naive pivot
# hoary quail

The only force applying to the satellite is the gravitational force
So the net force=gravitational force

hoary quail
split sail
#

it says a stable circular orbit

hoary quail
#

Yeah

split sail
#

i think it means that the sattellite is moving at constant speed and in circle

hoary quail
#

It's orbiting around the earth

#

It doesn't mention if the sattelite is rotating

split sail
#

uh if it wasnt it would fall...

hoary quail
#

What

#

No

split sail
hoary quail
#

Wait we're talking about the same thing

#

My bad

#

I thought you meant the sattelite was rotating around its own axis

split sail
#

ok i see

#

so what are u allowed to use ?

hoary quail
#

But yeah, it's orbiting around the earth in 2 hours

hoary quail
split sail
#

about formulas

hoary quail
#

They didn't spesify

naive pivot
split sail
#

what about a=v^2/r

hoary quail
#

Is a area?

naive pivot
split sail
#

a is accelerzation

hoary quail
#

Oh obviously

naive pivot
#

F=ma would also help

hoary quail
#

I'll try the F=ma since I have an idea of what to do there

split sail
#

actually u cant use a = v^2/r

naive pivot
split sail
#

bc u suppose that r is constant, but u also want to prove that it is constant

#

or

hoary quail
#

Can I cross out the small mass?

naive pivot
split sail
#

or i didnt well understand and u know that it is constant but u only want to prove that it is independant ?

hoary quail
#

Still going alright?

split sail
#

v/t ?

naive pivot
hoary quail
split sail
#

t is time ?

hoary quail
hoary quail
split sail
#

no

hoary quail
#

Wdym

split sail
#

a = dv/dt

hoary quail
#

Acceleration is the change in velocity over time

naive pivot
split sail
#

yes, still true tho

hoary quail
#

But v and t don't change

#

Since it's circular

split sail
#

u want to prove it

hoary quail
#

Orbit is 7200s

#

so r is const

#

v is const

#

a can't change

#

And is always 0 m/s² in this scenario

split sail
#

ah no

#

a= GM/r^2

hoary quail
split sail
#

having an acceleration doesnt alway mean that ur speed change

naive pivot
split sail
#

and radius

hoary quail
hoary quail
split sail
#

yes

hoary quail
#

So
a = G • M/r²
Doesn't turn into
a = v²/r
?

split sail
#

wdym ?

hoary quail
split sail
#

idk what ur asking

hoary quail
#

I am trying to prove that mass is irrelevant

#

To v and r

split sail
naive pivot
hoary quail
#

Which one?

naive pivot
#

sorry meant m/s^2
(m/s)^2/m=m/s^2

hoary quail
#

Yeah

#

No worries

naive pivot
#

but you should rewrite a as v^2/r and solve for v and you proved that velocity is independent from mass

split sail
naive pivot
naive pivot
hoary quail
#

Is this right?

split sail
#

yes

hoary quail
#

Or m is gone

#

So I guess that is when

naive pivot
#

m referring to the mass of the satellite

hoary quail
#

Yup

#

And M is Earth

naive pivot
#

Yep

split sail
#

hm but we still have no equation that give r as smthg independant of m

hoary quail
#

But m is gone

naive pivot
split sail
#

for v its ok

hoary quail
#

See

naive pivot
#

v=sqrt(GM/r) just solve for r

hoary quail
#

Didn't need m

hoary quail
split sail
hoary quail
naive pivot
hoary quail
#

But r and v don't need to be independent from each other

#

r and v need to be independant from m

split sail
#

by using the same equation to prove 2 different stuff, u assume that r is independant in first to show that v was independant, and then u did the opposite so it is wrong

hoary quail
naive pivot
hoary quail
#

Since we were able to remove m

split sail
#

but u cant assume smthg u want to prove

hoary quail
#

But we proved it

#

Since we removed m

split sail
#

with v= sqrt(GM/r) , u didnt prove that v is independant of m because r could depend on m still

hoary quail
#

How

#

r is there, m is not

split sail
#

cause it'll be smthg like v(m) = sqrt ( GM/ r(m) )

naive pivot
hoary quail
#

Everything that's still there is independant from m

#

Because we removed m

naive pivot
naive pivot
split sail
#

no, it is like if u write a=x so a is independant of t

#

but u didnt veerified if x= x(t)

hoary quail
#

What

naive pivot
split sail
naive pivot
split sail
#

and maybe v and r , u didnt know that before

naive pivot
split sail
#

but u cant tell that r is constant while u didnt prove it

naive pivot
#

doesn’t even depend on any variable to begin with

split sail
#

idk how to tell

#

anyway that is probably enough, its just quibbling , but rigorusly u need an other equation

naive pivot
#

another equation is not needed

split sail
#

v depend on r and not on m ok

#

u get that with sqrt(GM/r)

#

but u need smthg else to tell that r is not r(m)

naive pivot
split sail
#

yes

#

a lengh can depend on a mass in other cases

naive pivot
split sail
#

in other cases yes

naive pivot
#

Like what ?

split sail
#

the lengh of a spring

naive pivot
hoary quail
#

Why would r from Earth to sattelite depend on m to sattelite?

split sail
naive pivot
hoary quail
#

Why are we talking about springs?

split sail
naive pivot
split sail
naive pivot
hoary quail
#

Isn't that F = -kx?

split sail
#

yes

naive pivot
hoary quail
#

So

split sail
#

but still depend on the mass

hoary quail
#

Not mass

#

But force

split sail
naive pivot
split sail
#

so yes mass

hoary quail
#

And length stretched/compressed

naive pivot
#

not the mass of the satellite

split sail
#

it isnt the same

hoary quail
#

Well thanks for the help anyways

#

I need to continue with the assesment

#

Y'all can continue in dm's so thia channel is open to someone that needs help

split sail
#

k

hoary quail
#

.close

amber waspBOT
#
Channel closed

Closed by @hoary quail

Use .reopen if this was a mistake.

amber waspBOT
#
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.

sharp dock
#

<@&286206848099549185>

amber waspBOT
sharp dock
#

How would I do this?

inland pulsar
#

you forgot to ask the question

#

lmao

sharp dock
#

e

inland pulsar
#

take log

sharp dock
#

Solve each exponential equation for x.

inland pulsar
#

log base 2

sharp dock
#

why base 2?

inland pulsar
#

we know log 8 base 2 and log 4 base 2

#

only need to find log 73

sharp dock
#

What r u talking about

inland pulsar
#

log2(8) = 3

#

log2(4) = 2

#

log2(73) = idk find it yourself

sharp dock
#

Oh

#

One sec

#

Idk how to find it myself

#

That's why I'm here for

inland pulsar
#

are you allowed calc?

sharp dock
#

yes

#

But let's say I'm not

inland pulsar
#

use that

#

i dont think you can without calc

sharp dock
#

Ok how would I use my fucking calculator

#

I'm about to break everything here

#

Fuck my teacher

#

SOMEONE HELP ME

#

HOLY

pallid canopy
#

Chill

shell barn
#

do you know how logarithms work?

sharp dock
#

no

#

Barely

inland pulsar
#

damn

sharp dock
#

And I got a quiz on this tmrw

#

My teacher can't teach for shit

#

Man teaches us the easiest questions then gives us the hard one

shell barn
#

,tex log rules

#

,tex .log rules

grizzled pagodaBOT
#

NatTaylorsV

alpine flower
#

so

#

8 = 2^3

sharp dock
#

Yes

alpine flower
#

write it as 2 * 4 * 4^(2x-3)

sharp dock
#

Ok

#

But why do we still have the 2x at the top?

alpine flower
#

4*4^(2x-3) = 4^(2x-3+1) = 4^(2x-2)

sharp dock
#

When we used it for 4x4

sharp dock
alpine flower
#

ye

#

2* 4^(2x-2) = 73

sharp dock
#

One sec

#

I just got even more confused

#

Where tf did the 1 come from

sharp dock
#

3+1??

alpine flower
#

4^(x) *4 = 4^(x+1)

elder creek
#

why do all this

#

he has a calc'

sharp dock
#

Honestly im so lost

#

This just made me even more confused

alpine flower
#

cuz we have to solve for x

sharp dock
#

The teacher said the final answer should be 2.30

elder creek
#

yes you can solve it for it any easier manner

#

...

sharp dock
#

But how tf do we get 2.30

sharp dock
#

I'm erasing all of this

#

Im sorry

elder creek
#

ok start with this

sharp dock
#

But this takes too much time to do on a quiz

elder creek
#

how do we start by isolating x's

sharp dock
#

Alr

elder creek
#

alaska, your way works, but its hard for someone who is learning logs/exponetials to follow

alpine flower
#

i know

#

i was simplifying so that I could apply log_4

elder creek
#

you can apply log 4 in the second step either way

#

@sharp dock

#

how do we start

#

what is the easiest step here

#

should be a 73 oops

sharp dock
#

Ok one sec

sharp dock
elder creek
#

how can we get 8 and in 4 in terms of the same power

sharp dock
#

I'm not sure

elder creek
#

how exponet on 2

#

gives us 8

#

and what exponet on 2

#

gives us 4

sharp dock
#

2

elder creek
#

3 and 2

#

y did u delete

#

3

sharp dock
#

Mb

#

But yea 3 and 2

elder creek
#

so we have this

#

simply a little more

sharp dock
#

Simplify more?

#

Idk tbh

#

Subsract the 2x-3

elder creek
#

this right

#

distrbute the 2

#

now

#

look at product

#

when we have two bases mutiplied, we add their exponets

#

how do we simply left side

sharp dock
#

What left side

#

Ima look at the product rule rq

elder creek
sharp dock
#

Yep

#

I got that part

#

Now what?

elder creek
#

did u simplify

sharp dock
elder creek
#

yes

sharp dock
#

no

#

Do we multiply the 2s now?

elder creek
#

yes

sharp dock
#

4^3^(4x-6)

elder creek
#

no

#

add the exponets

sharp dock
#

Oh

elder creek
#

remember

#

when same base mutiplied add exponet

sharp dock
#

So instead of 2x2 being 4

#

Why did u put 2?

elder creek
#

remember

#

2^2=4

sharp dock
#

yea

#

But 2x2 is also 4

elder creek
#

coincidence

#

not really a coincidence but

#

you want to use exponets

sharp dock
#

Huh 😭

elder creek
#

2x2=2^2

#

but using 2x2 format here doesnt help us

sharp dock
#

Okok

#

So what format do I use?

elder creek
#

2^2

sharp dock
#

If they were different numbers

elder creek
sharp dock
#

So instead of multiplying them

#

I just do 2^2

#

Or 5^6

elder creek
#

mutiplying is just exponets

sharp dock
#

Or wtv the number is

elder creek
#

5^6=5x5x5x5x5x5

#

just write in exponet format

#

when solving these equations

#

remember

#

we made the oringal expression into this

sharp dock
#

Yea

#

Alr

elder creek
#

when turns into this

#

now just add the exponets

#

together

#

bc they have the same bases

sharp dock
#

It's 1

elder creek
#

3+(4x-6)=1?

sharp dock
#

Yea

#

That's what my calculator says

elder creek
#

....

#

if you plug x into your calc

#

that doesnt mean anything

#

to it

#

it will spit out 1 just bc it doesnt know what to do

#

there is infintely many values x could be

#

you have to define x for it actually do something

#

but you are solving for x

sharp dock
elder creek
#

so you dont even know x

sharp dock
#

Or is it supposed to be -21?

elder creek
#

you did

#

3+(4-6)

#

not

#

3+(4x-6)

#

you just dropped the x

sharp dock
#

So 4 x (-6)

#
  • 3
#

That's -21

elder creek
#

4x-6

#

+3

#

whats -6+3

#

no calc

sharp dock
#

-3

#

My wifi is so bad

elder creek
#

yes

#

so we have this now right

sharp dock
#

My messages are lagging

#

Yes

elder creek
#

now

#

what do we do

#

hint logs

sharp dock
#

Logbase2,73= 4x-3

elder creek
#

ye

#

now its just a simple alegbra equation

sharp dock
#

How

elder creek
#

add 3 to the other side

sharp dock
#

Why

elder creek
#

uh

#

bc we are solving for x

#

so isolate x

sharp dock
#

Okok

#

Then let's take the 4 off as well

#

If we want x alone

elder creek
#

yes

sharp dock
#

WTF

elder creek
#

so now plug that into ur calc

#

?

#

all i did was divide everything by 4

sharp dock
#

Okok

#

Idk how to put logbase2, 73 in my calc

#

It ain't a scientific one

elder creek
#

lmfao

#

basiclaly enter

#

in leui

sharp dock
#

What's leui

sharp dock
elder creek
elder creek
#

like replacement of

sharp dock
#

1.547

elder creek
#

+3/4

sharp dock
#

0.75

elder creek
#

1.547+.75

sharp dock
#

So now

#

We put 1.547 over 0.75

#

Right?

elder creek
#

no

#

plus

sharp dock
#

Oh ok