#help-28

1 messages · Page 154 of 1

sinful wasp
#

so i would do the equation and whatever i got for m1 will be the same as m13?

hard veldt
#

yea

sinful wasp
#

alr

#

i got 40

#

how do i start this?

#

?

hard veldt
#

What is the measure of $\angle ADC$?

glossy valveBOT
#

Dork9399

sinful wasp
#

128?

#

ohhh

#

wait

#

is the answer 52?

#

like

hard veldt
#

yea

sinful wasp
#

alr

#

how would i start

hard veldt
#

what is the measure of $\angle ABC$?

glossy valveBOT
#

Dork9399

sinful wasp
#

57

hard veldt
#

What is the measure of CBD?

sinful wasp
#

123

hard veldt
#

CBD, not CBE

sinful wasp
#

uh

hard veldt
#

its an isosceles triangle with a vertex angle of 90

#

what does the make the other two angles?

sinful wasp
#

im not sure

hard veldt
#

The angles of the triangle are 90, x, and x. What does that make x?

sinful wasp
#

45?

hard veldt
#

yes

sinful wasp
#

so b=45?

hard veldt
#

So ABC = 57, CBD = 45. What does that make EBD?

sinful wasp
#

78

hard veldt
#

So what is BDE?

sinful wasp
#

12?

hard veldt
#

yay!

sinful wasp
#

thats all

#

.close

full forumBOT
#
Channel closed

Closed by @sinful wasp

Use .reopen if this was a mistake.

sinful wasp
#

ty

#

.close

full forumBOT
#
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.

charred geode
#

can I cancel differentials ?
for example: if dx/dt = dy/dt does that mean that dy=dx?

muted summit
#

uhhh... kinda
whats the context

muted summit
#

because, dy/dx is its own thing,

But you can do that trick when doing integrals

sacred sparrow
full forumBOT
#

@charred geode Has your question been resolved?

full forumBOT
#
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.

proven spade
#

hello

full forumBOT
proven spade
#

i need some urgent help!

gritty rose
#

!15m

full forumBOT
#

Please only use the <@&286206848099549185> ping once if your question has not been answered for 15 minutes. Please do not ping or DM individual users about your question.

arctic void
proven spade
arctic void
#

💀

proven spade
proven spade
arctic void
proven spade
arctic void
#

Pls share what u have tried

proven spade
arctic void
proven spade
#

i just did a whole page of other work

#

i dont need to show you what I completed your not even a helper

#

<@&286206848099549185> its been 15 mins

devout dawn
#

Who need help?

proven spade
#

i do

#

some guy interjected into my question

#

he was really rude

#

he was juding me for not understand a question

devout dawn
#

I am very sorry for him, if we understand everything it is impossible to learn

#

So what is your question?

pale otter
#

kirito is a helper.

but for the question, if enlargement makes an image bigger, and reduction makes it smaller, then how do you think the small triangle b in question one must be scaled to make the big triangle A?

proven spade
proven spade
proven spade
proven spade
pale otter
#

good, you got it

proven spade
#

so basiclly englargment is bigger and smaller is reduction

pale otter
#

yeah

arctic void
#

Nice✅

devout dawn
#

That is

arctic void
#

But u didn't share yr 2 page working

proven spade
#

okay and I have one more question

arctic void
pale otter
#

yeah

pale otter
proven spade
#

its asking to find the scale factor out of these two

#

but im not sure how to find it

#

is it the bigger one?

devout dawn
#

To find the scaling factor, divide the lengths of the corresponding sides

proven spade
#

so divide every single side?

#

so like 40/20 and 8/6?

devout dawn
#

For example in the figure on the right, the scaling factor is 2

#

The corresponding sides of the two similar figures

proven spade
#

for each?

devout dawn
#

The larger figure is obtained by multiplying each side of the smaller figure by 2.

#

8/4=2

#

6/3=2

proven spade
#

where do you get the 4 from

#

but its asking me find the scale factor

#

out of the 2

devout dawn
#

The scaling factor is the number by which you multiply the sides of one figure to obtain the other

pale otter
#

you see how the figures are congruent? (they look the same, with the same ratios between side lengths)

#

I think factoring could help:
try factoring the side lengths on each figure ans see what factors match up

proven spade
#

so would it be the 2nd one?

devout dawn
#

48/40

devout dawn
#

8/4 On the right side

proven spade
#

sso would the correct on be on the left?

full forumBOT
#

@proven spade Has your question been resolved?

keen mango
#

It looks like the question is asking for a number, not for you to choose a shape

full forumBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

full forumBOT
#
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.

twin wolf
#

So I graphed f(x) in desmos and the sign testing holds up when I check the sign from (1, inf) it’s always increasing and from (-inf,-1) it’s always decreasing.

But what if I have a function that changes concavity somewhere towards -inf and + inf? Will the sign testing still hold up

gritty rose
#

What question are you using the sign test for

twin wolf
#

well i dont have to use it here but i just wanted to try and see if i could curve sketch it

all i had to do was find the max or min points and find the stationary point

#

im just curious if i was to use the sign test to curve sketch

#

would the sign test catch whether there would be a change in concavity in a later interval

like for example i know that this function will always be concave up from (1,inf) but what if it changed somewhere during that interval ( ik it doesnt but just asking)

full forumBOT
#

@twin wolf Has your question been resolved?

twin wolf
#

.close

full forumBOT
#
Channel closed

Closed by @twin wolf

Use .reopen if this was a mistake.

full forumBOT
#
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.

vapid spindle
#

Find the smallest possible integer n, such thar n! is divisble by 2⁵×3⁵×5⁷

Is the answer 35 correct?
My reasoning was since we need 2, 3 five times in the factorial and 5 seven times we can go with five and find the number with five seven times.

Or is 30 the answer?
Since there's two fives in 25?

full forumBOT
#

@vapid spindle Has your question been resolved?

sacred yarrow
#

It’s excessive

full forumBOT
#
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.

raven mauve
#

hi

full forumBOT
raven mauve
#

can someone see if i am correct please?

raven cloud
#

if the 2 after square root of 5 is a power yes ur correct

raven mauve
#

oh shoot my bad i didnt see

#

i thought it was a power

#

so in that case

#

its just 2 square root 5?

raven cloud
#

its weird how its behind the square root lol why would not they just write 2*(square root of 5)

#

im guessing its a power

raven mauve
#

ye possibly a mistake

#

is this correct

#

wait oops

raven cloud
#

u gotta show that 45 is equal to that not that 3 square root of 5 is equal to that

#

square root of 45= square root of 9 times by square root of 5

#

then square root of 9 is 3

#

and its 3 times square root of 5

raven mauve
#

sorry like this?

raven cloud
#

ya

raven mauve
#

i messed up my bad

#

i keep making small mistakes

raven mauve
#

u just have to prove it?

raven cloud
#

yea

#

got anything else? im bored cause no one answered my questions in the help channel

#

i could help

raven mauve
#

this one is the last one

raven cloud
#

gonna be

#

sqrt(x)=8

raven mauve
#

just 8?

raven cloud
#

then square both sides

raven mauve
#

wait what

raven cloud
#

basically

#

if u devide both sides by 2

#

nothing changes

#

but it becomes more simple

#

easier to solve

raven mauve
#

so final answer is 8?

raven cloud
#

no

#

u gotta find x

vernal gale
raven cloud
#

not sqrt(x)

vernal gale
#

pythagoras

raven cloud
raven mauve
vernal gale
#

ok

raven mauve
#

so x = 8

#

pretty much?

raven cloud
#

no

#

when u devide both sides by 2

#

what do u get

#

?

raven mauve
#

sorry im confused

#

as hell

#

what do u mean divided by both side

#

this?

raven cloud
#

yes

#

then

#

u gotta find x

raven mauve
#

so then u do 8-1?

#

waist no

#

wait

#

ye im confused

opal isle
#

10 = 7 + 3 <==> x7 both sides is 7(10) = 7(7+3)

#

2sqrtx = 16

#

÷2 both sides

#

sqrtx = 8

raven cloud
#

if u wanan get x from sqrt(x)

#

u gotta square it

#

x=8^2

#

x=64

raven mauve
#

huh

#

wait i think i got it

#

OHHH wait ye i got it

#

ty guys

#

.close

full forumBOT
#
Channel closed

Closed by @raven mauve

Use .reopen if this was a mistake.

full forumBOT
#
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 bluff
#

hey can someone help me with a.

full forumBOT
hoary bluff
#

im confused what its asking me to do

hot herald
#

long division

hoary bluff
#

yes but

#

like

#

what divided by what

#

well i know

#

but

#

if i do will it turn into the form a/x-1

raven cloud
#

do u know how to devide that thing by x-1?

hot herald
#

yeh, do the division

hoary bluff
#

yeah

raven cloud
#

do it

hoary bluff
#

okay ill do it and come back

#

brb

hoary bluff
raven cloud
#

thats it

hoary bluff
#

huh

raven cloud
#

x^2+3x+8 is P(x)

hoary bluff
#

oh

raven cloud
#

and a is 9

hoary bluff
#

so its just weird wording for solving long division

#

uurrrgghh

#

thank u tho

#

haha

#

.close

full forumBOT
#
Channel closed

Closed by @hoary bluff

Use .reopen if this was a mistake.

full forumBOT
#
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.

vast rover
#

Could I get some help with question 1 please? I have done the base case but how do I make use of the orbit stabiliser theorem (or its corollary) in the inductive step?

full forumBOT
#

@vast rover Has your question been resolved?

full forumBOT
#

@vast rover Has your question been resolved?

full forumBOT
#

@vast rover Has your question been resolved?

full forumBOT
#

@vast rover Has your question been resolved?

full forumBOT
#

@vast rover Has your question been resolved?

#
Channel closed

Closed by @vast rover

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.

desert musk
#

"Assume that f is uniformly continuous on (-∞, 0]. Also, assume that f is uniformly continuous on [0, ∞). Show that f is uniformly continuous on the entire ℝ."

desert musk
#

how do i show this

sacred sparrow
#

to show that f is continuous at 0.

manic token
#

try to start from f(0)

sacred sparrow
#

then f is continuous on all R

desert musk
#

yeah, i suppose i only need to show it is on f(0)

sacred sparrow
desert musk
#

where both x and y are 0

#

or only one of them

manic token
#

x=0

desert musk
#

what about y

manic token
#

y=y

#

🙂

#

it doesnt matter

sacred sparrow
quaint prawn
#

Take the minimum of the two deltas you are guaranteed

#

And rejoice

desert musk
#

what exactly is the y then

sacred sparrow
#

you don't know? y = f(0)

desert musk
#

i thought we had x and y because of mutiple dimensions

manic token
#

it doesnt matter and you dont know it

quaint prawn
#

It doesn’t matter and you don’t know it

#

Just feel like it should be said again

manic token
#

yeah lol

manic token
#

lim x=0+ ,f(x)=f(0)

#

lim x=0- ,f(x)=f(0)

#

em

quaint prawn
#

There’s no need for limits either

manic token
#

sorry

#

im not doing well

sacred sparrow
# manic token im not doing well

nw, help is always appreciated. The left/right side limit approach would work if it were continuity instead of uniform continuity :)

#

@desert musk what have you written so far?

quaint prawn
desert musk
quaint prawn
#

Now apply the same definition on the other side of the interval

quaint prawn
manic token
desert musk
#

i just never really feel done when i do epislon thing

#

you just write down the defintion and say now its proven

sacred sparrow
#

mind showing what you have?

#

I'd split it into:
Let x,y e R. we want to show that
|x-y|<delta ===> |f(x)-f(y)|<eps

desert musk
#

yes

sacred sparrow
#

if x,y both in the first interval, then it's true since delta ≤ delta1

desert musk
#

but i never feel like nice i got it when i do these sort of questions

#

you just write down the defintion and say "now it holds"

sacred sparrow
#

and x,y both in the second interval then it's true since delta ≤ delta2

sacred sparrow
desert musk
#

see im never really sure if i have

#

i dont have a picture in my head of what im doign when i do this

sacred sparrow
#

k a sec I'll switch to pc

#

here we know that f is uniformly continuous for all R\{0}

#

now if we let x to be in the first interval and y to be in the second, we'll need to show the same

desert musk
#

it is correct x and y just a points

#

that are some distance away from each other less than epislon

#

just like in the normal continuity but than y is instead of a?

quaint prawn
#

This is not correct

#

You have the quantifies backwards

sacred sparrow
#

oops I switched delta epsi

quaint prawn
#

That’s not the only issue

#

We have uniform continuity

#

There’s still an issue

#

there exists delta, such that for all x, y

#

Not the other way around

sacred sparrow
#

what am I doing lol

desert musk
#

can you draw me a visual graph of it

quaint prawn
#

We don’t know what f is

#

So no

desert musk
#

ill rephrase

#

an abitrary graph

sacred sparrow
quaint prawn
#

I don’t think it’d be useful here

quaint prawn
#

If. |x-y| < that then what can you say?

#

Was telling them

desert musk
#

i tried nevertheless

sacred sparrow
# desert musk

yea the eps-delta rectangle is what you can visually infer

desert musk
#

then draw from x and y

#

up to the points on the graph

#

i think for my graph it doesnt even hold

#

but still

#

why are we letting it be the minimum of delta

#

?

desert musk
sacred sparrow
#

x in the first interval and y in the second

desert musk
#

then i wont learn

quaint prawn
desert musk
#

i need to be able to guess the answer myself

quaint prawn
#

Say one delta is 2

desert musk
#

what is the rational behind it

quaint prawn
#

And one delta is 5

#

If we say, let our big delta be < 2

sacred sparrow
quaint prawn
#

Then we know we get both conditions

desert musk
#

big doesnt imply being the biggest?

sacred sparrow
#

I can also add it into the first two trivial cases iyw

desert musk
#

so you just the smallest delta of your two deltas

#

which ever one that is

#

so we write delta = min(delta1,delta2) now i am sure that i've picked the smallest delta. Why is that important?

quaint prawn
#

This is going nowhere

#

We need to clean up our ideas and work

desert musk
quaint prawn
#

Mav

desert musk
#

if you can answer questions

quaint prawn
#

You are trying to show uniform continuity on (-inf, inf)

#

Write out what you must prove

desert musk
#

i just need to show it for f(0)

#

the rest has already been given

quaint prawn
#

That’s not important

desert musk
#

but im still asking you it is important to pick the smallest delta

quaint prawn
#

Yes it is important

desert musk
#

and now why?

quaint prawn
desert musk
#

that f is uniformly continous at x =0

quaint prawn
#

No

desert musk
#

how is that not it

quaint prawn
#

And that’s doesn’t have any quantifiers

#

I want you to write out formally

#

What it means for f to be uniformly continuous on (-inf, inf)

#

As that is what we are trying to prove

desert musk
#

For a function f to be uniformly continuous on (-∞, ∞), it means that for any ε > 0, there exists a δ > 0 such that for all x, y in (-∞, ∞), if |x - y| < δ, then |f(x) - f(y)| < ε, regardless of how large or small x and y are

quaint prawn
#

Yes and the last part doesn’t need to be included

quaint prawn
#

So then you can consider cases of x,y

desert musk
#

why is that true

quaint prawn
#

What

#

if x < min (5,7)
x < 5
And
x < 7

desert musk
#

why

#

it just says x < 5

quaint prawn
#

?

desert musk
#

5 is min of 5 and 7

quaint prawn
#

yeah and if x<5

#

It’s certainly less than 7??

#

Since 5<7

desert musk
#

oh nvm

#

well ok

#

so now we are saying that it is smaller than the smallest delta then it is smaller than all deltas?

quaint prawn
#

Smaller than the 2 that we are given yes

#

So consider an arbitrary |x-y| with x, y in (-inf , inf)

#

If |x-y| is less than our minimum chosen delta

#

Well if x, and y are in the same interval then we’re already done

#

Because we’re given uniform continuity in each

#

So only considering now WLOG x<0<y which I think was written above

desert musk
#

WLOG?

quaint prawn
#

Without loss of generality

desert musk
#

what does that mean

quaint prawn
#

It doesn’t matter if it’s y < 0 < x

#

Or x < 0 < y

#

Basically since the variables don’t matter here

#

We can only consider one case as they are the same

#

So without loss of generality means we can ignore the other case, it’s the same

desert musk
#

so

#

if 3 fruits either apple or banana at least two of them will be the same

#

and it doesnt matter if i take the case of the banana or apple

#

an example for WLOG @sacred sparrow

sacred sparrow
#

just wondering why you said 3 fruits

quaint prawn
#

Well if the qualities of them being an apple or banana don’t matter

#

Sure

sacred sparrow
#

you just want to express that x,y e R but x and y are in the different intervals

desert musk
#

WLOG just means that it could have been y < 0 < x

#

right?

quaint prawn
#

Yes

#

It’s like saying, given two distinct numbers a and b

#

We can say WLOG that a<b

#

Right because otherwise b<a

#

And we can just relabel

desert musk
#

alright

sacred sparrow
desert musk
#

arh

#

smart triangle inequality

sacred sparrow
#

ys you almost always use estimates

#

to show |f(x)-f(y)|<eps

desert musk
#

idk it just feels weird doing these sort of things

sacred sparrow
#

yeah it may feel overly strict and formal at first

desert musk
#

im just giving myself what i need to solve it by for exmaple saying less than episolon/2

sacred sparrow
#

only once you accept the freezing you'll start liking the cold water :3

desert musk
#

feels like solving a physics problem and just given yourself the information you need

sacred sparrow
#

you do these steps in reverse

#

above I first used the triangle inequality

#

to see that I need eps/2

#

I didn't know it beforehand

#

(well I partially did, but let's assume I didn't)

#

often you first rearrange |f(x)-f(y)| to find out what estimates you actually need

desert musk
#

and we knew that |f(x)-f(0)| is less than epislon epsilon/2

#

because we said it was for any x and y

#

which also includes y = 0?

sacred sparrow
#

in (-inf, 0]

#

x and 0 are in that interval

#

that's why I chose f(0)

#

because 0 is in both intervals

desert musk
#

yes, but the idea its that it has to be smaller for all x and y in the interval

#

which will also be 0

#

smaller than epislon/2 that is

sacred sparrow
#

ys

full forumBOT
#

@desert musk Has your question been resolved?

full forumBOT
#
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.

misty lynx
full forumBOT
cursive nacelle
#

Is this a quiz

marsh summit
#

!status

full forumBOT
#
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
misty lynx
#

no its hw

#

but i just got it

#

thanks tho

#

.close

full forumBOT
#
Channel closed

Closed by @misty lynx

Use .reopen if this was a mistake.

full forumBOT
#
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.

royal pawn
full forumBOT
royal pawn
#

Not really sure how to do this. Any suggestions?

full forumBOT
#

@royal pawn Has your question been resolved?

full forumBOT
#

@royal pawn Has your question been resolved?

full forumBOT
#

@royal pawn Has your question been resolved?

full forumBOT
#
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.

nimble crane
#

small confusions i had when revisiting this proof:

  1. why is the sum going to be direct?
  2. what does it mean when it says "by uniqueness on 0 \in V"?
full forumBOT
#

@nimble crane Has your question been resolved?

wide star
#

bad wording

#

Any vector in a direct sum can be written uniquely as a sum of vectors

#

Each term of the sum comes from one of the spaces in ur direct sum

#

(Up to order)

nimble crane
#

hm okay, why does that imply that T(xi) = 0?

wide star
#

Tx=0

#

Now expand x out using the direct sum decomp

nimble crane
#

ah

wide star
#

T-invariance tells u each term is in the cortesponding space from the direct sum

#

By uniqueness since Tx=0 each term in the sum for Tx ends up being 0

nimble crane
#

got it

#

now for Q1...

#

why is the intersection of all those kernels going to be 0?

wide star
#

There's several ways to pose being a direct sum so perhaps there is a better way to think about it?

#

Maybe I am misunderstanding. I'm still trying to think that out myself tbh

nimble crane
#

hmm

wide star
#

I know from friedbergs linalg book that V=R(T)+N(T) implies V=R(T) oplus N(T). It is an exercise there at least.

#

Your direct sum is really a sum of restrictions of T to subspaces so maybe chaining some silly facts like that together might work.

wide star
#

This was also an exercise from friedberg.

wide star
#

Could the null space of say T restricted to V_1 be in V_1 by T-invariance maybe?

#

Oh I think it's literally just intersection bs

#

V_1 and V_2 already only intersect at 0

#

Further intersections won't change that.

#

Same idea should generalize to the whole direct sum I think

nimble crane
wide star
#

Yah

#

Lemme dbl check iterated direct sum stuff

nimble crane
#

apologies, but that doesnt seem obvious to me

wide star
nimble crane
#

got it

#

that makes sense

wide star
#

It also trivially contains 0 (so is a superset of {0}).

nimble crane
#

ty

#

.close

full forumBOT
#
Channel closed

Closed by @nimble crane

Use .reopen if this was a mistake.

full forumBOT
#
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.

glossy valveBOT
hallow walrus
#

I think you mean $e^{cx}$

glossy valveBOT
#

kheerii

hallow walrus
#

Ah, ok

#

Oh, well y=0 is only a solution when the equation has no independent x terms or constants

#

Why not

#

Yeah, only when there are no independent x terms or constants

#

Just try putting y=0 into any random DE

glossy valveBOT
#

4C
Compile Error! Click the errors reaction for more information.
(You may edit your message to recompile.)

hallow walrus
#

It is, because there are no independent x terms or constants

rare dock
#

what even is the question

#

i read that

hallow walrus
#

As in, each x term(if any) is multiplied to some derivative of y

#

What?

#

y=0 can only be a solution if BOTH of the conditions are true

hallow walrus
#

How…

#

There’s no constant

#

And there’s no independent x term

#

It’s multiplied to the y’ though

#

Something like y’+2y”y+3x=0 for example

#

This can’t have y=0 as a solution

#

Or y”y+3y’+1=0

#

Yeah, which is why I said those two conditions

#

Lmao

#

Not sure how to go about the rest of the question

#

It implies y=0 is a solution, unless y is in the denominator

#

Yeah, and that y or any of its derivatives is not in the denominator

#

Unless im missing something

full forumBOT
#

@torn jolt Has your question been resolved?

full forumBOT
#

@torn jolt Has your question been resolved?

full forumBOT
#
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.

twin wolf
#

I don’t understand what’s going on here

torn jolt
#

sin(x) is the integral of cos(x)

#

it's a substitution

umbral dome
#

so (in a slightly different form) we have
[ \int u v' , dx = uv - \int u' v , dx]
where $u$ and $v$ are both functions of x

glossy valveBOT
umbral dome
#

(which is essentially the power rule in reverse)

#

so then the strategy is to split the integral into a product of two functions, one of which you differentiate, and one of which you integrate, to get a new and simpler integral back

twin wolf
#

So wait

twin wolf
#

Why does dv have to be cosx?

umbral dome
#

because our original integral must have one thing we call "u" and one thing we call "dv"

twin wolf
#

Is dv a function?

#

Or like a derivative operator

umbral dome
# glossy valve **cloud**

i wrote an equivalent definition up here, "dv" is really just [ \odv{v}{x} dx] where $v$ is a function of $x$

glossy valveBOT
rugged void
#

e.g. how if you want to integrate f(x) = say, x^2, you integrate x^2 dx not just x^2

#

it's basically a function times dx, except that the function is a derivative of another function, which we call v

twin wolf
#

Hm.

#

I think the notation is confusing me the most with this

rugged void
#

e.g. if v = sin x, dv would be (dv/dx) times dx = cos x dx

twin wolf
#

if v = sin(x) then dv/dx = sin(x)

rugged void
#

$$v=\sin x$$
$$\frac{\dd v}{\dd x}\dd x=\dd v=\cos\left(x\right)\dd x$$

twin wolf
#

Wait why is dv/dx being multiplied with another dx

rugged void
#

because dv = (dv/dx) * dx

#

the dx's cancel out

glossy valveBOT
twin wolf
#

wait if the dx’s cancel out then why isn’t there still a dx next to cosx?

#

Wouldn’t it just be dv = cosx

rugged void
#

no

#

dv/dx = cos x

#

(dv/dx) * dx = cos (x) *dx = dv

twin wolf
#

then you rearrange to solve for dv and get cos*dx?

rugged void
twin wolf
#

yes

#

This is hurting my brain sad

rugged void
#

look

#

you understand the concept of integrals and derivatives right

twin wolf
#

yes

rugged void
#

the underlying logic behind the formula for a derivative

#

like why the formula is as it is

#

??

twin wolf
#

yes I think so

rugged void
#

okay

#

dx = h, then?

twin wolf
#

What

#

What is h

rugged void
#

one second

glossy valveBOT
rugged void
#

this is the formula for a derivative, correct?

twin wolf
#

yes

rugged void
#

however, this can also be written as df/dx

#

correct?

rugged void
twin wolf
#

Yeah tiny difference in function f over tiny difference in x

rugged void
#

yes

#

so h is the tiny difference in x aka dx right

twin wolf
#

yes

rugged void
#

well

#

then dv = v' times dx

#

and they cancel out

#

bc integration variable

#

and bc it's a LIMIT not bc dx = 0

twin wolf
#

Right..

#

So uh how does this work with the ibp

rugged void
#

lemme show you

#

actually, wait one second

glossy valveBOT
rugged void
#

this is the product rule: (uv)' = u'v+uv'

#

got it?

#

@twin wolf

twin wolf
#

yea

rugged void
#

okay

#

multiplying by dx, we get
$$\dd (uv) = v \cdot \dd u + u \cdot \dd v$$

glossy valveBOT
rugged void
#

okay??

twin wolf
#

I’m just trying to wrap my head around the treating the derivative operator like it’s a normal fraction

rugged void
#

xD

#

i thought that's what we always did lol

#

the "d" here is just to represent infinitesimal change

twin wolf
#

dy/dx = y/x

rugged void
#

no...

#

dy = infinitesimal change in y

#

dx = infinitesimal change in x

#

the "d" represents change
it's not MULTIPLIED

#

think of the d as a function

twin wolf
#

You cancel the d’s

rugged void
#

d(y)/d(x)

#

d(t) = infinitesimal change in t.

#

does that help you understand??

twin wolf
#

ok

rugged void
#

does it

twin wolf
#

i think so

#

Maybe

rugged void
#

okay

rugged void
glossy valveBOT
twin wolf
#

yes

rugged void
#

got it?

glossy valveBOT
twin wolf
#

Why do we want to solve for udv?

rugged void
#

because that's a product

#

like you can't integrate x cos x normally

#

or cot^2 x

twin wolf
#

Isn’t uv the product

rugged void
#

we're trying to integrate u dv... uv is sitting there

#

@twin wolf FOCUS

twin wolf
#

okay

#

I’m just confused like

#

If we want to integrate a product

#

of uv

rugged void
#

no

#

if we want to integrate uv

twin wolf
#

Why integrate only u with respect to dv

rugged void
#

we'll have to do a double integral

rugged void
#

@twin wolf

#

look i don't seem to be able to explain this to you, sorry

full forumBOT
#

@twin wolf Has your question been resolved?

#
Channel closed

Closed by @twin wolf

Use .reopen if this was a mistake.

full forumBOT
#
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.

brittle parcel
#

I'm having trouble understanding this statement "Vectors, colinear with a line, make 1D real linear space"

brittle parcel
#

Ik why they create a real linear space

#

the rest of the statement is "On the line exists a single non-zero vector colinear with the line. All +1 vectors are linearly dependent"

#

and it just says "There, 1D"

full forumBOT
#

@brittle parcel Has your question been resolved?

sacred sparrow
#

why it must be 1D

brittle parcel
#

I'm having trouble fully comprehending this

sacred sparrow
#

ok, consider an arbitrary line in some vector space, R², R³ etc.

#

now which vectors are colinear with that line?

#

well colinear geometrically interpreted is the same as being parallel to it

#

so all vectors that 'go' in the same direction as that line are colinear to it

#

more specifically, if that line goes through the origin

#

then only all the vectors exactly on that line are colinear to the line

#

since they are the only vectors parallel to the line

#

the line could be elsewhere in the space of course

#

but the vectors colinear to it just form the same line, moved to the origin

#

so you can imagine that the set of colinear vectors to a line form a line on their own which is parallel to the other line.

#

and since a line is one-dimensional, that can be considered a 1D real linear space

#

because all vectors within that set

#

fulfill the properties of a linear vector space (addition, multiplication, laws, etc.)

#

@brittle parcel hope that made it visually a bit clearer

brittle parcel
#

I think?

brittle parcel
#

well if they lie on the same line, every line is parallel to itself

sacred sparrow
#

then all vectors parallel to it

#

are the line itself

brittle parcel
#

right

sacred sparrow
#

eg if we were to vis it in 2D:

#

this vector would be colinear to the line

#

this one as well

sacred sparrow
#

or these three

#

now let me draw all vectors colinear to it as points:

#

which is just another line

#

since there are infinitely many vectors colinear to the blue line

brittle parcel
#

I see, I see

sacred sparrow
#

in essence:

#

the red line = the blue line just moved

#

and a line that goes through the origin is a 1D linear vector space

#

you are going to see the same for other objects

#

a plane of vectors that goes through the origin is a 2D linear vector space

full forumBOT
#
Channel closed

Closed by @brittle parcel

Use .reopen if this was a mistake.

full forumBOT
#
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.

clever sand
#

I've got a little problem I'm trying to solve for my own fun which probably has been solved centuries ago but still
what I'm trying to do is make a """"function"""" that takes an actual function "f" and an angle "alpha" and rotate f's graph by alpha radians
first thing I tried to tackle is making a function that takes a point and outputs a point alpha degrees clockwise to that point

I managed to do it without much trouble except for a few parts: when the x of the point xor the y of the point is negative then as you move through the values of alpha the point follows an ellipse instead of a circle, and more importantly: I don't know if it's even possible to make a desmos function that takes a point, let alone another function as its input

this here is what I've done so far

clever sand
#

I don't know if there's much of a better way to solve this, there probably is, but what I did is make a function g that takes a and b, or the x and y of the point, for the x take the arccos of its x/hypthenuse to get the angle, add alpha to it then use cos to reverse it and get the ratio from the wanted x to the hypothenuse, then just multiplied by the hypothenuse to get the final x. I did the same for the y but with arcsin and sin instead of cos

#

I'm curious to see how the shape of the ellipse changes as I change the parameters now too, I never really learned any of this officially so I don't really know why the ellipse popped out there.

#

ping me if someone's interested

sacred sparrow
#

I once tried to create a function that has a fixed distance to another function, so that for any function, I can find a function whose values all have a distance of >=1 to all values of the other function

#

but that was awfully difficult and restrictive

#

in coooontrast to your question

#

which is quickly solvable :) @clever sand

#

but we'll have to slightly redefine it

clever sand
#

I guessed that it's easily solvable
I just didn't know how so I challenged myself

clever sand
sacred sparrow
#

when viewing it from an analysis standpoint it'll seem difficult

sacred sparrow
#

that takes a function and converts it into a new one

clever sand
#

k?

sacred sparrow
#

we'll instead let our initial function be given as an equation

#

an arbitrary equation involving x and y

clever sand
clever sand
#

sure, go on

sacred sparrow
#

now, the graph for that equation is all points [x y] for which the equation is true

#

and we want to rotate each of these points [x y] by some angle a

#

which we can express in linear algebra:

#

as a product of a vector with a rotation matrix

#

meaning Rotation * Coordinates = Rotated_Coordinates

clever sand
#

as I said
I haven't got the faintest clue what vector multiplication is
I mean I do understand what you are doing though
ok interesting

sacred sparrow
clever sand
#

ok

sacred sparrow
#

you may accept that for now :D

#

the matrix multiplication yields us: x' = x*cos(a)-y*sin(a)

#

and y' = x*sin(a)+y*cos(a)

#

now why would that have any use?

#

well if you now take some arbitrary function, say ```
x+y = 5

#

which is just some random line

#

we can substitute the x with the rotated coordinate x'

#

and y with y'

#
x*cos(a)-y*sin(a)+x*sin(a)+y*cos(a) = 5
#

and now, we have the rotated graph by an angle a!

clever sand
#

is that how you calculate a rotation usually?

sacred sparrow
clever sand
#

is the way I did it fine though

#

how would you write it using the method I used?

sacred sparrow
#

whereas the principle of "let's just rotate every single point instead"

#

is applicable for arbitrary functions

#

they don't have to be continuous or anything

#

sry gtg

clever sand
#

what I did was a function that takes a specific point and outputs the rotated point, could you just use that function and do the matrix thingy using that (sorry I don't know exactly how that works so I'd like a clarification if that won't work) [I'm talking about the first line in the picture]

sacred sparrow
#

you can search for "point rotation in 2D or R²"

clever sand
#

ok thanks :)
how do I implement that in desmos if that's possible? I doubt it supports stuff like that

#

just curious

sacred sparrow
#

it'll only work for continuous functions and they aren't allowed to rotate far enough to potentially have 2 outputs

clever sand
#

anyway bye, I guess I'm gonna learn linear algebra now from random sources because I'm intrigued

#

thanks

sacred sparrow
#

so the method works, yes, but it'll only cover a small sample of possible functions

sacred sparrow
#

it's just sin & cos

#

for rotating an arbitrary point

#

nywys wish thee good luck, like the experimental spirit

#

🦇

clever sand
#

I'm more intrigued as to what the hell matrix multiplication is and vectors and all that
I've been hearing it thrown around in a variety of contexts so I'm curious as to what it holds

#

cya

#

.close

full forumBOT
#
Channel closed

Closed by @clever sand

Use .reopen if this was a mistake.

full forumBOT
#
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.

willow sundial
full forumBOT
willow sundial
#

I need help solving this integral

velvet sedge
#

a u-sub makes this become a little bit nicer integration by parts

willow sundial
#

what u-sub should i use?

glad hound
#

I thought to try (x-pi/2), but that doesn't take care of cos(nx)

velvet sedge
#

i think either way you'll need to use two integration by parts

glad hound
#

save the u-sub for later, and go with integration by parts first

#

Remember that pi is not a variable, and it can be moved outside with the 16

#

(the pi in the denominator... the one in parentheses is stuck for the moment)

willow sundial
#

thx

#

ill try solving it with that

full forumBOT
#

@willow sundial Has your question been resolved?

full forumBOT
#
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.

vast haven
full forumBOT
vast haven
#

I need help solving this frq question for precalc

#

<@&286206848099549185>

neon fulcrum
vast haven
#

I can't use discord on that computer so I had to take pic from another device

#

<@&286206848099549185>

full forumBOT
#

@vast haven Has your question been resolved?

full forumBOT
#

@vast haven Has your question been resolved?

full forumBOT
#
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.

strong pawn
#

How do we find (rs)^11 in D6 hexagon without brute force? r is rotation ccw, and s is flip across x axis.

fathom saddle
#

The dihedral groups obey:
r⁻¹s = sr

torn jolt
#

(rs)^6+5

strong pawn
fathom saddle
#

You can pass r through any s, just take the inverse when you do

torn jolt
#

Do you want to get reported

strong pawn
#

I split it like you asked

#

Wdym

spice knot
torn jolt
#

@fathom saddle Can't you split it?

strong pawn
#

I wasnt looking

#

i was counting my rs's

spice knot
#

rs^(6+5)

strong pawn
#

on the keyboard

#

mb

spice knot
#

lmao

#

"rsrsrsrsrsrsrsrsrsrsrs" never gets old

#

now split it like this:

strong pawn
#

Ok ya i get it

spice knot
#

rsrsrsrsrsrs rsrsrsrsrs

strong pawn
#

so u can write rs ^6 + 5 right

spice knot
#

make sure its (rs)^(6 + 5)

#

dont forget parentheses

#

rest assured this is the first time youve seen that

strong pawn
#

whats that supposed to do now

torn jolt
#

@strong pawn Since rs^6 and rs^5 are consecutive we can simply it to e (rs)

strong pawn
#

????????????

torn jolt
#

rs^(6+5) -> rs^6 * rs^5

strong pawn
#

Ya so now we got rsrsrsrsrsrs and rsrsrsrsrs

#

and yeah thats the same as rsrsrsrsrsrsrsrsrsrsrs

torn jolt
#

Yes

#

Shut up

strong pawn
#

then how tf do we get e (rs)

torn jolt
strong pawn
#

Yeah

torn jolt
#

s^2 = e

strong pawn
#

Cuz if u rotate it 6 times u get trhe same thing

#

And if u flip it twice u get the same thing

#

But then doesn't it change because they are not together

#

They are separate

#

rsrsrsrsrsrs

torn jolt
#

What I did was r(sr)^4

#

becomes r(sr(sr)^3)

#

That simplifies to r(s^2r^2)

#

@strong pawn Now what can be evaluated

strong pawn
#

i dontget it

#

so rn we goet (rs)^11 = (rs)^(6+5) = rs^6 * rs^5 = rsrsrsrsrsrs * rsrsrsrsrs

torn jolt
#

Yeah but we know r^6 = e already

#

So now we only have to worry about rs^5

strong pawn
torn jolt
#

rsrsrsrsr

fathom saddle
torn jolt
#

Ok you know what kaynex help you

#

Because I give up

#

I am retire

strong pawn
#

thanks bro

#

"pass r thoguh any s"

torn jolt
strong pawn
#

that sounds wack

torn jolt
#

Dam u hate me a lot

strong pawn
#

no i was being sarcastic

#

nah dw

#

everything is forgotten

#

jk

#

you suck

#

jk ^2 *

strong pawn
#

i dont get ur "pass r thoguh any s"

#

i do know a theorem

#

r^i s^j r^k s^l = r^(i-k) s^(j+l) if j = 1, and r^(i+k) s^l if j=0

#

but tahts only for rsrs

fathom saddle
#

That's just true in any dihedral group. rs = sr⁻¹

full forumBOT
#

@strong pawn Has your question been resolved?

#
Channel closed

Closed by @strong pawn

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.

quick fox
#

Can someone help me figure out what I'm missing for this problem?

quick fox
#

This was my attempt at a solution, but 0.436 m/s was wrong.

full forumBOT
#

@quick fox Has your question been resolved?

quick fox
#

<@&286206848099549185>

thin flint
#

you integrated with respect to V not t

quick fox
thin flint
#

you would just add -g to the result

#

and keep the rest

#

new bounds would be 0 and t

#

t being the time at which the velocity is measured

quick fox
thin flint
#

the + C is related to indefinite integrals

#

specifically because there is no starting point

#

you could have a starting time

#

t0

quick fox
#

.close

full forumBOT
#
Channel closed

Closed by @quick fox

Use .reopen if this was a mistake.

full forumBOT
#
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.

wanton basin
full forumBOT
wanton basin
#

What logarithm rules are being referred to here?

#

or arctangent rules?

#

Ok i have made signifcant progress

#

But I am still struggling with the bottom portion

gritty talon
#

from the second = sign to the third equal sign, it looks like ln 2 = (1/2) ln x

#

how would you solve for x?

wanton basin
#

maybe multiply the 1/2 over

#

so 1/2ln(2) = ln(x)

#

and then

#

exponentiate both sides

#

so e^1/2*ln(2) = x

#

is what I thought

gritty talon
wanton basin
#

oops

#

you are right

#

lol

#

so ln(4) = x

#

what about the bottom 2 though?

gritty talon
#

2ln(2) = ln (x)

#

e^(2ln(2)) = x

wanton basin
#

then bring the 2 in

gritty talon
#

x = 2^2 = 4

wanton basin
#

its ln(2^2)

#

ah

#

e^2ln(2) = x

#

is 4 = x?

gritty talon
#

ah no because remember exponent rules: x^(yz) = x^y * x^z

gritty talon
wanton basin
#

I messed up my order

#

It was this

#

the 1/2 ln(blank/5) refers to what though?

gritty talon
#

can you find out a way to combine all of the logs in the question?

#

hint: use log rules

wanton basin
#

is it just a subtraction

#

then division

#

so 8/5

#

?

gritty talon
#

yeah so 8 should go in the box

wanton basin
#

ok thanks

#

that answers my questions, I see what they were doing now

#

the way its ordered with all the steps disjointed makes it hard for me to parse

gritty talon
gritty talon
wanton basin
#

.close

full forumBOT
#
Channel closed

Closed by @wanton basin

Use .reopen if this was a mistake.

full forumBOT
#
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.

flat phoenix
#

can someone help me rq with this word problem i dont know how to start it off

flat phoenix
#

im not too sure how to start this off

exotic mason
#

0.9^3*807