#help-17

1 messages · Page 65 of 1

long flame
#

,w cos120 = -cos60

long flame
#

😄

#

okay then it makes sense my calculations were wrong

#

thanks

#

.close

vocal sleetBOT
#
Channel closed

Closed by @long flame

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.

marsh bluff
#

how is expansion of binomials related to combination?

round plover
#

if you look at the binomial (a+b)^n

#

when you're expanding it, you're basically picking between a or b, n times

#

if you pick a, k times, you have b n-k times, so you're on the a^kb^{n-k} term

marsh bluff
#

what do you mean by picking

round plover
#

but there are n choose k ways to pick k as from the n total brackets

#

(a+b)^n = (a+b)(a+b)...(a+b)

marsh bluff
#

ye

round plover
#

you can multiply this out by picking either a or b from each bracket

civic otter
marsh bluff
#

i dont understand

round plover
#

if you pick a every time, you get a * a * a * ... * a = a^n

marsh bluff
#

why are picking it out

round plover
#

look at the n=2 case

#

(a+b)(a+b)

#

to multiply it out, we do a*a + a*b + b*a + b*b

marsh bluff
#

yes

round plover
#

the a*a term is the same as picking a from both brackets

#

we have to multiply every term in every bracket by the terms in every other bracket

#

where do we get a*a + a*b + b*a + b*b from

marsh bluff
#

from a(a+b)+b(a+b)

round plover
#

are you familiar with FOIL

#

you don't need to expand the brackets like that

marsh bluff
#

ye

round plover
#

you multiply the first terms of each (same as "picking" the first term of each bracket, then multiplying them), then multiply the first term of the first bracket and last term of the second bracket, etc.

#

each multiplication requires picking a term from each bracket

#

in the longer set of brackets, (a+b)(a+b)(a+b)...(a+b), it's the same thing

#

you need to multiply a term from each bracket, which is the same as picking a or b for each bracket

marsh bluff
#

ok

round plover
#

so a term in the full expansion comes from a choice of a or b from each bracket

#

if you pick k a's, there must be n-k b brackets remaining

#

so you have an a^kb^{n-k} term

#

but there are n choose k ways to pick the k a's from the n brackets

marsh bluff
#

ok this is confusing

round plover
#

so this term has an additional coefficient of nCk

marsh bluff
#

what is the a term?

#

the a^2 term?

round plover
#

a isn't referring to the variable

#

it's just a term as in, some term

marsh bluff
#

ok

round plover
#

I'll swap variables

#

(x+y)(x+y)...(x+y)

marsh bluff
#

ok

round plover
#

a term in the expansion of this comes from picking some x or y

#

like, with (x+y)(x+y), we can pick x from both

#

to get x^2

#

or x from first, y from second to get xy

#

etc.

#

so each term, like x^2, xy, y^2, comes from these choices

#

in the general case (x+y)(x+y)...(x+y) with n brackets

#

we can pick x from k of these brackets to get x^k

#

but if we didn't pick x, that means we picked y for that bracket

marsh bluff
#

why is it x or y

round plover
#

I mean x or y from each bracket

marsh bluff
#

and it x and some other term

round plover
#

because each bracket is (x+y)

#

we can pick one from each bracket

marsh bluff
#

ok

#

so all terms in the expansion comes from two terms in the brackets

round plover
#

it'll come from one choice of x or y from each of the n brackets

#

we can look at the cubic case: (x+y)(x+y)(x+y)

#

if we pick x from all 3, we get x^3

#

if we pick x from the first, y from the second and third, we get xy^2

#

right?

marsh bluff
#

ye

#

we pick 1 term from each bracket

round plover
#

so with n brackets, (x+y)(x+y)(x+y)...(x+y)

#

if we pick k x's from among the n brackets

#

that means there are n-k brackets left over from which we pick y

#

so we have a x^k y^(n-k) term

marsh bluff
#

what does k x's mean

round plover
#

we pick x from k of the brackets

#

where k is just some number less than n

#

in the cubic case, we had k = 3, which is picking x from all 3

#

and k = 1, which is picking x from 1 of the brackets

#

it just means how many x's you have

marsh bluff
#

so n=k

round plover
#

no

marsh bluff
#

since n is also the number of brackets

round plover
#

k is the number of x we pick, only

#

we don't have to pick x from every bracket

marsh bluff
#

ok

#

so k<=n

round plover
#

in the cubic case, we could pick x from the first, and y from the last two

#

to get xy^2

#

this is an example of k=1

marsh bluff
#

ok

round plover
#

if we pick x from exactly k brackets

#

there are n-k brackets remaining from which we pick y

#

in the cubic case of n=3 and k=1, we had xy^2; note that 2 = 3-1

marsh bluff
#

im having trouble to understand k brackets

#

if k is the number of x

round plover
#

we have n brackets total

#

we're picking x from k of them

marsh bluff
#

ok

round plover
#

we have n=3 (because we have 3 brackets)

#

and k=1, because we picked 1 x

marsh bluff
#

k can be 1, 2 or 3

round plover
#

yes

#

any number less than n

marsh bluff
#

ye

#

but it can be 3

round plover
#

yes

#

if k = 3, then we pick x from all 3 brackets

#

and we get x^3

marsh bluff
#

ok

#

i get this part

round plover
#

if we don't pick x from a bracket, we have to pick y from that bracket

#

because we need something from each bracket

marsh bluff
#

ok

#

thats when k = 0

round plover
#

no

#

even when we had k = 1

#

we picked x from one of the brackets

#

that means we need y from the other 2

marsh bluff
#

yes but

#

when k = 0 we pick all other y

round plover
#

yes

#

but I'm saying you must have y in there even if k is not 0

#

we had y in there when k = 1

#

the only time you don't have any y is when you pick x from every bracket, so k=n

marsh bluff
#

ok

round plover
#

the number of x and y must add up to the number of brackets

#

because you need exactly one x or y from each bracket

#

so if you have n brackets, and you pick x, k times

#

you have n-k brackets where you must pick y

#

because k + (n-k) = n [read this as number of x + number of y = number of brackets]

#

is this okay?

marsh bluff
#

ok

#

ye

round plover
#

cool

#

so this choice of x, k times, and y, n-k times

marsh bluff
#

ye

round plover
#

gives a $x^ky^{n-k}$ term

twin meteorBOT
#

Desync

marsh bluff
#

yes

round plover
#

but, there's more than 1 way to pick x k times from n brackets

#

there are exactly n choose k ways

#

wait, I'm assuming you know the choose function

#

since you asked about combinatorics

#

is this correct?

marsh bluff
#

ye

#

im confused

round plover
#

alright cool

marsh bluff
#

theres 1 than 1 way to pick x k times from n brackets

round plover
#

sure, lets drop back to the cubic case

#

we have n = 3 here: (x+y)(x+y)(x+y)

marsh bluff
#

ok

round plover
#

and say we have k=1

#

so we want 1 x

#

well, we could pick the x from the first bracket

#

or from the second

#

or from the third

#

there are 3 choose 1 ways to pick that single x from the 3 brackets

marsh bluff
#

ok

#

ok

#

so this is where the coefficient appear

round plover
#

so more generally, there are n choose k ways to pick k x's from the n brackets

#

because we're choosing k brackets to pick x from out of n total brackets

marsh bluff
#

ye

round plover
#

that's exactly the binomial coefficients

marsh bluff
#

ye but why

#

why does it represent the coefficient of the terms

#

if its telling us the number of ways to pick x from the brackets

round plover
#

okay, so in the cubic case

#

we can pick x from the first bracket to get x * y * y = xy^2

marsh bluff
#

or

round plover
#

or we could pick x from the second to get y * x * y = yxy = xy^2

marsh bluff
#

yyx

round plover
#

yes

marsh bluff
#

3 choose 1

round plover
#

but all of these rearrange to xy^2

#

so you have (3 choose 1) * xy^2

marsh bluff
#

ye

#

then u have to sum them up

#

to simplify

#

xyy+yxy+yyx=3xyy

round plover
#

so that 3 is the coefficient

#

and it matches up with the number of ways to pick one x from three brackets

marsh bluff
#

im still confused

#

how does it represent the coefficient

#

if its the number of ways

round plover
#

each way of picking

#

gives us a copy of xy^2

#

okay?

marsh bluff
#

yes

round plover
#

so the number of ways of picking

#

gives the coefficient on xy^2 when you sum them upp

marsh bluff
#

ok

round plover
#

because if you have 3 ways of picking, you have 3 copies of xy^2

marsh bluff
#

if u phrase it like that

#

ye

round plover
#

the "ways of picking"

#

is given by 3 choose 1

#

because the choose function is defined to give the number of ways to pick

#

so if we have (3 choose 1) ways of picking

#

we have (3 choose 1) copies of xy^2

marsh bluff
#

ye

round plover
#

so the coefficient is (3 choose 1)

marsh bluff
#

interesting

#

so how is this related to the pascal triangle

round plover
#

pascal's triangle is just a way of writing out (n choose k) for various values of n and k in a systematic way

marsh bluff
#

how does a triangle made from adding the numbers above it gives us the coefficient of binomial expansions

#

why not give us the coefficient of trinomial expansion

#

oh u know

#

is there a trinomial theorem?

round plover
#

there is

marsh bluff
#

like

#

(a+b+c)^n

round plover
#

there's a general multinomial theorem

civic otter
marsh bluff
#

oh

#

is there a trinomial pyramid

round plover
#

I guess it'd be more of a tetrahedron

marsh bluff
#

oh

#

whats that

round plover
#

"pyramid" with 3 sides

#

"pyramid" technically should have 4 sides

marsh bluff
#

oh ok

round plover
#

I don't know how to draw one, and I don't think they're really used in practice

#

because we have a formula for the coefficients

marsh bluff
#

ok

#

is there a tetrahedron for the coefficient of trinomial expansion?

round plover
#

yeah, there probably is

#

but we don't use it

marsh bluff
#

maybe it can tell us some number sequence

round plover
#

you can go explore that if you wish

marsh bluff
#

ok

#

jk

#

thanks for rthe help btw

#

i really appreciate your help

#

and it really makes me understandthe topic better

round plover
#

np

#

combinatorics is fun, but a lot of the proofs are really condensed and hard to get into

marsh bluff
#

oh ok

#

have a nice day

round plover
#

you too, take care

#

remember to .close the channel if you don't have any more questions

marsh bluff
#

ok

#

.close

vocal sleetBOT
#
Channel closed

Closed by @marsh bluff

Use .reopen if this was a mistake.

marsh bluff
#

.open

#

.open

#

.open

round plover
#

it's .reopen

marsh bluff
#

oh ok

civic otter
#

.reopen

vocal sleetBOT
#

round plover
#

did you have a follow up?

vocal sleetBOT
#

@marsh bluff Has your question been resolved?

vocal sleetBOT
#
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.

elfin moon
vocal sleetBOT
elfin moon
#

Here given rank of matric is 2

#

So i tried to 3×3 and determinant 0

#

How to find T it then

full hatch
golden night
#

find the det in terms of t

elfin moon
#

I got t=0

#

I got t=3

#

By other matrix

full hatch
#

Wait are those two different matrizes?

woeful cloak
#

You should use the word submatrix here to fit the context. Saying "matrix" for a submatrix will confuse everyone

elfin moon
woeful cloak
# elfin moon

anyway, this is not 0 for just t=0, and note that this is not the only submatrix of dimension 3 either

elfin moon
#

That's why I got

#

T=3

woeful cloak
#

yes, t=3 should be the only values that makes every submatrix of dimension 3 have a determinant of 0

elfin moon
#

How to solve this one

#

I am not good at row operations

woeful cloak
#

well I don't see any other way than doing row operations. You could find the determinant of E if you are eager to do it by hand

elfin moon
#

Can you show me how to do it by row operations?

#

I can write one step

woeful cloak
#

There is probably a way of making two of any columns/rows be dependent, but then that would involve solving a system, so that's not really any better

#

anyway, start out by choosing a pivoting column

elfin moon
#

Multiplying first row with-1 and adding gives many zeroes

#

I don't know if it's a good idea

woeful cloak
#

well the first thing to notice here is that when t=0, we will have all of the rows/columns be independent, meaning the rank of this matrix is 4 in this case. So, now we want to check for when t!=0. What this means is that you can now multiply/divide a row by t without worrying if it'll change the result

#

so now, can you find operations that makes all of the elements in the first column (except for the first one) to be 0?

elfin moon
#

I don't know what to do with it

#

If we minus 4 column with 1st

woeful cloak
#

ok, I need some confirmation first, are we doing row operations or column operations?

elfin moon
#

I was doing row operations but when you are suggesting column operations

woeful cloak
#

technically doing column or row operations is fine, I just need us to agree on one

elfin moon
#

Let's go with row

woeful cloak
#

alright then

#

anyway, let's continue with the case when t!=0.
As you can see, a row operation R3-R4->R4 will make the first and second element on row 4 to be 0. Continue this with row 2 and 3 makes the first element on row 3 be 0. Now how can we make the first element on row 2 be 0?

elfin moon
#

If we multiply first row 2 with a t then subtraction with first row

woeful cloak
#

sure

#

ok, tell me what you have after doing those operations

elfin moon
woeful cloak
#

alright looks good

#

now before moving on, let's see what happens when t=1

#

what would be the rank of E when t=1?

elfin moon
#

Rank will be <=3

woeful cloak
#

yes, but further note that when t=1, the bottom three rows will be all 0, what this means is that there is only one vector that spans this matrix

#

meaning the rank of E is 1 when t=1

#

so now we need to consider the case where t!=0,1

elfin moon
#

Yes rank will be 1

woeful cloak
#

you can see what the pattern should be, just keep working down the rows and consider the cases until you have reached the final row

#

shouldn't be too bad since our matrix is very nice

elfin moon
#

Can you elaborate more about cases?

#

What do you want me to do with rows?

#

If I put t=0

#

Then rank is 0

#

Null matrix

woeful cloak
#

again no, like I have said, when t=0, all of the row vectors are independent

#

this is trivial when you write it out, so in this case the rank is 4. Meaning you don't care about the value t=0 anymore

#

what this essential does is it allows you to multiply by the scalar t. You usually can't do this when t=0, because then that operation wouldn't make sense

#

so a similar thing happens for t=1, what this just does is to make sure that t=1 is not a value that we care about, so we can multiply by the scalar (t-1) or (1-t)

#

our goal is still trying to row reduce the matrix

#

(note that you only need to do one more row operation and you are good to go)

elfin moon
#

Now idea

#

Because each operation is disappearing leading zeroes

#

And this is taking so much time for me to solve just 5 minute thing

#

.close

vocal sleetBOT
#
Channel closed

Closed by @elfin moon

Use .reopen if this was a mistake.

vocal sleetBOT
#
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.

unborn locust
vocal sleetBOT
unborn locust
#

Can someone teach me the steps for this?

boreal path
#

@unborn locust

unborn locust
#

Yes

boreal path
#

How do you find the area of a square base 2 and height 3

unborn locust
#

2x3

boreal path
#

Exactly

#

Base times height

#

Now hwat is our base here

unborn locust
#

2y+3

boreal path
#

remember multiplication doesn’t matter the order

#

2x3 equals 3x2 so it doesn’t matter what you choose as the bad

#

now what’s our heigh

#

t

#

if you chose 2y+3 as base

unborn locust
#

y-1

boreal path
#

So we just multiply them

unborn locust
#

Yeah

boreal path
#

Do you know to multiply (2y+3)(y-1)

unborn locust
#

Wdym?

boreal path
#

Like how to expand those brackets

unborn locust
#

aren't I supposed to expand and simplify it

#

Oh ok

boreal path
#

What did you get

unborn locust
#

2y^2 - 2y + 3y-3

boreal path
#

Collecting like terms what are we left with ?

unborn locust
#

Could you expand on that?

boreal path
#

Collecting like terms is like

#

x+3x+3 simplifies to 4x+3

#

The terms ahve the same pronumeral which is x

#

so we just add them

unborn locust
#

Oh so like 2y2 - 2y + 3y

boreal path
#

That simplifies to what

unborn locust
#

2y^2 - 5y = 3y

boreal path
#

How’d you get that

boreal path
#

and just simplify like you normally do

#

i think i confused you

unborn locust
#

2y^2 - 5y - 3?

boreal path
#

Close

#

-2y+3y isn’t -5y

unborn locust
#

Ohhh right nvm

boreal path
#

Do you underdtand the problem?

unborn locust
#

Yeah

#

Wait

#

Is it supposed to be 1y

boreal path
#

1y is equal to y

unborn locust
#

Yeah

boreal path
#

Yes

#

So we just write it as y

#

but you are correct

unborn locust
#

How would I put that in the equation?

boreal path
#

Well why do you think there’s an equation

#

there’s no equal sign anywhere

unborn locust
#

Oh right

boreal path
#

It’s simply 2y^2+y-3

unborn locust
#

Oh ok

boreal path
#

as the expression for the area

unborn locust
#

Ohh

boreal path
#

hope this jelped

unborn locust
#

Yeah thanks

#

There is nothing else right?

boreal path
#

Nope

unborn locust
#

Is that the final answer?

boreal path
#

ur done

unborn locust
#

Oh ok

#

It was actually simple, thanks a lot

boreal path
#

You can also solve similar problems

#

for example if you are asked that for a ttiangle

#

right angled

#

we know the area formula for a triangle

#

so we do the same thing

unborn locust
#

Oh ok, thank you

#

.close

vocal sleetBOT
#
Channel closed

Closed by @unborn locust

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.

naive sable
#

https://youtu.be/Ip3X9LOh2dk?t=504
I don't understand what he meant by this -- "If both b and c are non-zero then that b*c term tells you how much this parallelogram is stretched or squished in the diagonal direction."

The determinant measures how much volumes change during a transformation.
Help fund future projects: https://www.patreon.com/3blue1brown
An equally valuable form of support is to simply share some of the videos.
Home page: https://www.3blue1brown.com/

Full series: http://3b1b.co/eola

Future series like this are funded by the community, throug...

▶ Play video
errant warren
#

it is more of a rough intuition than an exact description, but as the terms b and c grow very large compared to a and d the parallelogram will sort of tend to be longer and thinner

#

if you consider how the matrix translates the vectors (0,1) and (1,0) which will end up being the sides of the parallelogram that is perhaps a way to visualise it

naive sable
#

hmm also ig the orientation of the area bc is opposite (to the area ad) so it's subtracted from b*d ?

errant warren
#

yeah that’s a good way to describe it

naive sable
#

Alright thanks

#

.close

vocal sleetBOT
#
Channel closed

Closed by @naive sable

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.

remote vector
#

Hey, I'm trying to understand a proof which I found online and I'm stuck at an apperently fact, namely that the red and the yellow angles are the same. Unfortunately the proof doesn't discuss it further and I can't figure out why the two angles of the same color are the same

remote vector
vocal sleetBOT
#

@remote vector Has your question been resolved?

vocal sleetBOT
#

@remote vector Has your question been resolved?

frozen cave
#

cyclic quadrilaterals my frend

#

BCQP is cyclic

#

so opposite angles are supplementary

#

cyclic means it can be inscribed in a cicrcle

#

and the diagram shows it being inscribed in a circle

#

@remote vector

#

so BPQ + BCQ = 180 so BPQ = 180 - BCQ = BCA

#

so BPQ = BCA

#

the yellow angles are equal

#

same for the red

#

does this answer your question?

#

In Euclidean geometry, a cyclic quadrilateral or inscribed quadrilateral is a quadrilateral whose vertices all lie on a single circle. This circle is called the circumcircle or circumscribed circle, and the vertices are said to be concyclic. The center of the circle and its radius are called the circumcenter and the circumradius respectively. Ot...

vocal sleetBOT
#

@remote vector Has your question been resolved?

remote vector
#

Yes, thanks a lot!

vocal sleetBOT
#
Channel closed

Closed by @remote vector

Use .reopen if this was a mistake.

vocal sleetBOT
#
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 shale
#

Tried integrating a semi circle got this weird thign

vast shale
#

$$\int_0^r (2\pi r \cos(x \frac{90}{r}) dx$$

#

$$\frac{2\pi r^2}{90} + C$$

twin meteorBOT
vast shale
#

the divison shouldn't be there right?

blissful sentinel
#

why are there degrees devastation

vast shale
#

$$ u = x \frac{90}{r}$$
$$ du = \frac{90}{r} dx$$
$$ dx = \frac{r}{90}du$$
$$\frac{2\pi r^2}{90} \int_0^r cos(u) du$$

twin meteorBOT
vast shale
#

I did $$\frac{90}{r}$$ because that's how you umm

twin meteorBOT
vast shale
#

you

#

find the radius of a cross section

#

with cos()

#

i think

#

cos(90) = 0 which would be the very end of the semi circle

blissful sentinel
#

Is your cosine in degrees??

#

If so sine is NOT an antiderivative

#

By the chain rule, the derivative of sine (in degrees) would be pi/180 cos (in degrees)

vast shale
blissful sentinel
#

The whole reason to use radians is that the derivative of cosine is -sine and the derivative of sine is cosine

#

If you scale the input differently, you need to use the chain rule to calculate what the result should be

vast shale
#

This was mentioned nowhere before

#

Ty

blissful sentinel
#

It works the same as any other type of scaling a function

#

👍

#

No problem

#

It can be trippy

vast shale
#

.close

vocal sleetBOT
#
Channel closed

Closed by @torpid horizon

Use .reopen if this was a mistake.

vocal sleetBOT
#
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.

strange tiger
#

hello could i get help with this question? the proposition hint is included

strange tiger
#

used lim laws to get to here but now i am stumped 💀

ebon rapids
#

You can’t use limit laws in the original just yet because your denominator will approach 0

strange tiger
#

ohh

ebon rapids
#

The limits won’t exist if you split it like this

strange tiger
#

my original idea was to say that since f(x) is a polynomial u could simplify the expression in the numerator and then factorize

#

and pray to god that one of the factors are x-3

river minnow
#

What should the nominator approach so that the overall limit may exist given the denominator approaches 0?

ebon rapids
#

The key is to use the proposition hint

strange tiger
#

sometimes

river minnow
#

Yeah, so f(x) - x - 4 should approach 0 as x -> 3

twin meteorBOT
ebon rapids
#

You should be able to answer the question by now

strange tiger
#

OH

#

OHHH

#

THANK U

#

.close

vocal sleetBOT
#
Channel closed

Closed by @strange tiger

Use .reopen if this was a mistake.

strange tiger
#

wow

vocal sleetBOT
#
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.

urban obsidian
vocal sleetBOT
urban obsidian
#

how would i do this?

#

Well intuitively i made the inscribed squares vertexes touch the midpoints of the bigger square

#

but idk how i could justify that

rugged orchid
#

Have you learned calculus

urban obsidian
#

surely i can't be lost in the weeds of optimization

rugged orchid
#

That’s different to having to justify it

#

You just need to find the area

#

This is obvious yes?

vocal sleetBOT
#

@urban obsidian Has your question been resolved?

urban obsidian
rugged orchid
#

Use Pythagoras

#

If it’s multi choice

#

You just need to find the answer asap

#

Justification is not needed

#

But if you did want to justify I would probably use calculus

urban obsidian
#

i know how to find the area

#

of the inscribed square

#

i mean how do i know

#

which one minimizes the area?

#

like what orientation

urban obsidian
#

it was correct but it was just a hunch tbh

rugged orchid
#

You just need a hunch

#

For MCQ

#

If you want to justify it you probably need calculus

urban obsidian
#

i assumed the orientation was 90 degree

#

well "sleeping rectangle"

#

whatever you call it

#

exactly what you drew tbh

rugged orchid
urban obsidian
#

is there anything i can "memorize" though?

rugged orchid
#

Yeah

urban obsidian
#

i can do calc yeah but is there any facts i can memroize

rugged orchid
#

I mean that’s the obvious hunch

urban obsidian
#

about maximizing shit

urban obsidian
rugged orchid
#

I guess you can try to visualise it

#

They won’t make it too hard in mcq

#

That’s not the point of mcq

#

MCQ pretty much (in my experience) are always the ones where they mostly have tricks you can use

#

Like there’s a fast and short way

#

And if you do the short way it gives you more time for other questions

urban obsidian
#

i just saw some people were spreading "concepts" relevant to this

#

something like this

#

ofc i guess i could prove via calculus

#

or could i

#

i might be rusty actually so maybe not

#

but where does this originate from

rugged orchid
#

Well all this can be proven via calculus

#

As I’m dumb I would do it with calculus

#

But maybe there’s another way geometrically

#

I’m too dumb to see one if they exist

urban obsidian
rugged orchid
urban obsidian
#

onc ei prove it once ig it gets easier to remember

urban obsidian
#

was looking more for geometric proof ig

rugged orchid
#

Although I do remember that the biggest volume for surface area is a sphere

#

And likewise perimeter and area for circle

#

Because bubbles are spherical

#

It’s got the least potential energy or something

#

Something physics something idk

urban obsidian
#

hmmmmm

#

welp lemme try

#

thanks for the lead

#

i guess you're right

#

in that the orientation that you chose

rugged orchid
#

There’s also one about hexagons

urban obsidian
#

it's probably the easiest to do in terms of finding the area

rugged orchid
#

They tile the plane with the least perimeter

urban obsidian
#

ooo never heard of that tbh

rugged orchid
#

Something about honeycombs I think

urban obsidian
#

sure i'll try to check it out if necessary

#

anywa ythanks

#

.close

vocal sleetBOT
#
Channel closed

Closed by @urban obsidian

Use .reopen if this was a mistake.

rugged orchid
#

But this is really just random reading and stuff so I don’t expect schools to expect this to be just a known fact unless you specifically covered this

vocal sleetBOT
#
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.

craggy imp
vocal sleetBOT
craggy imp
#

Don’t know what to do

lilac plaza
#

,rccw

twin meteorBOT
lilac plaza
#

I'm not sure but does knowing 2sin(Φ)cos(Φ) = sin(2Φ) help..?

sudden cloud
#

Use this formula

#

Products to sum

#

Nvm I read the q wrong

craggy imp
#

so

#

what do i do?

sudden cloud
#

Theta = A

#

And the other = B

#

So its 1/2(a+b)

craggy imp
#

ahh

#

i see

sudden cloud
#

👍

craggy imp
#

i will try doing it now'

sudden cloud
#

👍

#

.close

#

yoo can I not close it

craggy imp
#

i got it it is D

onyx gulch
craggy imp
#

thanks mate

onyx gulch
sudden cloud
craggy imp
#

thanks

vocal sleetBOT
#

@craggy imp Has your question been resolved?

#
Channel closed

Closed by @craggy imp

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 sleetBOT
vast shale
#

can anyone help me

#

get another channel

open spade
vocal sleetBOT
#
Channel closed

Closed due to the original message being deleted

vocal sleetBOT
#
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 citrus
vocal sleetBOT
twin citrus
#

and then autor writes this :

#

so my issue here is that in the first formula x goes to 0 from negative direction as well

#

and therefore I can not understand how we get second equation from the first one

twin citrus
#

so what next

flat whale
#

well you wanted x from 0^-

#

so x=-1/n will work for that direction

#

what does n approach?

#

writing n -> +- inf doesn't quite make sense

twin citrus
#

so this both are true

#

but i want to get second formula of e

#

not this

peak matrix
flat whale
flat whale
peak matrix
flat whale
#

oh

twin citrus
flat whale
#

right. so what's your question

twin citrus
#

i want to get secod eq from the first

peak matrix
#

To make that conclusion, you need just the positive direction

twin citrus
#

i understand now

#

tnx

#

.close

vocal sleetBOT
#
Channel closed

Closed by @twin citrus

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.

dim silo
vocal sleetBOT
dim silo
#

Why am i not getting y as 3.16

mild flower
#

you didn't do the power rule right

#

,tex .log rules

twin meteorBOT
#

hayley!

vocal sleetBOT
#

@dim silo Has your question been resolved?

dim silo
mild flower
#

$2\log y$ is equal to $\log(y^2)$

twin meteorBOT
#

hayley!

dim silo
#

oh ok

vocal sleetBOT
#
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.

knotty snow
vocal sleetBOT
lilac plaza
#

,rccw

twin meteorBOT
knotty snow
#

How do we approach this

#

I don't understand

#

and I have a quiz today

#

pls help

lilac plaza
#

I hope this helps

#

I'm a bit rusty on this topic

terse forum
#

your handwriting looks neat

knotty snow
#

this does, but why did you switch the function of the 3rd part to 3x/2 + 2a

lilac plaza
lilac plaza
obtuse sierra
# knotty snow

for the function to be continuous on all real x, it should also be continuous on those points where it is changing its definition.

twin meteorBOT
#

Dyssrupt

knotty snow
#

yeah

#

but then how do u solve for a and b? do you set it equal to 4 as mentioned in the 3rd piece

obtuse sierra
#

what is the definition of function at x = -1?

knotty snow
#

ax-b if x <_ -1

obtuse sierra
#

and for x>-1?

knotty snow
#

2x^2 + 3ax + b if -1 < x <_ 1

#

4, if x > 1

obtuse sierra
knotty snow
#

but a and b are not defined

obtuse sierra
#

just substitute the value of x

vocal sleetBOT
#

@knotty snow Has your question been resolved?

vocal sleetBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

vocal sleetBOT
#
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.

naive sable
vocal sleetBOT
naive sable
#

$$\Gamma(\pi) = \int_{0}^{\infty} t^{\pi - 1} e^{-t}dt$$ $$Let u = e^{-t}$$ $$\implies du = -e^{-t}dt$$ $$ln(u) = ln(e^{-t}) = -t$$ $$\implies t^{\pi - 1} = [-ln(u)]^{\pi - 1}$$ $$\Gamma(\pi) = -\int_{0}^{\infty} [-ln(u)]^{\pi - 1}du$$

#

just a sec

undone pond
#

0 and infinity are limits correct? and not 0^infi

twin meteorBOT
#

Climate

naive sable
#

What should I do now ? Any substitution?

undone pond
naive sable
#

ahh alright let me try ibp

#

yeah done

#

.close

vocal sleetBOT
#
Channel closed

Closed by @naive sable

Use .reopen if this was a mistake.

vocal sleetBOT
#
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.

bleak crow
#

Find all continuous equations $f : \mathbb{R} \to \mathbb{R}$ such as:
$f(\sqrt{2}x)=2f(x)$ and
$f(x+1)=f(x)+2x+1$
For all $x \in \mathbb{R}$

twin meteorBOT
#

BeeReallyYum

bleak crow
#

I figured that f(x)=x^2 is a solution

#

but it was just a guess and I couldn't prove it

#

I got 4f(x)=f(2x)

hybrid flicker
hybrid flicker
bleak crow
#

right I think I can prove it easily with induction

#

but I don't think that's enough

#

because that's only one solution there could be more

#

but yeah i'm kinda stuck there

hybrid flicker
#

prove that f(n) = n^2, you're almost there

distant eagle
bleak crow
#

like that doesn't really account for the other possible solutions

distant eagle
bleak crow
#

wait i'm sorry could you explain how that works

hybrid flicker
#

it's the base 2 version of decimal numbers basically

bleak crow
#

so a number's binary representation?

hybrid flicker
#

nono

#

Decimal numbers can be written as (integer).abcd or integer + a/10 + b/100 + ... AS LONG AS the sum is finite

#

diadic numbers are basically the equivalent with powers of 2 :

#

it can be written as integer + a/2 + b/4 + c/8 + ... with a finite sum

#

Or even better, as k/(2^n) as explained above

bleak crow
#

oh alright got it

distant eagle
bleak crow
#

that makes sense

distant eagle
#

2-adic numbers are a different, more complicated thing

hybrid flicker
#

we get confused between diadic and diadic very easily

#

anyways

hybrid flicker
bleak crow
#

yeah so how does that help in this problem

hybrid flicker
#

then prove it is true for all diadic numbers

#

then, use that the set of diadic numbers is dense in R

bleak crow
#

alright yeah got it

#

but I guess I can't prove that it's true for all diadic numbers using induction right?

hybrid flicker
#

you can, because all diadic numbers can be written as k/2^n

#

so your induction will be on n

bleak crow
#

ohh alright that makes sense

#

but then how would I prove it's also the only solution

hybrid flicker
#

you're showing that f solution => f(x) = x^2

#

so there is at most one solution which is the square function

#

reciprocately, you can show that this possible solution works

#

and so x^2 is the only solution

bleak crow
#

i'm sorry i'm kinda confused

#

how can we prove there is only one solution by showing it works

hybrid flicker
#

that's not what we're doing

#

we're showing "if f is a solution, then it HAS to be this one"

#

Let S be your set of solution functions. You want to show S = {x-> x^2}

#

so you show $S\subseteq {x\longmapsto x^2}$

twin meteorBOT
#

rafilou2003

hybrid flicker
#

because you know the other inclusion is true, so you only have to prove this one

bleak crow
#

oh alright yeah that's clear

#

thank you for your help!

#

.close

vocal sleetBOT
#
Channel closed

Closed by @bleak crow

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.

glacial meadow
#

What do we have to do to the conversion factor if we are dealing with units that measure area?

glacial meadow
#

cube it?

#

or swuare it

pale perch
#

the factor tends to be (the conversion factor between the units)^2, so say you have 1m^2, thats 10000cm^2 since 1m=100cm

thin vale
#

1m=100cm, so 1m*1m=100cm*100cm => 1m^2=10,000cm^2

vocal sleetBOT
#

@glacial meadow Has your question been resolved?

vocal sleetBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

vocal sleetBOT
#
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.

sweet minnow
#

I'm really stumped with this

vocal sleetBOT
sly sierra
#

does $\theta^2 \tan \theta$ do anything naughty at $\theta = \pi/6$?

twin meteorBOT
sly sierra
#

any discontinuity, does it blow up to infinity, etc

sweet minnow
#

Honestly I'm not sure

vocal sleetBOT
#

@sweet minnow Has your question been resolved?

vocal sleetBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

vocal sleetBOT
#
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 shale
#

Why is this definite integral not equal to 1 - pi/2 ? I can't come up with the solution wolfram alpha suggests

paper depot
#

show work?

vast shale
#

gimme a sec

solid sage
#

,w integrate x^2/(1+x^2)

twin meteorBOT
solid sage
#

Lmao yeah thought so, arcsin is the root a^2-x^2

solid sage
#

You used the wrong inverse trig identit

#

Derivative of arcsinx is not that

#

It’s arctan which you’re meant to use

vast shale
#

ahhh you're right haha

#

thank you!

solid sage
#

Yeah silly mistakes

#

Alg

vast shale
#

.close

vocal sleetBOT
#
Channel closed

Closed by @marble perch

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.

dusk jackal
vocal sleetBOT
dusk jackal
#

how do you solve part a and b

#

something to do with Normal forces and stuff

#

i get that the weight of the person is 50*9.8

#

meaning force down

#

but the other force which is the normal is not equal to WEIGHT on the person cuz the lift is going down?

#

not sure where to go from there

vocal sleetBOT
#

@dusk jackal Has your question been resolved?

vocal sleetBOT
#

@dusk jackal Has your question been resolved?

vocal sleetBOT
#

@dusk jackal Has your question been resolved?

vocal sleetBOT
#

@dusk jackal Has your question been resolved?

simple mason
#

@dusk jackal
I recommend you to watch this video that will help you understand how to solve this kind of questions
https://youtu.be/sVVKpRvuNG0

This physics video tutorial explains how to find the normal force on a scale in a typical elevator problem. It discusses how to calculate the apparent weight of a person when the elevator is at rest, moving upward with constant speed, downward with constant velocity, accelerating upward or downward. It uses free body diagrams and net force cal...

▶ Play video
vocal sleetBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

vocal sleetBOT
#
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.

woven gate
#

(\phi:\bR[X,Y]\to \bR[t]:X\mapsto t^2,Y\mapsto t^3)
prove that Kernel of (\phi) is ((X^3-Y^2))

twin meteorBOT
hybrid flicker
#

!status

vocal sleetBOT
#
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'm told it's wrong
4. I got an answer and would like my work checked
5. I have a question about someone else's worked solution
6. None of the above
woven gate
#

pandaHmm I how do I show there isn't any other polynomial without X^3-Y^2 as a factor in the kernel

hybrid flicker
#

You want to show Ker(phi) = (X^3-Y^2)

#

so it's a double inclusion principle

#

you show Ker(phi) subset of (X^3-Y^2)

woven gate
#

yea that idk how to do

worthy citrus
#

the obvious hint here is a bit revealing so i'll try and be annoyingly vague: you're trying to show that something in the kernel, f, is divisible by (x^3-y^2), assume it's not, then how can you write f? (not actually a proof by contradiction)

paper depot
#

im not sure thats correct

hybrid flicker
hybrid flicker
#

We're dealing with polynomials, so we have division

woven gate
#

do I quotient R[X,Y] by that ideal, then look at all the other elements except the 0 element

worthy citrus
#

another annoying vague hint: 7 = 3*2 + 1

woven gate
#

alr so div algorithm

worthy citrus
#

yeah

woven gate
#

I've not seen it for 2 variable polynomials

#

how should the degree of r[X,Y] look like?

worthy citrus
#

it wont matter

hybrid flicker
#

well it will if you want to apply division

worthy citrus
#

actually its a good point whether it does general to multivariate polynomials i dont know off the top of my head

hybrid flicker
#

the degree would be deg(X^nY^m) = n+m

worthy citrus
#

since R is a pid then probably does

#

i was just mirroring what you do in the single variable case but here you might need grobner basis shite

woven gate
hybrid flicker
#

nah bruh just deal with it as if deg(X^n Y^m) = n+m

worthy citrus
#

sure i think its fine, you deffo can write f = g*(x^3-y^2) + r(x,y)

#

the degree of r wont matter as you'll soon see

worthy citrus
woven gate
#

alr so
p=q(X^3-Y^2)+r
where r has degree <3?
how would X^5= X^2(X^3-Y^2 )+X^2Y^2
deg of r is 4

hybrid flicker
#

if r is of degree < 3, then r = aX^2 + bXY + cY^2 + ...

woven gate
#

catThin4K wot, yea but what went wrong in my example

worthy citrus
woven gate
untold surge
#

You can just show that
$\mathbb{R}[X,Y]/(X^{3}-Y^{2}) \to \mathbb{R}[t]$ is injective actually

twin meteorBOT
#

Cogwheels of the mind

untold surge
#

Because if (X^3-Y^2) is strictly contained in the kernel, this homomorphism isn’t injective

woven gate
#

I think I should get it now

#

I'll do the rest, thanks a lot

untold surge
# twin meteor **Cogwheels of the mind**

x=X+(X^3-Y^2), y=Y+(X^3-Y^2). The image of f(x)+g(x)y, which is f(t^2)+g(t^2)t^3, being zero must imply that f(x)=g(x)=0 otherwise there is some even degree polynomial =odd degree polynomial

vocal sleetBOT
#

@woven gate Has your question been resolved?

woven gate
untold surge
#

Np

woven gate
#

thanks yall @worthy citrus @hybrid flicker

#

I'll close now

#

.close

vocal sleetBOT
#
Channel closed

Closed by @woven gate

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 sleetBOT
vocal sleetBOT
#

@quaint creek Has your question been resolved?

vocal sleetBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

vocal sleetBOT
#
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.

vagrant cypress
#

pls help

vocal sleetBOT
vagrant cypress
#

function question btw

karmic imp
#

What's the goal?

#

Factor?

vagrant cypress
#

determine if the relation is a function

#

then find the domain and range

#

i did the first one

#

y= 2x^2 -3

#

?

harsh canopy
#

yeah

#

is that a function?

vagrant cypress
#

yep

harsh canopy
#

ok

vagrant cypress
#

question is to determine if the equation is a function or not

harsh canopy
#

so that question has been answered

#

anything else neeeded?

vagrant cypress
#

now i need to find the range

harsh canopy
#

ok

vagrant cypress
#

i already have the domain

#

(-inf , inf)?

harsh canopy
#

do you know where the minimum value is?

harsh canopy
vagrant cypress
#

OHHH

#

I SEE

#

so

#

[-3, inf)

harsh canopy
#

yes

vagrant cypress
#

question

#

do we isolate y on one side

#

?

harsh canopy
#

with this one yes

vagrant cypress
#

would i do the same with c?

#

the 2nd equation in the picture

harsh canopy
#

with c it might be more helpful to isolate x

vagrant cypress
#

oh why could u explain

harsh canopy
#

because you have y^2, when you square root you will get +-

#

so it might be easier to get x = ....

vagrant cypress
#

how about e?

#

do i add the 5x to 2x

harsh canopy
#

with e, i would isolate y

vagrant cypress
#

so c

#

i got

#

-6x = -3y ^2 -9

#

then I divide all by -3?

harsh canopy
#

divide it by -6

#

to get just x =

vagrant cypress
#

so we divide to get the first variable by itself?

harsh canopy
#

yeah

vagrant cypress
#

x = .5y^2 +1.5 ???

#

is that right

#

after dividing by -6

harsh canopy
#

yeah

#

so think of what the equation y = 0.5x^2 + 1.5 would look like

vagrant cypress
#

not a function

harsh canopy
harsh canopy
vagrant cypress
harsh canopy
#

because of the variable switch

#

yeah like that

harsh canopy
vagrant cypress
harsh canopy
#

yeah

#

thats the easy way to spot if it is or not

vagrant cypress
#

and a function is supposed to have only 1 output

harsh canopy
#

true

#

so it isnt a function

vagrant cypress
#

could u help me with smth else

#

f(-x) = |x|-3

#

i got -1?

harsh canopy
#

wdym?

vagrant cypress
#

like the

#

f(x) but inside the x is a value

#

and u subsitute the x value in an equation with the x value from f(x)

harsh canopy
#

so what are you trying to figure out?

vagrant cypress
#

5 a

harsh canopy
#

evaluate it at the specified value?

#

is that what that says

vagrant cypress
#

ya

harsh canopy
#

but f(-x) is a graph

vagrant cypress
#

i’m rlly not sure

#

we did this in class but with a diff equation

#

and did nothing with graphs

#

E

harsh canopy
#

oh it means like that

#

well then the graph is exactly the same

#

if you sub -x into that equation of |x| - 3

vagrant cypress
#

would there be a domain and range for this

harsh canopy
#

yes there is always a domain and range

vagrant cypress
#

(-1.3, inf) ??

harsh canopy
#

is there any boundary on what x can be?

vagrant cypress
#

wdym by boundary

harsh canopy
#

as in can x be any number, and if not, is there a boundary (or an interval) on what x is

vagrant cypress
#

x is approximately -1.286

harsh canopy
#

that doesnt have any relevance to the domain and range of this graph though

vagrant cypress
#

is domain

#

(-inf, inf)?

harsh canopy
#

yeah

vagrant cypress
#

and the range would be um

#

after doing it

#

i got

#

6y = 7x + 9

#

and dividing that by 6

#

the range would be 7/6?

#

cuz y = mx + b

#

waiy

#

No