#help-0

1 messages · Page 869 of 1

west geyser
#

Someone please help me with this question, it's killing me

#

I don't even know how to start the solution

#

it has this solution but I don't understand any of it

placid zinc
#

What is the "join" of two points?

west geyser
#

the line segment, I'd wager

#

I'm fairly sure that I have to use the Section Formula somehow

#

but I'm not able to

#

it just leads me to a very complex solution

#

and no question would be that complex

#

god this is literally the first question

lapis sluice
#

,rotate

oak chasm
#

Well, sine gives the y value of a unit circle and cosine gives the x value.

So, x = cos(θ) and y = sin(θ), so y = sin(arccos(x)).

And y = sin(arccos(x)) can be written y = ±sqrt(1 - x²).

west geyser
#

it will have this topic

wispy wing
#

what about mine?

#

i need help

west geyser
quartz parrot
#

evaluate this

#

I feel like there is a formula im dont know of

glass lichen
#

it's arithmetic

quartz parrot
#

yes

#

idk

oak chasm
#

@quartz parrot Change it into this:

= (-8 + 1) + (-4 + 1) + (0 + 1) + (4 + 1) + ⋯ + (400 + 1)
= (1 + 1 + ⋯ + 1) + (-8 + -4 + 0 + ⋯ + 400)

alpine sable
#

ig imma use the channel

#

oh

oak chasm
#

And you can continue simplifying from there.

#

Like factor out the 4.

#

And so on.

rigid kiln
#

this is going on forever, should this end up just being 2n+1?

oak chasm
#

@rigid kiln Sorry, this channel is busy.

rigid kiln
#

whoops, sorry if i'm interrupting

#

yeah, sorry, didn't notice

alpine sable
#

ig ill use another channel then

rich basin
#

(b) please

#

why that?

placid zinc
#

Why not just compute 1 + z + z² + z³ + z⁴?

rich basin
#

how would i?

placid zinc
#

z² = z•z

#

So you'd multiply by z itself

rich basin
#

yeah hat is what i did

#

i made it into exponentual form

#

and then i change it to (e^(10ipi/4)^n

#

in which n is for each of the {1,2,3,4}

placid zinc
#

Oh I see, you can't add exponential forms

#

So, go back to rectangular

rich basin
#

yeah

#

you mean the polar form?

#

so what i did was change it to exponential form first

#

in which i would be able to do the ^n really easily

#

and then i then change to polar fomr

placid zinc
#

I think you're saying polar when you mean rectangular

#

If you have it in cosθ + isinθ

rich basin
#

yeah

#

yeah i changed to rectangular

placid zinc
#

Exponential form is really the polar form

#

Well, now that you have that, adding them should be easy

rich basin
#

it is pretty difficult

#

let me write out what i have right now

placid zinc
#

Especially since z² = i

rich basin
#

$1+\cos\left(\frac{5\pi}{2}\right)+i\sin\left(\frac{5\pi}{2}\right)+\cos\left(\frac{5\pi}{4}\right)+i\sin\left(\frac{5\pi}{4}\right)+\cos\left(\frac{15\pi}{4}\right)+i\sin\left(\frac{15\pi}{4}\right)+\cos\left(\frac{10\pi}{1}\right)+i\sin\left(\frac{10\pi}{1}\right)$

ocean sealBOT
#

BorutoEyePower

rich basin
#

wait why is z^2 = i?

#

this is when i changed into exponential form to easily evaluate or i could of just skipped and use de`moivre theorem

#

@placid zinc anything i can do, or is this just too much, i could of easily simplify it with an easier step?

alpine nacelle
placid zinc
#

So demoivre and exponential are really the same trick

#

That is, if
z = e^(π/4)
Then you can square both sides to get:
z² = e^(2π/4) = e^(π/2) = i

karmic quail
#

gcf (7, 15)?

rigid kiln
#

7 is prime

rich basin
#

wait how did you reduce z = e^(pi/4)

alpine nacelle
#

z = e^(i*pi/4)

#

exponential form

rich basin
#

oh yeah

#

so what is the method you are thinking

#

so when it is multipled by powered by 2, it would be an imaginary number only

alpine nacelle
#

1 + z + z² + z^3 + z^4 = z + iz + i

#

that would be a way

rich basin
#

how did you simplify so quickly?

#

so z^2 would then be i

alpine nacelle
#

so z^4 would be -1

rich basin
#

yeah

alpine nacelle
#

and z^3 = z^2 * z = i*z

rich basin
#

because in a circle, it is on the left hand side of the complex plane

#

right

#

okay thanks this helped alot

alpine nacelle
#

or you can just write the sum as (z^5 - 1)/(z-1) = -(z+1)/(z-1) since it's a geometric serie, it works too

#

at some point you have a bit of calculation you have to do

rich basin
#

is there any way in which i can visualise e^i*degrees

#

desmos doesn't seem to offer anyway since i = root(-1) is invalid

alpine nacelle
#

e^(i*angle) is of modulus 1

#

he is on the unit circle

rich basin
#

yeah, so it essentially a circle basically

alpine nacelle
#

then you just have to visualise the angle

rich basin
#

and the n*e^(i *angle) is

#

and n basically modifies the range

alpine nacelle
#

the distance from the origin

rich basin
#

okay, thanks, this helped alot

quartz parrot
#

i dont know what to do with the other braket side

#

wait

#

so id get 400+(5050-12)4

#

so I get 20552

wispy wing
#

can i have some help <@&286206848099549185> ive needed help for 3hrs now

#

im 15 and im 1 question away from finishing doing 5hrs of maths

#

i just want to go to sleep, can someone help me on the last question, please?

oak chasm
#

@quartz parrot No, there aren't 400 terms.

wispy wing
stable dune
#

is this right

oak chasm
#

@stable dune Sorry, this channel is busy.

wispy wing
#

@oak chasm can u help me out bud?

oak chasm
#

@wispy wing First, find the coordinates of P. Then, find the angle pointing at P from the origin. Then, the slope of the tangent is perpendicular to that. Now you have the slope and a point on the tangent line, so use point-slope form.

wispy wing
#

theres a graph?

oak chasm
#

Oh, you don't need to find the angle.

#

You can just find the slope from O to P.

#

Take the perpendicular slope to get the slope of the tangent line.

#

Then you have a point and a slope.

wispy wing
#

i hate to be annoying but i dont know how

oak chasm
#

Which part?

wispy wing
#

just the whole thing in general to be honest

oak chasm
#

OK, so x² + y² = 90, right?

wispy wing
#

yes

oak chasm
#

And they give you x = 3.

#

So, 3² + y² = 90. Solve for y.

#

What do you get?

wispy wing
#

10?

oak chasm
#

Why do you say 10?

wispy wing
#

sorry 9

oak chasm
#

OK, so it's ±9.

#

3² + y² = 90
9 + y² = 90
y² = 81
sqrt(y²) = sqrt(81)
|y| = 9
y = ±9.

alpine sable
oak chasm
#

@alpine sable Sorry, this channel is busy.

#

@wispy wing So, what does the problem say about whether y is positive or negative?

wispy wing
#

it doesnt say anything

oak chasm
#

Yes, it does.

wispy wing
#
  • ?
oak chasm
#

Why?

wispy wing
#

Because P has a x - coordiante?

oak chasm
#

Sorry?

#

What is a "x - coordiante"?

wispy wing
#

i dont know

#

sorry

#

im trying my best but its 00:38

#

and im tired

oak chasm
#

It would be better to sleep and then do the problem.

wispy wing
#

its the last problem

#

ive done about 70 problems in 5hrs, just this to go

oak chasm
#

It's possible to become too tired to do problems or to work your brain so hard that you can't think about anything difficult.

#

The solution is rest if that's possible, not finishing the last problem right now.

#

You'll get better results and learn more from it.

wispy wing
#

ive got physics for tommorow though

oak chasm
#

Yes, but like you said, it's only one problem, and it's like a five minute one. You can do it in the morning if you have time.

wispy wing
#

can we just finish it quickly now?

#

i dont want to go to sleep thinking about it

#

@oak chasm im sorry if im being annoying

#

but i really want to get it done

oak chasm
#

No, it's not that, it's that we're supposed to guide you and it's more like I'm doing it for you.

wispy wing
#

its not 5 min for me, ive not even learnt it

ocean sealBOT
oak chasm
wispy wing
#

is there a link i can have on how to learn mine?

wispy wing
#

thanks

#

ill try my best

oak chasm
#

Point slope is easier than their slope intercept form, though.

wispy wing
#

can u go through with me again?

#

is x 3?

#

@oak chasm

#

mate im trying

rich basin
#

z is unkown, but they want us to expand and simplify

#

but is there a way to do this a more smarter way than just bruteforcing it?

warm brook
#

@rich basin idk what you mean smarter, I'd just multiply it out

#

There aren't any tricks in this one in particular

rich basin
#

like how did you expand it?

wanton folio
#

whats up

#

whats the problem

warm brook
#

Like idk, do the right 2 things first

#

You mention z is known, what is it dyslexia moment

wanton folio
glass lichen
rich basin
#

yeah

#

is it (a-b) (a^2 + ab + b^2)

#

and (a+b)(a^2-ab + b^2)

wanton folio
#

look

rich basin
#

what about them in here?

wanton folio
#

two key observations

rich basin
#

i don't quite see it

wanton folio
#
  1. the multiplication of e^stuff is 1
#
  1. use the definition of the complex cosine
rich basin
#

yeah i got (z+2)(z^2 -2z +4)

#

which looks like (z+2)^3

#

but then how do i get this down?

warm brook
rich basin
#

isn't it?

bleak ridge
warm brook
#

(z+2)^2 = z^2 +4z + 4

rich basin
#

yeah?

warm brook
#

z^2 - 2z + 4 \ne z^2 + 4z + 4

wanton folio
#

when you multiply it out you get z^3+8

rich basin
#

yeah

wanton folio
#

what's the problem then?

rich basin
#

i just learned something

#

about how to fast multiply this

#

which i never knew

#

so when you have something that have powers that are negative of each other

#

it completely removes the powers

wanton folio
#

do you mean a^b*a^(-b)=1?

#

@warm brook Are you french?

warm brook
#

Why?

rich basin
#

yeah

wanton folio
#

I'm studying french rn 🙂

warm brook
#

very cool

#

@rich basin I'm still weird about the (z+2)^3 comment and I want to make sure you meant z^3 + 8 or that it was just a mention that it looked kinda like (z+2)^3

#

as z^3 + 8 is not (z+2)^3, it's z^3 + 2^3

wanton folio
#

actually there's a famous theorem that goes like (a+b)^3=a^3+b^3

warm brook
wanton folio
#

but unfortunately it only holds for sedeonic a,b

#

kirby, veux-tu parler français avec moi?

warm brook
#

eh , pas maintenant

rich basin
#

because (a+b)^3 = (a^2 -ab + b^2)

warm brook
#

(a+b)^3 = a^3 + 3a^2b + 3ab^2 + b^3

devout summit
normal chasm
#

Can someone help me with question 1?

glass lichen
hushed pasture
# normal chasm

the equation of any circle is: $(x-a)^2+(y-b)^2 = r^2$ where the center is $\Omega = (a,b)$ and the radius is $r$

ocean sealBOT
wooden crag
#

I've looked at explanations of significant figures and it doesn't quite make sense to me
how many significant digits are there in 1.008?

wooden crag
#

uhhh
4?

#

2

#

but isnt 1.080 more precise than 1.08

opal mesa
#

1.008 has 4

#

1.080 has 4 too

wooden crag
#

1.800 has 2?

opal mesa
#

NO

#

4

wooden crag
#

4 and 2

opal mesa
#

If there is any N front of the zero then You include it

wooden crag
#

five and five

#

thiknign
how do you figure that one out

opal mesa
#

3

wooden crag
#

i wanna say 6 but that sounds wrong

opal mesa
#

3 is the first non zero digit

#

Sorry one sec

wooden crag
#

i mean, it feels like the entire number conveys information

opal mesa
#

@wooden crag I think there are three basic rules for significant digits

#

The first one is that any non zero digit is considered a significant digit

#

Then if there are any zeroes between non zero digits, then you consider them signififsnt too

ocean sealBOT
devout summit
#

If $n=pq$ for two primes $p$ and $q$. Then, $\phi(n)=(p-1)(q-1)=70$.

ocean sealBOT
#

Euclid31415

devout summit
#

$\phi(n)=n\prod_{p|n}\left(1-\frac{1}{p}\right)$

ocean sealBOT
#

Euclid31415

devout summit
#

There is no need of that.

ocean sealBOT
devout summit
#

That's what I did

ocean sealBOT
devout summit
#

No. I assumed n=pq first and then wrote phi(n)

#

Oh no I didn't notice

#

Then, if $n=p^aq^b$ then, $\phi(n)=(p-1)p^{a-1}(q-1)q^{b-1}$

ocean sealBOT
#

Euclid31415

devout summit
#

I think you just have to consider different cases and check...

alpine sable
#

hey could someone look at this and let me know if it’s right

alpine sable
#

thanks

silver current
fierce basalt
#

i suppose a hint could be use logs

fierce fern
#

what is the two possible roots of √36?

silver current
#

so 5.7^x =0.2

dim oasis
#

The step where absolute value comes into play is often skipped

ocean sealBOT
#

lexitorius

fierce fern
#

then is -6 counted as a root of 36

dim oasis
#

It shouldn’t really be but usually yeah

fierce fern
#

ok thanks

fierce basalt
#

do you know logarithms?

fierce basalt
ocean sealBOT
#

Swag369

fierce basalt
#

idk latex properly lol my b

silver current
#

what is latex

fierce basalt
#

its the fancy math typing

#

you knoow how the tex bot had the +/- 6

#

thats written with the $$

glass lichen
ocean sealBOT
glass lichen
#

also it said to use log not log_(5.7)

fierce fern
#

value of √25/36?

fierce bluff
placid zinc
#

What can't you plug in?

fierce bluff
#

ah thats it?

#

so 1 and square root +-2

glass lichen
#

Can you plug in -100000?

placid zinc
#

You're right, you can't plug in 1,√2,-√2

#

You can't plug in even more than that, though

fierce bluff
#

what else?

#

I think its just asking for domain

placid zinc
#

Number under a square root can't be negative.
x + 1 ≥ 0

fierce bluff
#

ah oh yeah

#

could u show how I would write using interval notation and union symbol

placid zinc
#

Those are your discontinuities. Everything else is continuous

#

[-1,1) U (1,√2) U (√2, inf)

fierce bluff
#

yeah ok thats what i was thinking for union

#

interval notation is the line right?

stiff pawn
#

should be closed on -1

fierce bluff
#

yeah square on -1 for me as well

#

ok thanks

rich basin
alpine sable
#

we know a+b is line segment AC

#

now if we have that OC starts at the midpoint then we need to scale this (a+b) by something that would cut it in half

#

thus we get 1/2 * (a+b)

#

did i make a feasible problem based on the figure on the first picture?

#

(i only used the left figure the right figure is only optional)

knotty badge
#

Where is that on a ti-84

#

Where is Z Alpha

rich basin
knotty badge
#

Guys please I need help

wary stream
alpine sable
#

lmao mans asked for help on an exam

#

<@&268886789983436800>

sly mantle
#

@knotty badge is this a timed graded test?

knotty badge
#

It’s not a “legit” exam

sly mantle
#

"legit"?

knotty badge
#

It is a test indeed

#

But it’s not graded as a test

#

It’s practice and it’s still graded

#

And it’s stressing me out

#

I just need to know where z alpha button is on ti-84

wary stream
knotty badge
#

I really don’t need help on the question I just need to know where that button is

#

That’s all I need guys

wary stream
#

I'm not even sure if that button does exist on a calculator. If that's probability and stat, and you need z, there's a z table that you can look up

tired drum
#

How would you do this, I get X>-7 but for some reason I don’t get how it’s also X<5/2

knotty badge
#

Hey if you had round to fourth decimal and your answer is 0.4469 would it now be 0.45

bleak ridge
#

No

#

It would be if it was 0.4496

knotty badge
#

So 0.447 would be correct right

wary stream
#

No

#

Count how many decimals you have

wary stream
tired drum
knotty badge
#

0.4469=0.447

wary stream
bleak ridge
#

Yes

#

0.4470 is the same as 0.447

wary stream
frozen echo
#

Can anyone tell me how to calculate solstice equinox?

#

I'm trying to understand the formula I have to use.

knotty badge
#

Is a number unusual if it’s less than 0.05 or greater

tired drum
devout summit
ocean sealBOT
#

Euclid31415

oblique stirrup
#

how do i approach this question?

If cos(10)=sin(θ)and 0<θ<90, then
θ =  ? degrees
devout summit
alpine sable
#

$x^2 -2(y)^2 = 1$
solve pls

ocean sealBOT
#

Aldrich

alpine sable
#

ans x=3 y=2

austere urchin
alpine sable
#

cos10=sin(90-10)

#

theta=80

devout summit
#

Its even in the name. "complementary sine" or "cos"

alpine sable
shy thicket
#

pft idk

oblique stirrup
devout summit
#

Yes! sin(80 degrees)=cos(10 degrees)

oblique stirrup
#

oh thhe key said 0.8

#

ok

alpine sable
# shy thicket

thats nice but where do we get an integer solution from?

devout summit
oblique stirrup
#

mb

alpine sable
#

Ye guys study a lot

#

I am busy in PUBG

#

What a mess....

oblique stirrup
#

feels like the map has 0 gravity

alpine sable
#

I see

#

Things are opposite in my country

oblique stirrup
#

yeah i know its popular outside

alpine sable
#

That was going HOT

#

It's all like CS : GO

devout summit
fierce bluff
oblique stirrup
alpine sable
fierce bluff
#

can someone explain why theres a - on the numerator?

oblique stirrup
#

it means the result is negative unless the result is negative and therefore positive, i think

rich basin
#

how do we do (d) ?

rich basin
#

<@&286206848099549185>

oblique stirrup
#

to find a coterminal angle u just add/minus 360 right

oblique stirrup
#

hell im inputing wrong answers .-.

#

actually blind

rich basin
#

anyone help me do (b)

alpine sable
small helm
#

and since it's a square BD and DC forms a 90 degree angle with the other lines that are connected to it

rich basin
#

yeah

small helm
#

so

rich basin
#

i got it

#

how would you find the intersectiion

#

would that jsut be the mid point for (e)

small helm
#

you basically just find the equations for BD and DC

#

then solve for x,y

rich basin
#

Okay i got it

small helm
#

since x,y in the two equations should be the same

rich basin
#

how do we do (d) for this?

#

i mean (c)
\

small helm
#

if you're trying to find the two point

#

and correct me if I'm wrong about this

#

but if you're just trying to find the two points that divide DE into 3 equal parts

#

then you can just use the equation to find the distance between two points

#

except instead of knowing the second point, you have to use the slope and the distance

rich basin
#

what equation would that be?

small helm
rich basin
#

I can't really see images dammit

small helm
#

ok so

#

what you're trying to find

rich basin
#

so i did what you told me to

#

to find the vectors between hem

small helm
#

is a point that is on the line DE

rich basin
#

whichc is {4 , -4}

#

and then i divided it by 3

#

wait what is the right answer

small helm
#

uh

#

lemme check

rich basin
#

how would we do (d) then?

#

like i don't know how can i reprsent it using d and e?

small helm
#

ok so

#

you have the equation of DE

#

in the form of y=mx+b

#

then you have then equation to solve for the distance

rich basin
#

yeah

#

what about (e)?

small helm
#

not sure

ripe tendon
#

does the order of these symbols matter?

#

like could I do L | D' and it would be the same thing?

small helm
#

no

ripe tendon
#

no to the top or bottom

#

sentence

small helm
#

the order does matter

#

that says the probability of D' given that L is true right?

ripe tendon
#

im seeing it for the first time right now im not quite sure what it means to be honest

#

I'd assume you are right

small helm
surreal meadow
#

P(A n B) = P(A | B)P(B) is kind of circular here lol

small helm
#

I think what it's supposed to mean is just P(AnB) = P(a)P(b)

#

because if we're just talking about intersection, then it doesn't have to be conditional

rich basin
#

this is the solution for (e)

#

but i can't put in for some reasons, the screenshot?

#

okay now it works

#

but why is it that the they change the vectors to become (b-a)

#

and not (a+b)

plush moon
#

what happend to this : f(x) = 4x+1

to be this : g(x) = ( 4x+1 ) + 3

i need some help sadcat

graceful cave
#

Isn't that g(x) = f(x)+3?

plush moon
hardy gulch
#

so what does it mean to +3

#

what move is it
and by how many units

plush moon
#

Offset 3 units to the right

Offset 3 units to the top

Horizontal stenosis with a factor of 3

Vertical dilation with a modulus of 3

hardy gulch
#

yeah

#

what would +3 look like

#

suppose i had a bunch of points on the graph

#

i +3 to all of them

#

what happens

plush moon
#

@hardy gulch

rich basin
#

(A)

clever folio
#

Maybe it's a symmetry type thing?

#

Like the triangle formed by OP and the x axis seems similar to the one formed by OR and the x axis

#

Which makes me feel like it would be -3+4i or something.

#

But that's just a vague guess.

rich basin
#

@clever folio you got it somehow, but i don't know how multiplying it by i makes it like that?

#

isn't it rotating by 90 degrees anti-clockwise

#

when multiplied by i

clever folio
#

I didn't multiply by i

#

Are you asking because you wanna do it that way?

rich basin
#

what did you do?

#

just want your thinking

clever folio
#

I looked at the geometry being shown

#

Take the perpendicular to the x-axis and P and look at the triangle formed. It is similar to the one you'd get if you take the perpendicular to the x-axis thru R

vale wigeon
#

yes, multiplication by i corresponds to a 90° ccw rotation about the origin.

clever folio
#

Using complex numbers will probably be a lot more elegant and easy lol

#

Would what I did be equiv to multiplying by i^2?

#

Nah wait nvm lol

vale wigeon
#

i mean this question mentions complex numbers directly

rich basin
#

wait if you multiply by i^2]

#

it wouldn't be -3+4i

clever folio
#

Yeah I said nvm because I wa being dumb with that

#

Lol

rich basin
#

I will be back, I have to go for something really quick. Be back

carmine lion
#

how to solve such systems quickly

#

yes

rich basin
#

okay i am back @clever folio

clever folio
#

I think you are just mixing something up when you mult by i is all.

#

It seems like it works when you do that.

rich basin
#

like aren't they perpendicular once i saw it?

clever folio
#

What do you mean?

#

They're perpendicular yah.

rich basin
#

so can you go with your method?

#

@clever folio what did you exactly do to find that solution?

clever folio
#

Make two triangles by drawing vertical lines from P and R to the x axis

#

Notice that these two triangles are basically the same but one is rotated and translated

rich basin
#

yeah

clever folio
#

So the lengths correspond in such a way that to get from the origin to R you would go left by 3 (so -3) and up by 4

#

It's a more complicated solution than just multiplying by i

rich basin
#

wait so how is the triangle rotated?

#

is it triangle rotated by the origin?

#

or is it from the placement?

clever folio
#

It's rotated and translated

rich basin
#

Rotated from what reference?

clever folio
#

Rotate the OP triangle I mentioned clockwise and shift it left

#

Seeing as this is not the solution the exercise intends I doubt it's worth worrying a bunch about lol.

rich basin
#

what i'm confused is what axis are you using to rotate them?

clever folio
#

I'm not sure how to better explain rotating a triangle clockwise. :/

#

You see the op triangle I'm talking about right?

rich basin
#

yeah

#

but then like where are you rotating it around?

#

and by how many degrees?

clever folio
#

So rotate that triangle clockwise until P is on the x-axis lol

rich basin
#

okay

clever folio
#

Now shift that triangle left until its hypotenuse lines up with OR

#

The vertical and horizontal legs give you the coords of R

rich basin
#

so let me assume that the triangle is OPR?

clever folio
#

No

#

Different triangle

#

Make a perpendicular to the x-axis thru P

rich basin
#

with the triangle or with the entire box?

clever folio
#

Call the pt on the x-axis B or something. This triangle would be OPB or whatever

rich basin
#

if triangle, what triangle would the points be?

clever folio
#

Just told you the pts

rich basin
#

okay

#

so the triangle is OP with the x axis that is perpendicular to the line P

clever folio
#

No that is not what I said.

clever folio
rich basin
#

is it a right angled triangle?

clever folio
#

Yes it is a right triangle

rich basin
#

yeah that is what i was thinking about

clever folio
#

Ah okay

rich basin
#

so looks like this right

clever folio
#

Yep basically

rich basin
#

okay

clever folio
#

Rotate it clockwise and shift it left til it lines up with OR

rich basin
#

yeah

clever folio
#

You know the vertical and horizontal legs of the new rotated shifted triangle

#

They tell you the coords of R

rich basin
#

like this right?

#

the little slash up the top denotes the rotation

clever folio
#

Yeah looks right

rich basin
#

oh right, that is pretty good. Thanks

#

what would exactly be the complex nubmer way of looking into this?

clever folio
#

Multiplying by i

#

It'll be way simpler than this lol

#

i(4+3i)=4i+3i^2 =4i-3=-3+4i

#

It gets the same answer in much easier way.

rich basin
#

so how you identify that they are peerpendicular

#

is it through using the geometric theorem, that bisecting diagonals within a square are perpendicular to each other

#

forming a right angle triangle

clever folio
#

You mean the two numbers -4+3i and 3+4i?

rich basin
#

yeah

clever folio
#

I'm not exactly sure I know there are formulas and stuff for it but I haven't dealt with complex numbers in a while

rich basin
#

okay thanks, this helped alot

alpine sable
clever folio
#

Don't quote me on that though lol.

devout summit
cedar prism
#

Hello guys I need help can anyone help me ?

alpine sable
cedar prism
#

I think I solved a but i didn't understand what do they mean by the minimum values

alpine sable
# alpine sable

Let OA = a and OB = b.
Find vector of OD and then ratio of OF:FD and EF:FA

coord bash wud be a fun way to do this

vale wigeon
cedar prism
vale wigeon
#

min(x,y) is equal to whichever of x and y is smaller

#

for example min(420, 69) = 69

#

this problem tells you that in fuzzy logic val(P & Q) = min(val P, val Q)

cedar prism
cedar prism
#

Or minimum

vale wigeon
#

what do you think

#

what could min(x,x) possibly be, if not x

rich basin
devout summit
ocean sealBOT
#

Euclid31415

rich basin
#

aren't all real numbers complex?

devout summit
#

Yes. They are a subset of complex numbers

rich basin
#

isn't this a non-zero compelx number?

devout summit
rich basin
#

like if you take a look at 3 -2i there are information about the complex number already, so it wouldn't be zero

devout summit
#

Yeah it totally applies here

devout summit
rich basin
#

Okay, aren't conjugates just refelctions?

devout summit
#

Yes they are reflections about real axis

rich basin
#

so if you have a position vector for them, and draw a line to them. They would just form a rombus

devout summit
#

$\overline{3-2i}=3+2i$

ocean sealBOT
#

Euclid31415

devout summit
#

We just flip the sign of imaginary part

rich basin
#

but then perpendicular is more visualised through geomtry

devout summit
rich basin
#

I mean, in order to start with this you need to first prove it with something you know

#

which is geometry

devout summit
#

It starts with Euler's formula and why multiplication by complex numbers corresponds with rotations and scaling

rich basin
#

yeah

#

oh right i get it

#

i could start visualising it in euler's formula

#

okay thanks

balmy zinc
#

Hi i dont know how to do these questions

alpine sable
#

The lesson you're training on is transformations of functions, right?

balmy zinc
#

yes

alpine sable
#

Okay. Let's see c)i). The way it's displayed can be a bit confusing, but when you multiply both sides by 2 you can start to understand what you're supposed to do.

#

y = 2h(x). Which means that for each input of x, you'll get twice the output of the original function.

#

So in the original function, if x = 0, y =1. In this newer one, if x = 0, y = 2(1)

alpine sable
real crescent
#

hi can someone help

balmy zinc
#

@alpine sable so do i multiply y-coordinates by 2?

alpine sable
#

Yea

#

I have this cheat sheet that my teacher actually gave me in case I'm not available to explain in detail the rest

#

It seems you're just doing the stretches now so don't worry about the rest.

alpine sable
# balmy zinc Hi i dont know how to do these questions

But if I'll explain the horizontal stretch, when here in c) ii) it tells you that when you enter an X into the function, you'll half that X before you input it.

Originally X = 2 gave you Y = 1, but here since you half the X before adding it in, you'll need the X to be 4 to give you the same Y = 1.

balmy zinc
alpine sable
#

Actually you'd be multiplying them by 2.

#

Since you need twice the X to give you the same Y.

#

It's like someone weakened the X and you're giving it reinforcements.

#

But don't worry it's usually only the f(x) changes that are counter-intuitive.

balmy zinc
#

ohh i see

#

thanks i understand it more now

tacit kernel
#

The sum of two numbers is 13. Twice the larger number is 8 more than 4 times the smaller. What are the numbers?

#

What does the 8 more than 4 times the smaller mean?? 😖

alpine sable
#

The smaller multiplied by 4

#

Then add 8 to that

tacit kernel
#

oooh

#

so 2x = 4y + 8???

alpine sable
#

Yep

tacit kernel
#

Alright thanks

alpine sable
#

nn

thick ferry
#

can someone help answer q 74 and 76

vague coral
#

f(g(x)), you replace the x in f(x) with g(x)

balmy zinc
#

@alpine sable wait for questions like y= h(x/(random number)), would it mean you always multiply x-coordinates by 2 since you need twice the x before halving the fraction to get 1?

alpine sable
#

In this case it was x/2 so you multiply it by two.

#

If it was h(2x) you divide by 2

#

Really just do the opposite of whatever he does to the x

alpine sable
thick ferry
static kindle
#

what do the square brackets mean?

vale wigeon
#

nothing

fierce linden
#

Is my algebra right so far?

#

<@&286206848099549185>

spring aspen
fierce linden
#

tyty

young warren
#

how is my answer not correct, shouldnt the product rule be used here>

devout summit
#

That last "u" should have been "c"

hollow pelican
#

hi guys how do i differentiate this?

graceful yoke
#

You bring -2t behind t and multiply it by t to which gives you (-2t^2)e and then you subtract 1 from the power which gives you a power of -2t-1.All together the answer would be s'=(-2t^2)e^-2t-1

young warren
hollow pelican
tawny fable
#

Hey there,
I need to find the value of sup(A), inf(A), min(A), and max(A). Or - prove that it doesn't exist.

My see that there is not sup(A) and max(A) but I don't know how to write it down and prove it.
I showed that 2 is inf(A) and min(A), but I couldnt continue from there.
I am sitting on this one for hours... any clue?

forest jacinth
#

Using the product rule, $\frac{ds}{dt} = \frac{d}{dt}(t)e^{-2t} + t\frac{d}{dt}(e^{-2t})$

ocean sealBOT
#

JarrGarde

forest jacinth
#

This should be alright, although I am a bit tired

static kindle
#

how do you find the bearing?

graceful yoke
devout summit
ocean sealBOT
#

Euclid31415

devout summit
graceful yoke
#

Oh why is the order switched around in this case?

devout summit
#

You treated e^{-2t} as power rule…

#

And moreover it has an extra “t” multiplied on the outside!!

snow pawn
#

hello

#

If you have a limit function, where f(0) is not defined

#

the assignment states that f(0) = 1 because of this

#

and then they ask me find f'(0) and f''(0). not sure how to begin this assignment..

devout summit
alpine sable
#

Why is the marked thing there? Like how did we get that its equal to the right hand or left hand side?

rustic junco
#

How do you find x?

chilly panther
# rustic junco How do you find x?

You can work out how many degrees total there are in a 5 angled shape by dividing it into triangles and using the fact that the sum of the angles in a triangle is 180 degrees. That should start you off at least

fresh fulcrum
#

I had a question on a number theory exam.

P=110322353973061799

P contains a five character HEX subliminal message.

Using n=10007 as the base extract the five decimal coefficients of the polynomial generated by n that P represents.

Not expecting to get a full answer but maybe some pointers to how do I go about solving this.

fallow cradle
#

Hi, this is a pretty dumb question but I can't seem to figure out where I went wrong?

#

I am given this equation and Im trying to find the roots

#

while not knowing what y is

#

So I found this as a root

#

but the actual answer is

#

What gives?

#

And delta (the stuff under the root idk what it's in english) would be 4y+8 which the correction confirms

#

Nvm im rlly dumb

bold panther
#

helppp how is this wrong? if tanx = 2t/(1-t^2) then isnt sinx the value on the numerator @-@?

karmic falcon
#

hi

#

i have an exercise

#

given the are of circular sector= 16pi find the perimeter of this sector

graceful yoke
#

16 pi?

#

wait no 8 pi + 8

digital needle
#

hi i need help

#

with this ques

old sluice
#

So yes, sinx is the value of the numerator

pliant zephyr
digital needle
#

ik

#

just figured it out

graceful yoke
#

How do you algebraically prove that sqrt(2) is irrational?

bold panther
karmic falcon
old sluice
#

I'm very sure that sinx is the numerator

graceful yoke
# karmic falcon how did you do it

You can find the radius of the segment by square rooting the 16 and taking the pi away and then you do pi times 2r which is 8 pi which is the curve part of the segments length then you just add 2r to 8 pi for the 2 radius length lines attached to each end of the curve and go into the middle of the circle

#

Oh wait I think I forgot about the angle part with fetur/360

bold panther
old sluice
#

🤨

graceful yoke
#

Yea idk then 😂

karmic falcon
#

are you sure that the radius is found that way. I think the formula is S=(n*r^2*pi)/360

#

where n is the degree of the angle

graceful yoke
#

Yea your right I forgot about the angle part at the begging sorry 😅

old sluice
karmic falcon
#

no problem

old sluice
#

Does it count brackets?

karmic falcon
bold panther
#

no :(

#

im just gonna skip that problem and do a different one

orchid python
#

how can I solve this?

#

anybdoy??

spring kiln
#

use rules for manipulating det

#

let me get a good reference for you

#

There we go

#

Let me know where you think we should start. Hint: transposing the original matrix means its det is still = 3

#

We can also swap rows and columns without changing the value of the det

#

except in sign !

#

3 -> -3

#

etc

#

@orchid python

chrome ice
#

does sin(a+b/2) have a formula of its own?

spring kiln
#
subtle seal
#

Good day! I'm trying to understand polynomial factorisation in the complex set then coming back to R set. say for example we have $P(x)=x^4+x^3+x^2+x+1$ what do we do in order to transform it into $z^2-\alpha$ to solve for the complex roots. for P(x) our prof multiplied P(x) by (x-1) to get $z^5-1$ and then find its roots. How do we figure out that?

ocean sealBOT
visual lava
#

any helpers

#

nvm brb

placid zinc
#

@subtle seal
One way might be a geometric series:
1 + x + ... + xⁿ = (x^(n+1) - 1) / (x - 1)

#

In general it's a common factoring trick you'll get used to:
(x - 1)(1 + x + ... xⁿ) = x^(n+1) - 1

subtle seal
#

excellent thank you! that makes sence

#

I suppose this is solely for polynomials with 1 as the coefficient for all its terms correct?

placid zinc
#

Yeah there's no similar trick

#

Well, if they're all the same coefficient you could factor it

subtle seal
placid zinc
#

The roots of x⁵ - 1 are
1
e^(πi/5)
e^(2πi/5)
e^(3πi/5)
e^(4πi/5)

#

@subtle seal
If you take any of those to the power 5, you get 1

alpine sable
#

Does someone know why the truth table of logical implication is like it is?

alpine sable
#

why is it b ?

placid zinc
#

Or, sorry, double all of those exponents

subtle seal
#

so $x^5-1=(x-1)(x-z_{1})(x-\overbar{z_{1}})(x-z_{2})(x-\overbar{z_{2}})$ Now how do we get p(x)?

placid zinc
#

I messed it up haha

ocean sealBOT
#

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

subtle seal
#

the other z1 is the conjugate

#

don't know how to add the bar in latex sorry xD

#

do we divide it over (x-1) to get back to p(x)?

placid zinc
#

z1, -z1, z2, -z2 are all of the roots we've found

#

So you have the factored form of P(x) right there

subtle seal
#

what about the (x-1) that we initially multiplied by to get x^5-1?

placid zinc
#

I'm confused. Are you starting with P(x), or trying to find P(x)?

subtle seal
#

Starting with it and trying to find its factorised form

placid zinc
#

z1, -z1, z2, -z2 are all of the roots we've found
So you have the factored form of P(x) right there

#

Note that multiplying by x - 1 put it into a form that gives the roots easily

subtle seal
#

I see the root of x-1 is irrelevant

#

perfect! thank you very much. you cleared up a lot of confusion

placid zinc
#

Np! Feel free to ask if you need anything else

haughty forge
#

Does anyone know what does x #=3 means?

#

Or like x + y #> 5 for example?

vernal thunder
#

Now if you were to plug any value to x you should get a y value that lies on graph a

azure jungle
#

Need help with derivations

alpine sable
#

Don't know anything about derivations

oak basin
#

May someone help me understand a question I have about a math problem it's kinda confusing

It's: If RS= 23-2x , ST = 9x-5 and RT = 39 Find RS

alpine sable
#

Sure

oak basin
#

I can send a pic if that helps at all :3 but idk if It should adds to 39 because it's on a line yk and the line total is 39 so yeah

orchid python
#

how can I solve it @spring kiln

tight locust
#

homogenous systems of linear equations are equations which lack a constant term, hence the zero vector is always a solution.

#

the trivial solution is the zero vector.

#

hence you want to find the values of a such that the only solution to this system is the zero vector.

#

@orchid python

karmic sandal
#

If x = - 1 that would be positive right?

alpine sable
#

what would be positive?

karmic sandal
#

X+2 part

#

(+) (-) (this part can also be positive right? )

#

@alpine sable

alpine sable
#

I don't get your question to be honest

warm brook
karmic sandal
#

Which is contrary to what I sent above

warm brook
#

no because -1 is not in (-infty,-2)

karmic sandal
#

Thanks @warm brook

low dove
#

I need to describe a class of sequences that satisfy this condition on the image. Like is it convergent or not, is it fundamental or not and so on. I guess that all x(n) , n > n(epsilon) don't belong to epsilon neighborhood of point a. So can I say that this sequence is unbounded?

robust phoenix
#

is it possible to multiply those ?

#

2 matrices

low dove
#

I think no because the number of columns of the first matrix does not equal the number of rows of the second matrix but I am not sure

robust phoenix
#

What's the area of this ?

small bear
robust phoenix
#

I have an answer but i'm not sure

#

I think it

small bear
#

Use it, another way would be to construct a square, and find the area of that square, and remove the three other triangles, let me make an image

#

What did you get

robust phoenix
#

I did all of that and got 14

#

I just want to double check

small bear
#

That looks good

robust phoenix
small bear
#

Yes, substituting i=12 and b=6 into the formula gives 14

sharp fjord
#

should that marked square be there or not, because I have notes saying it shouldnt and im confused

low dove
#

I think it should be there

wind hawk
shut temple
#

How can i solve this w/o l'hospital

vital inlet
#

13 pls

elfin talon
warm brook
ocean sealBOT
warm brook
#

substitute f(ax) and g(bx) for sin(ax) and sin(bx) respectively where a=7pi and b=2pi

elfin talon
# vital inlet 13 pls

X-sqrt(5) = 0
Therefore x = sqrt(5)

Also:

x + sqrt(3) = 0
Therefore x = - sqrt(3)
S.S = {-sqrt(3),sqrt(5)}
So d is the right answer

warm brook
#

@shut temple yes, it’s pretty clever, but for things like this, i’d just recommend putting it into a form of a limit that you already know the answer to (if possible) then proceed

alpine sable
#

for this division statement i keep getting -x is that right?

zealous ruin
#

Is that long division?

alpine sable
#

ye

#

im trying to solve for the oblique asymptote in a rational function

zealous ruin
#

Here's a step-by-step solution

alpine sable
#

im getting the same as this

#

but i dont understand the bottom part

zealous ruin
#

Retrace the example problem here, it might help you understand the principles of long division better

alpine sable
#

also does horizontal asymptote on a slant jus mean oblique asymptote?

zealous ruin
#

English is not my first language, no idea. Let's ask <@&286206848099549185>

alpine sable
#

How do i derive this

#

I got but i'm not sure

#

Didn't simplify yet

crimson blade
#

then take the inverse so you can move it up to the numerator

#

then just use the power rule to differentiate it normally

alpine sable
#

Yeah i did that's what i got but everyone in the class has a different answer

crimson blade
#

what was their answer?

alpine sable
crimson blade
#

oh yeah

#

because the differentiation is linear, you could take out the 8 first

#

to go from d/dx[8/sqrt^3(x)] to 8 • d/dx[1/sqrt^3(x)]

alpine sable
#

Hmm

graceful yoke
#

Oh so derive does mean the same thing as find the derivative of.

alpine sable
#

Yes it does

crimson blade
#

yeah that is the way

8 • d/dx[1/sqrt^3(x)] then becomes 8 • d/dx[x^(-1/3)]

graceful yoke
#

Sorry I was unsure of the word so I didn't help

alpine sable
#

It's okay

crimson blade
#

then 8(-1/3x^(-4/3))

#

why would it be -2/3?

alpine sable
#

1/3-1 is -2/3

crimson blade
#

its -1/3-1

#

so its -4/3

#

because when you move the term from the denominator to the numerator, the power is inversed

alpine sable
#

OH

#

Right

crimson blade
#

you get it?

alpine sable
#

Yep

#

Thanks

crimson blade
#

np

ionic inlet
#

I don't really understand how to do this. I'd know how to do it if the 5^(sec(-5x)+1) wasn't there or if it was only that but I don't know how to do it with both of them

clever folio
#

Does u=sec(-5x)+1 not work?

#

I have not done any calc in ages so I could be wrong tho lol

devout summit
clever folio
#

That makes sense lol

bleak ridge
#

You sub

alpine sable
spring kiln
shut temple
#

What the fuck happens here

#

+-

bleak ridge
#

Sus

zealous ruin
#

I guess it's a shorthand for "do it for both +inf and -inf", since the limits differ

#

For +inf it's +inf, for -inf it's 3/4

bleak ridge
#

Well wouldnt the limit not exist if it didnt approach the same value

zealous ruin
bleak ridge
#

I would imagine it would have to approach the same value cause its one limit

shut temple
#

It is 3/4 for both

#

No

#

I am dum

zealous ruin
#

It grows linearly when approaching -inf

shut temple
#

Oh tru

#

Sorry

wispy olive
#

Can someone explain why the answer is 3¹ + 3² + 3³ + 3⁴?

zealous ruin
#

3^n is the number of n-letter words

#

And n can only go up to 4

#

_ means that any letter can occupy this space
1-letter words have a form of _, 2-letter words _ _, and so on

#

For each _ underscore you can choose one of three characters

wispy olive
#

Why the 3^n series?

#

Why are we multiplying A, B and C?

zealous ruin
#

Let's create all one-letter words in this language:
A, B, C

#

Let's create all two-letter words in this language:
AA, AB, AC
BA, BB, BC
CA, CB, CC

wispy olive
#

Yes.

#

Why do we multiply the values?

zealous ruin
#

When creating 2-letter words, you fill each gap in _ _ with an arbitrary letter, A B or C. You can choose the 1st letter in one of 3 ways, same goes for the 2nd letter, they're independent

wispy olive
#

I see.

#

I know that.

zealous ruin
#

I assume that all operations in ~code~ are O(1) - then the function itself is O(1)

wispy olive
#

I want to know why they are raising A,B,C(3) to the power of something?

zealous ruin
wispy olive
#

Yeah.

zealous ruin
#

Which one?

wispy olive
#

1st.

zealous ruin
# wispy olive 1st.

Alright, let's create a language with a maximum of 4 letters, and the letters are {A,B,C,D,E,F} this time. How many 1-letter words can you create?

wispy olive
broken pine
#

uhhh geometry

broken pine
#

chapter 7

wispy olive
#

That fucking chapter made me quit that book.

broken pine
#

can ya help?

zealous ruin
broken pine
#

alright so thats a no for help right?

wispy olive
#

Another channel.

#

Channel busy.

broken pine
#

alright ty

zealous ruin
# wispy olive 6.

That's right. You have only one space for a letter, so you have 6 choices

wispy olive
zealous ruin
#

What if you had 2 letter words?

wispy olive
#

I see I see.

#

Let me see.

zealous ruin
#

Hint: 2-letter words in this language are just a concatenation of two 1-letter words

wispy olive
#

No wait.

#

Right?

zealous ruin
#

How did you arrive at that conclusion?

wispy olive
#

6 × 6.

#

Since 2 lettered.

zealous ruin
#

That's right

wispy olive
#

Ahaaaa.

zealous ruin
#

You choose a single letter arbitrarily (6 choices)

#

And then you choose another letter, arso arbitrarily, another 6 choices

wispy olive
#

Wow man you are awesome!

#

Are you a professional teacher or something?

zealous ruin
#

Not yet!

wispy olive
#

And sorry for being dumb and typos, it is 2:00 AM and I am sleepy lol.

zealous ruin
#

No worries

wispy olive
#

Well let us leave this channel cause within like 10 minutes 2 people wanted this place.

zealous ruin
#

disappears into a fine mist