#help-0

1 messages · Page 574 of 1

nimble elk
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thanks

pale basin
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@feral crag post the question

feral crag
#

@pale basin

pale basin
#

i dunno

feral crag
#

Oof

pale basin
#

if you look up some hyberbola equation

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perhaps it will have its equation defined in terms of asymptotes

distant bay
#

I’m confused

pale basin
#

@distant bay what x do you need to plug in f(x) to get the result 0, -12 etc etc?

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you calculate that

distant bay
#

Ok solve for x

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Basically

pale basin
#

@distant bay just plug in the inputs, and write your equation

distant bay
#

Okk

pale basin
#

for 17 too

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just plug it in for both f and g, write the equation

distant bay
#

I got -15 for a) 16?

pale basin
#

no, you dont plug in 0

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you plug in x

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@distant bay

distant bay
#

Ohhh

nimble elk
#

do I set this up as 8x+7x+90=180?

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nvm it mega wrong

muted raft
#

why do you think that is wrong?

lime valve
#

can someone help me?

uncut cosmos
#

what have you tried

viral owl
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i dont understand it

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too

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he goes at my class

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we're spanish

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and we don't understand it

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because the homework is in english

uncut cosmos
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alright

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you are have trouble understanding the question or trouble solving it?

viral owl
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both

lime valve
#

yeah

alpine sable
#

? help

uncut cosmos
#

ok so you've been given that the gray part has area 10 and that the line x is parallel

lime valve
#

no geometry

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and im 15 years old

uncut cosmos
#

The only thing required for solving this is area of triangles

lime valve
#

i know whats an area but no more

uncut cosmos
#

You know that right?

lime valve
uncut cosmos
#

you don't know area of triangle?

lime valve
#

no, sorry

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is it a x b

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like

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altura x base

uncut cosmos
#

it's 1/2 multiplied by base and hight

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height

lime valve
#

base is base and height is altura

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so yes

uncut cosmos
#

1/2 ab

lime valve
#

but what 1/2 means

uncut cosmos
#

Half of a multiplied by b

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I can send you solution but I think you should learn basic geometry first

alpine sable
#

help me please

uncut cosmos
#

Ask in unoccupied channels please

uncut cosmos
lime valve
#

like i know whats a perimeter, a polygon, a side, etc

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the problem is we haven't gave how to do this

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and i have to give my homework in 30 minutes

uncut cosmos
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that's maths

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wait lemme help

lime valve
#

if you can give me solutions and then explain @viral owl and me how to do it

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we would apreciate

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appreciate*

uncut cosmos
lime valve
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explain

uncut cosmos
#

Here b1=b2, so what will be the area of the rectangle?

lime valve
#

idk

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20?

ashen wave
#

Can anyone tell me everything I need to know about quadratic equations?

lime valve
#

IDK 😫

uncut cosmos
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It will be b1 multiplied by (h1+h2)

ashen wave
#

im really struggling with the quadratic unit

lime valve
#

is the answer 22

ashen wave
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especially the word problems

uncut cosmos
lime valve
#

knew it

#

ty

uncut cosmos
#

Area of gray part with be 1/2(h1+h2)*b1 = 10 so area will be 20

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C'mon dude lol you're just guessing

lime valve
#

yes

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but with luck

uncut cosmos
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Don't you wanna know the process

lime valve
#

i know 10 + 10 is 20

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so yeah 20cm

uncut cosmos
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cm²

lime valve
#

i dont know how to type that number

uncut cosmos
lime valve
#

but i know if we talk 'bout cm i think its with that 2

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the perimeter is the sum of all the numbers

alpine sable
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what is x^2 = -9

lime valve
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but there's no image

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theres no solution

alpine sable
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-3 right?

lime valve
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no

uncut cosmos
lime valve
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hard

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can't do it

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is it 1846

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?

uncut cosmos
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I can help you but not with the answer

lime valve
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can u help me at dm?

lime valve
uncut cosmos
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no

alpine sable
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Ok

lime valve
#

yeah

lime valve
uncut cosmos
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aight take the sides of the rectangles as a and b so the options for choosing three different sides with diffrent sums becomes a+2b and 2a+b

lime valve
#

what

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can u do images

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or paint

uncut cosmos
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There's nothing to show in the image

lime valve
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my english is not that good

uncut cosmos
#

length is a and breadth is b

lime valve
#

oh

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ok

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is it 56 or 42? i think i understand it(im not sure)

uncut cosmos
#

2a+b=40
2b+a=44

Find perimeter

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figure out yourself

lime valve
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84

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but why 2a+b is 40?

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i want to know

uncut cosmos
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cause you choose 3 sides right
two of them were breadths and one length

uncut cosmos
#

Yea ok

lime valve
#

ok

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another question

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i finished my homework, can u tell if something is wrong?(DONT SAY THE ANSWER, just say: 1 is wrong, and ill try to fix

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@uncut cosmos

uncut cosmos
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Alright

lime valve
uncut cosmos
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Dude this many questions 😐

lime valve
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10

uncut cosmos
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I've got stuff to do too y'know

lime valve
#

😦

uncut cosmos
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Tell me the one you're most doubtful of

lime valve
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there are 2

uncut cosmos
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Which ones

lime valve
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and this one

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hi?

uncut cosmos
uncut cosmos
# lime valve

You only need to fact that sum of all angles is 180 here figure rest on your own

lime valve
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then<??

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oh

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mmm

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let me guess

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please dont say it

uncut cosmos
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don't guess my man, solve em

lime valve
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like

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im solving it

uncut cosmos
#

Cool

lime valve
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i get 97

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and theres no 93 option

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97*

deep trellis
#

can someone help me with this?

lime valve
#

@uncut cosmos please help

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i have to give it

uncut cosmos
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Its correct

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11

lime valve
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oh

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the problem is the circle one

uncut cosmos
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The circle one is 4

lime valve
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i said 4.5 but no 4.5 option

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so 9/2

uncut cosmos
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although I don't completely understand the wording of that

lime valve
#

and this one?

lime valve
uncut cosmos
#

Ok

lime valve
#

NO LYERIFF

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WHY U LEAVE

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@uncut cosmos :(ç

uncut cosmos
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bro do I do all your homework

lime valve
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no

uncut cosmos
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Do these on your own

lime valve
#

just say if its right or wrong, and ill fix

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without you

uncut cosmos
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Ask your teacher after this

lime valve
#

😦

subtle seal
lime valve
subtle seal
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Can anyone help with this please? I tried evaluating it but to no avail

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channel taken?

real briar
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is that sc or what?

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and what goes to infinity?

azure idol
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how would i multiply 810 * 8/9?

lime valve
subtle seal
subtle seal
real briar
#

simplifty 810 by 9 so you get in total 90*8=720

azure idol
real briar
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he is trolling i think

lime valve
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sorry my bad

real briar
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are*

lime valve
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with another thing

real briar
lime valve
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no problem

subtle seal
subtle seal
azure idol
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so how would i

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?

real briar
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i just explained you mate

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you can write it as (810*8)/9

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simplify 810 by 9

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you get 90

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90*8 equals 720

azure idol
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oh sorry thanks

fallow laurel
#

Can you remember me the name of that rule?

uncut cosmos
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idt that has a name it's just basic equality

fallow laurel
#

so basicly, if I can do the same thing to both sides?

uncut cosmos
#

Yes

fallow laurel
#

Is this going to be sqrt?

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I think we're busy here

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in this channel lol

real briar
# subtle seal

i think you can rewrite this as (e^2/x-e^2/x+1)/1/x^2 which leds you to 0/0 so you can apply l'hopital

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like this

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you get an 0/0 case so you can apply l'hopital

ashen wave
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Is anyone here good at factoring?

mystic vigil
#

can i get help on a pls

alpine sable
alpine sable
# mystic vigil

you should investigte a bit about scale factors and trig in order to solve this

deep trellis
#

Can someone help me with this?

ionic jewel
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two right triangles

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14,21, center
10,2x-3, center

ionic jewel
deep trellis
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ok ty

wanton plinth
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I need assistance

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Im currently doing sine rule but have no idea what I am suppose to fine for these 2 questions

glass lichen
ionic jewel
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don't see how it's possible without that assumption

glass lichen
#

similar triangles if they're similar

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but i only see SA

ionic jewel
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they aren't similar

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SA?

glass lichen
#

side angle

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for similarity

ionic jewel
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you literally know two sides on both of them they can't be similar

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they share the same center line, but have different sides on the "24" part

glass lichen
#

the 2x-3 and 21 could be similar. . .?

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or am i smooth braining

ionic jewel
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nope

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it doesn't end up working out

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pretty sure

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one triangle ends up 14,14,21, and the other one is 14,10,2x-3

wanton plinth
ionic jewel
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with the words

rugged lynx
#

i need help on how to solve for x

glass lichen
rugged lynx
#

180 degrees?

glass lichen
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84 clearly isnt 180

rugged lynx
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i thought u said what do adjacent angles add up to

glass lichen
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No, I asked what you knew about the sizes of 84 and x-3, given they're opposite angles

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I never said add or sum

rugged lynx
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uh idk

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84 and x-3

glass lichen
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look in your notes then

rugged lynx
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i have no notes about it

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if i had notes i wouldnt be asking about it right now

glass lichen
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Ok well opposite angles are equal.

rugged lynx
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oh

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ok

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thanks

narrow vector
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can someone explain how to solve this

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log(-x)=2

glass lichen
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base 10?

narrow vector
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if base is missing it’s always 10?

glass lichen
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Im just making sure

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some notations have log meaning ln catshrug

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anyways -x=10^2

narrow vector
#

so -x=-100

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as final answer

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to find x

glass lichen
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yes, x=-100

narrow vector
#

thank you

pearl vortex
#

having trouble writing a power series as a 'regular function
such as representing the series from 0 to infinity of x^n being written as 1/(1-x)^2

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i have to find the power series of 1 to infinity of (n)(n-1)x^n

alpine sable
#

Send the question directly (as a screenshot) if possible

pearl vortex
#

here it is

alpine sable
#

anyone wanna help a brother out with some substitution *by parts

pearl vortex
#

@alpine sable is there a good first step I could take?

I recognize 1/(1-x) is a power series giving me x^n

ashen wave
#

Is anyone here good with quadratic equations?

shrewd oracle
#

i imagine many are

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just shoot with the q

tough tangle
#
What is the value of the IRA when you turn​ 65?```
#

help meh i suck at these things

ashen wave
shrewd oracle
#

just put in the question

ashen wave
#

alr

#

I need help finding out when/where an object hits the ground. here is the word problem- An object is launched directly upward at 64 feet feet per second (ft/s) from a platform 80 feet high. The path of the object can be modeled by the function h(t)=-16t^2+64t+80

shrewd oracle
#

physics class?

ashen wave
#

no this is just math but its high school math but im in middle school

shrewd oracle
#

i mean i ask cause i could approach this from how a physics student would

ashen wave
#

but- you need to factor to get the x-int

jagged imp
#

It hits the ground when it’s height is...?

shrewd oracle
#

so how far the object travels in the x-direction ya?

shrewd oracle
ashen wave
#

0

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yeah

jagged imp
#

I was trying to get them to answer lol

#

So set h(t)=0 and solve for t then

ashen wave
#

I did, isnt it 2?

jagged imp
#

Nope

ashen wave
#

uhm 5?

jagged imp
#

Ye

ashen wave
#

alright that clears things up but wait

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2 is the x value for the max right?

alpine sable
#

Write the equation of an exponential function that passes through the points 2, 48 5, 750

jagged imp
#

The max height?

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No.

ashen wave
#

yaya i love it when you actually know how to do math

shrewd oracle
ashen wave
#

yeah the max height of the object. (2,144)

jagged imp
#

Oh that’s what they were were asking

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You should have said t value lol

ashen wave
#

no I was asking for when it hits the ground

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where*

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actually wait it says - when/where the object hits the ground

jagged imp
#

It just hits the ground directly below where it was launched from right?

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It was launched vertically upwards

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So it’s not moving horizontally

ashen wave
#

uhm i think theres a bit of a slope after the vertex

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because these are parabola questions

shrewd oracle
ashen wave
#

yeahhh but this isnt physics xDD

jagged imp
#

Craby the parabola isn’t the shape of its motion

ashen wave
#

we would save that for another day xD

#

what??

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its the height and time tho

shrewd oracle
#

its the model for the height at a certain time

ashen wave
#

yeah

jagged imp
#

It’s it’s height against its time, the shape of its motion would be its height against its displacement in the horizontal direction

narrow vector
#

can someone help me out on a question if no one is getting help already

shrewd oracle
#

yeah so it has nothing to so with how the object is moving horizontally

ashen wave
#

oh

jagged imp
#

Assuming there’s no wind, if it was launched vertically upwards there’s nothing to make it move horizontally@ right?

ashen wave
#

Conor when we are talking about any X value we are talking about the time?

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or Y?

shrewd oracle
#

nt talking about x values whatsoever

ashen wave
#

y is usally height in my class

shrewd oracle
#

object is shot vertically in the +y direction

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assuming you set y as up

ashen wave
#

oh no im just asking in general

shrewd oracle
#

i mean, yeah in general the time would be used to help find the x diresction if it were a projectile that wasnt shot vertically

ashen wave
#

bc when I get the coordinates or the max height its (2,144) but does that mean the X is the time and y is the height

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so the 144 would be the height

shrewd oracle
#

no no theres no x here

ashen wave
#

ft

#

???

shrewd oracle
#

in your eq, your using t as your time

ashen wave
#

right

shrewd oracle
#

so h(t) is your height at some time

#

144?

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height of what

ashen wave
#

the height of the object

shrewd oracle
#

what max height?

ashen wave
#

The max height of the object is (2, 144)

shrewd oracle
#

yeah

ashen wave
#

but the Y axis is identified as height so would that mean at 144 that would be the height

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and 2 would be time

shrewd oracle
#

yeah

ashen wave
#

oh!

#

ok that helps thanks!

shrewd oracle
#

no bother

robust flame
#

Can someone help me with this?

shrewd oracle
#

okay so for this @robust flame, we will be using one of $sin(\theta) = \frac{O}{H}, cos(\theta) = \frac{A}{H}, tan(\theta) = \frac{O}{A}$

ocean sealBOT
#

Conor Sheridan

shrewd oracle
#

so we want to find the angle F, and we know 2 sides, we know the longest side which is known as the hypotenuse (or H), and also the adjacent side to F (or A) and this side is 12

#

so we want to use one of the formulas that have both H and A in it, if we look above we can see that $cos(\theta) = \frac{A}{H}$ uses both A and H, so now if we can find $\theta$ then we will have our angle F

ocean sealBOT
#

Conor Sheridan

alpine sable
#

HOW IS THIS

#

equal to

shrewd oracle
#

so to get the angle we then just use $\theta = cos^-1(\frac{A}{H})$

alpine sable
#

BRUH MOMENT

shrewd oracle
#

@alpine sable use other channel

#

please

ocean sealBOT
#

Conor Sheridan

robust flame
#

Okay thank you so much!

shrewd oracle
#

does any of it confuse you

robust flame
#

So I got 36.9

#

I would round that to 37 right?

glass lichen
#

,w calculate arccos(12/15) in degrees

shrewd oracle
#

depends on whether or not your asked to round it

robust flame
#

Yeah round to the nearest degree

glass lichen
#

so yes, 37 deg

shrewd oracle
#

yeah then you round up

robust flame
#

Ok thank you!!

deft scroll
#

isnt this video bullshit

#

i tried it on some other numbers but it didnt add up

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tried it on 50,802

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didnt work

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tried it on 120,467

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didnt work

glass lichen
#

cause 50802 isnt a cube number...

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it's clearly not going to work on an abritrary number

deft scroll
#

0_0

#

mhm

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yes i knew that

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for sure for sure

#

was just testing you clearly

shrewd oracle
#

lol

glass lichen
#

sure you were. . .

blazing rose
#

ok i got a which is the right choice

#

but idk how i got it really

#

like i did an educated guess

#

i knew that there was one rel max and 1 rel min because f'(x) goes from + to -, which means rel max at the point where it switches signs, and f'(x) goes from - to positive, which means rel min

#

but why is there 3 points of inflection

dusky moat
#

can someone help with part b

tight locust
#

no thank you

dusky moat
#

my initial attempt was f(x) = {1 if x is in Q and O, 0 if x is in I and O, and 0 if x is not in O}

#

but i'm pretty sure that would lead to discontinuities at any limit points of O

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this is 4.3.12 function it was mentioning

thorn kindle
#

1 if x in O, 0 otherwise?

#

don't see why you have to bother with Q and I

dusky moat
#

don't want it to be continuous on O

thorn kindle
#

it wouldn't

dusky moat
#

??

thorn kindle
#

it's 0 everywhere except O

dusky moat
#

yes but it would be continuous on all of O then..

#

O is an open set

spark ibex
#

Anybody good at elasticity of demand that could help me

shrewd oracle
#

just post the question regarding it

flat gust
alpine sable
# flat gust How

first find the length of a diagonal of the box, then you can make a second right triangle

flat gust
#

I don’t get it

alpine sable
#

can i have help on this pls

alpine sable
flat gust
#

Hm I see

#

So find the hypotenuse of with 80 and length 70

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Triangle

alpine sable
#

yeah

#

then to find the diagonal you look at the other right triangle

flat gust
#

Ya I see I just didn’t understand what the question was really asking because there are many lines from one corner to the other corner of the box

#

So which hypotenuse is it asking

alpine sable
flat gust
#

Oh really

alpine sable
#

if you go from one corner to the other

#

yeah

flat gust
#

So I just find one hypotenuse and that’s it

alpine sable
#

just find the length of one diagonal across the cube

flat gust
#

Ok

alpine sable
#

kinda like dat lol

tight locust
#

it can help if you think about it as using pythag twice

#

first use it to find the diagonal of the base of the box

#

then use the diagonal and the height to find the diagonal of the 3d shape

slender marten
#

You could also imagine one corner of the box is the origin in a three dimensional space then the other corner of interest just has the dimensions as coordinates then use the three dimensional Pythagorean theorem.

tight locust
#

sqrt(a^2+b^2+c^2) = sqrt(sqrt(a^2+b^2)+c^2) ?

#

huh?

slender marten
#

$d = \sqrt{x^2 + y^2 + z^2}$.

ocean sealBOT
#

stabulo

tight locust
#

oh nvm it checks out

#

i just forgot to square the base diagonal

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so it should be

#

sqrt(a^2+b^2+c^2) = sqrt(sqrt(a^2+b^2)^2+c^2)

slender marten
#

Something like this.

echo haven
#

Hi so I tried finding out what the hole was and I got an undefined number for the y

#

so what do I do if the y of the hole is undefined?

thorn kindle
#

holes are limits of the form 0/0

#

that means the numerator and the denominator have a common factor

#

factor the polynomials

echo haven
#

I did

slender marten
#

This question screams factorisation.

echo haven
#

I got 5(x-5) over (x-5)(x-5)

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cancel x-5 out

#

You get 5 as the x of the hole

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and when I plug it in I get 5/0

slender marten
#

Yeah, it appears there will be a vertical asymptote at x = 5.

echo haven
#

alr

#

ig I’ll just put no hole

thorn kindle
#

yeah that's right

#

there can't be a hole because there is no finite limit

echo haven
#

got it

#

ty

keen wasp
#

Does anybody understand the difference between finding volume by cross sections when the shape is perpendicular to x axis versus y axis

worthy verge
#

Sry channel taken ill delete

charred flint
#

@keen wasp you'd prefer it be perpendicular to the x-axis, otherwise you should convert it to x=... as a function of y, and integrate between y values

keen wasp
#

okay thanks

olive pewter
#

i’m really poor when it comes to square roots and derivatives qwq

#

how would i go about solving 5 sqrt x^3 ?

alpine sable
#

use power rule

#

to find the derivative

olive pewter
#

ONE SEC

#

aaAaaa

#

oki i’m a bit lost, n sqrt a power m becomes a power m/n

#

so i got to x ^ 3/5 and then 3/5x ^2/5

#

i’m not sure whether the 2/5 is negative or not KaaAAA

#

and then following that is ?

alpine sable
#

how to solve for missing side

#

yea

bold star
#

u can use

#

a^2+b^2=c^2

olive pewter
#

oh yee

#

there’s no angle lmao

alpine sable
#

so it would be

#

14.42

#

rounded 2 decimal places

bold star
#

not quite.

#

can you tell me what value is your a , b , and c?

#

if they are unknown say its unkonwn

alpine sable
#

2 legs

#

and hypo

#

would it be

bold star
#

yes

#

what would the values of a b c be

alpine sable
#

a is 8^2

#

b is unknown

#

c is 12^2

rocky sorrel
#

listen

#

use pythagorean

bold star
#

a is 8 and then a^2 is 8^2

#

@rocky sorrel yes but they mis identifing the legs and hypo when using pythagorean is not gonna help

#

@alpine sable yes so if you solve the the equation now, what do you get?

rocky sorrel
#

you know c is 12, b is undefined and a is 8. plug that into pythagorean, (a^2 + b^2 = c^2). so then you would get 8^2 + b^2 = 12^2. solve for b.

alpine sable
#

solving now

#

ok

#

80

#

so

#

4 5

celest void
#

Could someone help me with 4 and 5?

bold star
#

oh so what is b equal to? @alpine sable

celest void
#

I model it as a sinusoidal function right but i guess i need the phase shift?

#

$x=A\cos(\omega t + \phi)$

ocean sealBOT
#

Serena!

celest void
#

How am i getting the phi here which i guess is the phase shift?

alpine sable
#

@bold star 4 5

bold star
#

ur getting 45 for b? or 4.5

alpine sable
#

b is 80

#

but im squaring

#

idk the sign

#

but 4 5

bold star
#

u are squaring or square rooting?

alpine sable
#

root

bold star
#

i got 8.94 when i square root 80

rocky sorrel
#

@alpine sable

dire wren
#

does it ask for decimal? because usually i leave it as a simplified radical

slender marten
#

Oh no. Not decimals...

woeful pulsar
#

oh no

slender marten
#

$\sqrt{80} = \sqrt{(4)(20)} = \sqrt{(4)(4)(5)} = 4\sqrt{5}$.

ocean sealBOT
#

stabulo

slender marten
#

Please no decimals though.

rocky sorrel
#

thats if it asks for exact form

dire wren
#

90% it asks for that

rocky sorrel
#

true

dire wren
#

lol

slender marten
#

Unless it says otherwise, it's always exact form.

lament rock
#

i expanded the equation but i have no idea how to make the equation into a form including cos2ø

vale wigeon
#

i mean, you could factor cos^8(θ) - sin^8(θ)

#

into $(\cos^4(\theta) + \sin^4(\theta))(\cos^2(\theta) + \sin^2(\theta))(\cos^2(\theta) - \sin^2(\theta))$

ocean sealBOT
vale wigeon
#

and then observe that $$\cos^4(\theta) + \sin^4(\theta) = (\cos^2(\theta) + \sin^2(\theta))^2 - 2\cos^2(\theta)\sin^2(\theta) = 1 - \frac12 \sin^2(2\theta)$$

ocean sealBOT
vale wigeon
#

@lament rock

lament rock
lament rock
slim wolf
#

does anyone know discrete math

lament rock
#

nvm im just an idiot i needed to change ip cos2ø=-1/√3

wintry trench
#

need some help please

alpine sable
#

i have a question about physics, why does Fnet = Fg - Fk(the kinetic friction)?

#

Evaluate would be to find a decimal equivalent

#

I would personally show the intermediate log step as ur boxed answer

#

And than just write 2 under it or something

split fulcrum
#

Really not sure what I'm doing wrong here. Worked the problem out like 10 times and gotten the same answer every time.

jagged imp
#

you took the derivative of dy/dx wrt t, you need its derivative wrt x

#

so unfortunately its another application of chain rule

vale wigeon
slender marten
#

@split fulcrum This might help you.

#

To understand why imagine dy/dx = u(t) and x = x(t) then you're just doing the process again. Hence du/dx = (du/dt)/(dx/dt). Instead dy/dx = u. Giving you the formula in the screenshot.

#

Maybe you miss typed the power as 2 instead of 3?

craggy trellis
#

is it possible to get the slope with only x1 and y1?

slender marten
#

You mean with only one coordinate? If so, only if you have the equation of the curve.

chilly walrus
#

could someone help me with this?

#

and this

small stag
#

$$\begin{align*} \sin(\alpha) &= b \newline a &= \arcsin(b), a &= \pi - \arcsin(b) \end{align*}$$

hollow atlas
chilly walrus
#

I dont understand sorryu

#

ok

hollow atlas
#

i would advise remembering the unit circle

#

1 second

chilly walrus
#

yep ok

ocean sealBOT
#

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

chilly walrus
#

with the 4 quads

small stag
#

Bruh that doesn’t work???

#

But yeah par is right

hollow atlas
#

one thing u need to know before hand is

#

that x value is cosx

#

and y value is sinx

#

correct me if im wrong

chilly walrus
#

wait for what?

#

@hollow atlas

#

oh I see

#

ya

hollow atlas
#

1 / root(2)

#

can be written as ?

#

@chilly walrus

chilly walrus
#

root2/2

#

?

#

sorry

hollow atlas
#

correct!

chilly walrus
#

ya nah thats right

#

lol doubted

hollow atlas
#

so now u ask urself

#

where is the y value root2/2 ?

chilly walrus
#

pi 4

hollow atlas
#

from the range 0 to 2pi

#

bingo

#

where else?

chilly walrus
#

7pi 4

#

so its quad 1 and 4

#

?

hollow atlas
#

wrong

chilly walrus
#

oh 2

hollow atlas
#

i believe its 7pi/4 is -root2/2

chilly walrus
#

ah ok

#

1 and 2

hollow atlas
#

your second choice would be 3pi/4

chilly walrus
#

yep

hollow atlas
#

when it says 2pi

#

it basically means

#

the full circle

#

when it says pi its half of the circle

chilly walrus
#

ok

hollow atlas
#

do you understand how i got the solution or do you need further explanation?

#

there are many ways to rememebr the unit circle if your remember the [0, pi/2]

chilly walrus
#

wait so the answers are pi/4 and 3pi/4

#

i get that if so

hollow atlas
#

yes

#

all u have to rememebr is that x value is cos

#

and y value is sin

chilly walrus
#

what about 2nd question

#

What is the length of the arc on a circle with radius 6m, subtended by the angle π2 ?

#

yea I get that thanks!

#

could you give me a hand with the next? @hollow atlas

hollow atlas
#

yes i will try

#

give me one second been a WHILE since ive done calc

#

i promise this problem is very easy as well

chilly walrus
#

cool

#

just fyi

hollow atlas
#

its a simple formula memorization one if i believe

chilly walrus
#

i have 7 and a half minutes

#

yikes

#

mb

#

no worries if you cant figure it out by then, mainly want to understand

hollow atlas
#

i will get it no worries

chilly walrus
#

😎

hollow atlas
#

answer is 3pim

#

3 * pi * M

chilly walrus
#

?

#

this one?

#

i assume

#

yep

#

could you explain?

hollow atlas
#

formula is very simple arc length = radius * (angle in radians)

#

that is correct choice

#

i dont remember why the formula is that way off the type of my head, but make sure that when u do these problems

#

a common trick used by professors is that they give u degrees instead of radians

#

you will have to convert ur degrees in the radians

#

or remember the degrees version of this formula

chilly walrus
#

could you show your working?

#

ill understand it better I believe

hollow atlas
#

sure @chilly walrus

#

work for the example u did?

#

Ignore the banana

chilly walrus
#

ah i see

#

cheers for the help par ❤️ @hollow atlas

#

i like the nana

hollow atlas
#

thanks haha

#

anymore questions ? @chilly walrus

versed osprey
#

Could someone please check my question in #help-1

austere elk
undone copper
#

how to show two functions are orthogonal?

vale wigeon
#

in what context?

#

i could say "calculate their inner product and show that it's zero" but somehow i have big doubts that this would line up with the sense in which you are using the word "orthogonal".

undone copper
#

this is it

#

ty

vale wigeon
#

well if thats the formula for your inner product then yeah

undone copper
#

i dont really have a specified w from what i can tell

vale wigeon
#

.....

#

ok can you show the problem in its entirety

undone copper
#

its quite long

vale wigeon
#

okay

#

i've braced myself

undone copper
#

wiat

#

oh

vale wigeon
#

your weight function's right there lul

undone copper
#

oof

#

im a dumbass

#

tyvm

vale wigeon
#

use properties of the dot product

jagged imp
#

Yes, also a.a=||a||^2

vale wigeon
#

yup those

alpine sable
#

The mean age of male and female were 28.86 ± 11.27 years and 25.31 ± 7.70 years respectively
i thought mean gives us only one result
so why is there this plus minus part?

vivid kayak
#

What would a graph look like if it was growing exponentially at a fixed rate?

tardy timber
#

not sure what you mean

#

like a^x

#

?

vivid kayak
#

i)

#

Because I know that it should pass through (0,1)

#

but im not so sure if its changed to (0,100000)

#

what do you think?

tardy timber
#

oh okay, so notice on the log scale network F is fairly linear

#

which indicates exponential growth with fixed rate

vagrant rover
#

Can someone check if this question is written wrong? I don't think there is an actual answer here. I don't really want to know the answer, I just want to know if the question is written incorrectly or not. I had a problem with questions being written wrong last year and my math teacher isn't responding to my emails.

quaint trout
#

The answers are fine

tardy timber
#

yeah

#

they seem fine

quaint trout
#

What they mean is not that the expressions are written as a^2 - b^2, but that the expressions are of the factorized form of a difference of squares

#

So what does a^2 - b^2 looks like factorized? And which one doesn't look like that

vagrant rover
#

🤔

#

Interesting

vivid kayak
#

and for ii) like what proportion? per day or overall?

vagrant rover
#

Alright, I'll look over it again. Thanks guys.

vivid kayak
#

nvm network w is growing constantly every 5 days at the same rate

#

so its slower

tardy timber
#

yeah F is exponential whereas W is linear

#

so F grows faster

vivid kayak
#

ty

#

ok jesus

#

iii) lol

#

I just need to clarify that the W is indeed the decimals

#

cause then it makes this alot easier

tardy timber
#

huh?

#

I dont see iii

vivid kayak
#

oof wait

#

theres like 3 of these

#

and they all follow the same thing

tardy timber
#

okay plug in t and F into the equation

#

ln(F) = number -> F = e^(number) right?

vivid kayak
#

I just want to be sure F is the decimals

#

cause then it makes this alot easier

tardy timber
#

F is the decimals?

#

idk what you mean by that

vivid kayak
#

F=11.65...

tardy timber
#

yeah

vivid kayak
#

yea ty

tardy timber
#

well ln(F)

#

you need to get it into F

#

so e^(11.65...)

vivid kayak
#

wait what

#

so i can't put it simply as 11.65?

tardy timber
#

no

#

you are given that ln(F) = number

#

so to find F, you need to take base e on both sides

vivid kayak
#

So if I do e^11.65

#

thats essentially F

#

right?

brave cairn
#

is this true?

slender marten
#

Definitely not.

brave cairn
#

hmm

vale wigeon
#

$\sqrt{a+b} \neq \sqrt{a}+\sqrt{b}$

ocean sealBOT
vale wigeon
#

every time you write $\sqrt{a+b}$ as $\sqrt{a}+\sqrt{b}$ a puppy dies

ocean sealBOT
brave cairn
#

ooooh damn I forgot that

slender marten
#

No puppies left.

brave cairn
#

so...this term cannot get any more simplified?

slender marten
#

I'd say that is the simplification.

vale wigeon
#

this isnt a term this is an equation

#

and without context yeah you cant rly say much else

vagrant rover
#

So if you substitute 2 in for x then you get -48 for the given example equation. And then B also gives -48 when you substitute 2 for x. Thus, B is correct here, right?

vivid kayak
#

no

vale wigeon
#

no

vivid kayak
#

Try doing it again

#

but leave the neg

#

until the last step

vale wigeon
#

just because two expressions have the same value at x=2 does not by itself mean theyre equivalent

#

if they had DIFFERENT values at x=2 you could conclude they arent the same

vivid kayak
#

Wait B is correct

vagrant rover
#

K, i'm confuzelled

vivid kayak
#

B is correct

#

Just do the simplification

vagrant rover
#

Yeah I did

vivid kayak
#

but leave the negative symbol until the last step

vivid kayak
#

have you subbed 2 into every other eqn?

vagrant rover
#

Yeah, they all come out wrong

vale wigeon
#

this means that the value of (B) at x=2 is -48

#

nothing more

#

honestly like

vivid kayak
#

if you have a different answer every time that isn't the same as your bracketed eqn

vagrant rover
#

Oh

vivid kayak
#

then b is correct

vagrant rover
#

Let me try with a different number

vale wigeon
#

is there anything stopping you from actually doing an honest to goodness expansion

#

like

vivid kayak
#

slap

vale wigeon
#

it sounds like youre trying to avoid that

#

fsr

#

why

vivid kayak
#

i mean

vagrant rover
#

What do you mean?

vivid kayak
#

its one way

#

but its a long way

#

just expand

vagrant rover
#

I don't udnerstand what's happening

vivid kayak
#

its the easiest thing

vagrant rover
#

What does expand mean

vivid kayak
#

bruh

#

Expand the eqn

#

so you end up with one of the 4 choices

noble sinew
# vagrant rover But what does this mean?

Imagine if 1 equation was (2x^2) and another was (2x^5). Setting x=0 gets the same value for both 2x^2 and 2x^5 yet 2x^2 is obv not the same as 2x^5. Setting x=1 we also get the same value from both.

vagrant rover
#

Oh

#

So it still could not be B?

#

I see what you mean

noble sinew
#

If the others didn't give the same value then you can conclude by process of elimination

#

but otherwise just expand the equation

undone copper
#

trying to find eigenvalues/function for x(1)=0 , x(2)=0 bcs

vale wigeon
#

youre trying to find the values of lambda which make this BVP have nontrivial solutions?

#

do you want the long formal version or the short hacky version

undone copper
#

idm

#

usually bcs have like an x(0)

vale wigeon
#

your nontrivial solutions will be sinusoids that vanish at t=1 and t=2

#

so accordingly, you'll have $\lambda_k = -k^2 \pi^2$ i think? i might be a little off

ocean sealBOT
vagrant rover
#

I'm getting 4.472135955 when solving the equation, but that is not a possible answer. Am I doing it wrong?

gray isle
#

not an equation, also how are you getting that value?

vagrant rover
#

I mean expression

gray isle
#

you're not putting your parentheses in the correct locations

#

also
hint: you should do this without the aid of a calculator

#

the square root radical is being applied the the 6s ONLY

#

$\sqrt{a} \pm b \neq \sqrt{a \pm b}$

ocean sealBOT
#

ℝamonov

vagrant rover
#

That's confusing

#

Ohhh

#

Ohhhh, okay. I didn't know that.

#

Awesome, thanks!

#

-10

fallow igloo
#

How is this supposed to be done?

#

@vale wigeon

vale wigeon
#

$\bd{u} \cdot \bd{v} = \nrm{\bd{u} } \nrm{ \bd{v}} \cos(\theta) \ \nrm{\bd{u} \times \bd{v}} = \nrm{\bd{u} } \nrm{ \bd{v}} \sin(\theta)$ \ where $\theta$ is the angle between $\bd{u}$ and $\bd{v}$

ocean sealBOT
fallow igloo
#

but i dont know the angle between those, do i?

vale wigeon
#

you dont need theta itself

#

consider: $(\bd{u} \cdot \bd{v})^2 + \nrm{\bd{u} \times \bd{v}}^2 = \nrm{\bd{u}}^2 \nrm{\bd{v}}^2$

ocean sealBOT
fallow igloo
#

so it has to be 6

#

thanks again :D

vagrant rover
#

Can someone explain this question to me? Does it want an answer that does not look like this: x^2-y^2

#

What does it mean by "the difference of two squares"

shell widget
#

Yes

vagrant rover
#

Ah okay

#

Ty

shell widget
#

It wants you to find out an expression which is not of the form x^2 - y^2

#

btw

#

x^2 - y^2 = (x-y)(x+y)

#

so try to look for an expression which is not of the form (x-y)(x+y)

vagrant rover
#

Interesting, interesting. Ty!

shell widget
#

np

vagrant rover
#

B, right? Just by looking at it. Both sides are being subracted.

#

@shell widget

#

Or should I dip deeper?

#

I'm just gonna dig deeper

shell widget
#

not sure tbh, question is kinda weird. (81 - x^2) itself is difference of two squares

vagrant rover
#

Yeah, I'm not understanding how it's supposed to be solved.

shell widget
#

im thinking it's A

#

because (4x^2 - 36) can be written as [(2x)^2 - (6)^2] which is the difference of two squares

#

But (36 + 4y^2) is not the difference of two squares

shell widget
#

In B, we have difference of two squares two times

#

xd

vagrant rover
#

xd

shell widget
#

Ok no problem, let me explain

#

For option B

vagrant rover
#

Right

shell widget
#

We have (81 - x^2) (81 - x^2)

vagrant rover
#

Yes

shell widget
#

Which is [(9)^2 - (x)^2] [(9)^2 - (x)^2]

#

Yes?

vagrant rover
#

Yup

shell widget
#

Now as you can see, we have something of the form x^2 - y^2 two times

#

so we do have the difference of two squares

#

Two times here

vagrant rover
#

Oh

#

Wait so x^2 - x^2 is also not what we're looking for?

#

Okay okay, I got unnecessarily confused.

shell widget
#

x^2 - y^2*

#

we are looking for an expression that can not be written as x^2 - y^2

gray isle
#

as written both A and B are valid options

vagrant rover
#

So the question is written wrong?

shell widget
#

I know ramonov, but I think they want us to see that 36 + 4y^2 isn't difference of two squares

gray isle
#

it feels like the y in A should be an x or vice versa

shell widget
#

yeah

#

part c and d are both difference of squares

#

so it's definitely A i think

rich basin
#

I need help understanding getting the tangent at a point of a function

shell widget
#

since B is also correct

#

try another channel

vagrant rover
#

One second, let me review what you guys just said

gray isle
#

if

it feels like the y in A should be an x or vice versa
then the answer would be B only.
B is a square

vagrant rover
#

Can't we just write (36 + 4y^2) as: (18^2+ 4y^2)

shell widget
#

but difference of two squares is being applied

#

no?

#

2 times

gray isle
#

it seems the goal of the question is to identify the factorisation of a difference of two squares
a^2 - b^2 = (a-b)(a+b)

shell widget
#

how is 18^2 = 36?

vagrant rover
#

Oh wait nvm nvm nvm

#

Ignroe that

#

Just ignore that

gray isle
#

a^2 - b^2 = (a-b)(b+a)
would also be valid

vagrant rover
#

So then only B is correct?

gray isle
#

assuming they made a typo with A, yes

vagrant rover
#

What type would they have made?

#

typo

gray isle
#

the question would more sense if option A was something like:
$$(4x^2-36)(36 + 4x^2)$$
or
$$(4y^2-36)(36 + 4y^2)$$

ocean sealBOT
#

ℝamonov

vagrant rover
#

I mean

#

That would still

gray isle
#

a^2 - b^2 = (a-b)(b+a)
would also be valid
since a+b = b+a

vagrant rover
#

Yeah but wouldn't the correct answer have to have either (a-b)(b-a) or (a+b)(b+a) in order to not be written as the difference of two squares?

#

I'm sorry if I'm confused

gray isle
#

if the suspected typo was fixed, A would be a difference of two squares

#

leaving B as the only correct answer

#

(since B isn't not a difference of two squares)

vagrant rover
#

Right, but the current answer of A is also not a difference of two squares, yeah?

gray isle
#

yes

vagrant rover
#

Because the question could be written incorrectly, it wouldn't be the first time

#

Alright. I'll email the principle

#

THanks

gray isle
#

,w expand (4x^2-36)(36+4y^2)

gray isle
#

,w expand (4x^2-36)(36+4x^2)

vagrant rover
gray isle
#

yes

vagrant rover
#

Oh right, you can rewrite 1296

#

Gottchu

#

Awesome, thank you so so so mcuh!

gray isle
#

and for B,
individually (81 - x^2) is a difference of two squares,
however (81 - x^2)(81 - x^2) is not

vagrant rover
#

I see. I'm glad I actually understand now

#

Ty!

#

❤️

marsh wren
#

is it correctly understood that if i have $QRx=y$ and $Q$ is orthogonal, then i can rewrite it as $Rx=Q^Ty$?

ocean sealBOT
#

iBoughtWinrar

vale wigeon
#

yes, by multiplying both sides by Q^T