#help-0

1 messages · Page 759 of 1

alpine sable
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wait so this one is

ionic jewel
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is?

alpine sable
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8a -5b -5c

ionic jewel
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yes

alpine sable
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right?

ionic jewel
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yes

alpine sable
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okay ty

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so three terms

ionic jewel
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yes

alpine sable
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ty

sacred otter
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Anyone can please help me to solve This? I can't seem to wrap my head around the first move, if I can get the first move, the rest will follow. But I'm stuck

alpine sable
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what's the question?

sacred otter
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Find the sides

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How did I get this sticker?

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Anyway, find the sides of the big triangle

alpine sable
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i think this can be solved with trig

sacred otter
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Yea, just what's the first step. Maybe I'm exhausted and can't see it

alpine sable
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I will look at it, give me some time

sacred otter
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👍

alpine sable
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you can use sin

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sin(20) = 425/hyp
sin(20) * hyp = 425
hyp = 425 / sin(20)

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,w calc 425 / sin(20)

alpine sable
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425^2 + b^2 = 1424^2

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180625 + b^2 = 2027776

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b^2 = 1847151

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b = 429.784829886

sacred otter
alpine sable
alpine sable
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a^2 + 675^2 = 429^2

alpine sable
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well

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u know this this then

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u can also get the hypotenuse of the small triangle with sah coh tao whatever its called

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tan(20) = mod/hos

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tan(20) = 425/hos
tan(20) * hos = 425
hos = 425 / tan(20)

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,w 425 / tan(20)

alpine sable
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a^2 + 675^2 = 1167^2

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a^2 + 455625 = 1361889
a^2 = 906264

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,w sqrt(906264)

alpine sable
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DONE

sacred otter
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k

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Thx

tight locust
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K

alpine sable
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it doesn't really look correct that the side is 951 lol

tight locust
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anyone else need help i'm slightly bored.

compact coral
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😭

alpine sable
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but i think it's correct

oak chasm
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The triangle you're using it in isn't a right triangle.

alpine sable
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Yh I was wondering as well

oak chasm
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@sacred otter The two angles in the bottom middle add up to a straight line, or 180°. So, mark the left one A and the right one 180° - A. Mark the far right angle as B. Mark the top angle next to 20° as 180° - 90° - A = 90° - A . Mark the segment between A and the right angle as x. Mark the right side of the large triangle as y.

Now, the sum of the angles is the right triangle is 180°, so 20° + (180° - A) + B = 180°, so B = 180° - 20° - (180° - A) = A - 20°.

Now, we can use law of sines:

sin(A)/675 = sin(90° - A)/x = cos(A)/x
tan(A) = 675/x

sin(A - 20°)/675 = sin(90° - A + 20°)/(x + 42.5) = cos(A - 20°)/(x + 42.5)
tan(A - 20°) = 675/(x + 42.5)
(tan(A) - tan(20°))/(1 + tan(A)tan(20°)) = 675/(x + 42.5)

Now, we know from earlier that tan(A) = 675/x, so we fill that in:

(675/x - tan(20°))/(1 + 675/x tan(20°)) = 675/(x + 42.5)

Now you have x and a bunch of constants.

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That should get you started.

tight locust
oak chasm
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Then you can use the Pythagorean theorem once you have x.

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That will get you the other two sides.

alpine sable
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what did i do wrong @oak chasm

oak chasm
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@alpine sable Your tangent = side ratio thing was wrong, since you have a non-right triangle you're doing it in.

alpine sable
oak chasm
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20° isn't one of the angles of one of the right triangles.

alpine sable
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you mean this calculation?

oak chasm
alpine sable
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sin(20) = 425/hyp
sin(20) * hyp = 425
hyp = 425 / sin(20)

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this?

alpine sable
oak chasm
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Yes, the 20° isn't part of a right triangle.

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The angle to the left of it is part of the small right triangle.

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The angle to the left of it plus the 20° is part of the large right triangle.

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But the 20° itself isn't part of a right triangle.

alpine sable
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oh well forget it then

analog nymph
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question resolved*

alpine sable
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is this the same thing as

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6/5x

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because the numerical coefficient is 6/5 so couldn't the variable go anywhere?

limpid spade
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NOOO

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caps

alpine sable
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:0

limpid spade
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(6x)/5 is the same as (6/5)*x

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6/(5x) would be (6/5)*1/x

alpine sable
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ohh

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okie

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ty

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but the numerical coeffiuevciitn for that question is 6x/5 right?

limpid spade
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?

alpine sable
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*coefficient

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i mean 6/5

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sorry

limpid spade
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what's the question

alpine sable
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this

limpid spade
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:/

alpine sable
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the numerical coefficient

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is it 6/5

limpid spade
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yes

alpine sable
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ty

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the answer key says these are equivilant

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can someone pls explain how these are equvilant

limpid spade
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they're just rearranged

tight locust
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a-b+c = c-b+a

jade birch
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commutative property

tight locust
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this is called the commutative property of addition.

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A+B = B+A

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this is true in all fields

alpine sable
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okie

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but what about the variables

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and the powers

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what do you do with those

glass lichen
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$a+b+c=c+b+a$

ocean sealBOT
alpine sable
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like in here

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what do you do with the x and ^2

glass lichen
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they're part of the "a"

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cause it's all one term...

alpine sable
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okie ty

agile crescent
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hey guys just wondering if someone could tell me if this is right?

glass lichen
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that's the reciprocal identity of tan

agile crescent
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thanks

keen crane
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lim of cos(1/x) as x->0, why is it undefined?

tight locust
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ok

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let u = 1/x

tawny condor
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ABCD is a square.
FD = 2CF
BE = CF

a) Find DG/CF (I found that it is 6)
b) Show that AHFD can be blocked inside a circle (done)
c) Find angle DHF (I need help with this)

tight locust
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then x = 1/u. so you are taking the lim as u goes to inf

tawny condor
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Can somebody help me with this?

tight locust
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and cos(inf) is not a well defined expression

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the most you can say about it is that it is between -1 and 1

tight locust
tawny condor
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yeah

tight locust
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Do you have any exact measurements?

tawny condor
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Nope

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You can calculate angle AGB though

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with inverse tan in triangle AGB or DGF

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atan(1/3) which is 18.43494882

keen crane
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wouldnt there still be an answer, because it still approaches a number, its just that there would be a hole there

tight locust
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no it does not approach a number

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cos(1/0) = cos(inf)

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there is no such thing as cos(inf)

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it literally does not converge to a value

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,calc cos(1/(0.1))

ocean sealBOT
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Result:

-0.83907152907645
tight locust
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,calc cos(1/(0.01))

ocean sealBOT
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Result:

0.86231887228768
tight locust
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,calc cos(1/(0.001))

ocean sealBOT
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Result:

0.5623790762907
tight locust
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,calc cos(1/(0.00001))

ocean sealBOT
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Result:

-0.99936080743769
tawny condor
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can I get some help aswell

tight locust
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what exactly are you having trouble with proving?

tawny condor
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finding angle DHF

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c) Find angle DHF (I need help with this)

carmine notch
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Whats the difference between round brackets and square brackets when determining domain and range

tawny condor
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square brackets is including the number, parenthesis are not including

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so [0, 3) will be from 0 to 3, including 0 but not including 3 (there is a hole at 3)

carmine notch
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like a whole where the coordinates are located?

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hole*

tawny condor
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yes

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not including that specific number

carmine notch
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alright thanks

tight locust
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@tawny condor you said that AHFD is cyclic, correct?

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whew this was a tricky one but i found the answer

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or what exactly did you mean by "blocked inside a circle?"

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,w arctan(2/3)

alpine sable
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what is cos 😭

sand jetty
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uh

alpine sable
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are those just variables put together?

sand jetty
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thats a long one, sure you have to do this exercise and you didn't learn what cosine is?

tawny condor
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Oh

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wait

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I seeeeee

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that's actually very simple

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ty

tight locust
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@tawny condor

tawny condor
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yes I got it already

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:D

tight locust
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yeah just explaining how

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it's tricky if you don't know the cyclic quadrilateral theorems

tawny condor
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yeah dw I remember that rule

alpine sable
tawny condor
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I know everything unfortunately

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tysm

alpine sable
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k imma just try smth and see how it goes lol

tawny condor
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@alpine sable you aren't supposed to know that at all then

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have u learned trigonometry?

alpine sable
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that were variables put together

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idk

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it just says this

tawny condor
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Oh

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why would they put cosine there lmao

alpine sable
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lmaooo

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what even is cosine 😭😭

tight locust
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the question is whether f(x) = cos(x) + x is a polynomial

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which it is not

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well it sort of is but not really. infinite polynomials are not polynomials

alpine sable
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me = confusion

tight locust
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don't worry about it. a polynomial is just something that looks like this:

alpine sable
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hehe

tight locust
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$\sum\limits_{k=0}^n a_kx^k = a_0x^0 + a_1x^1 + a_2x^2 + ... + a_nx^n$

tawny condor
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why would u use sigma

limpid spade
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pretty sure they didn't see sum

alpine sable
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daveie

ocean sealBOT
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EndTimes

limpid spade
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Dave is in 7th grade

tight locust
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where the sequence $a_k$ are the coefficients of the powers of x

ocean sealBOT
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EndTimes

limpid spade
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I mean strawberry

tight locust
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sigma notation is very easy. i can teach you how to use it if you want

limpid spade
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teach they integrals afterwards 😂

tight locust
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well if you insist. reimann sums are not too difficult to explain

limpid spade
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and u can end with topology

tight locust
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klein bottle

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WOAH

limpid spade
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and if they want a little challenge

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u can teach them Inter-Universal Teichmuller Theory or Prime Dimensional Matrices

alpine sable
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can anyone confirm the last one? pls

vague coral
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it's possible tho

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this function is bijective

alpine sable
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that's not injective, clearly there are several x's for the same y

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oh wait

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miss read n with 1 right away

vague coral
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f(n) = n/2 if n is even
f(n) = -(n+1)/2 if n is odd

alpine sable
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sorry

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interesting

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very nice

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thanks!

vague coral
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np

ocean sealBOT
alpine sable
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wdym?

ocean sealBOT
alpine sable
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it can

vague coral
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what are u talking about

alpine sable
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but ye xd

glass lichen
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post the question

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and dont ping helpers right away

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Ok.. also it's very unclear what's in what

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secsecx-tanx for example

somber osprey
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Mathematics

alpine sable
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@everyone

somber osprey
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Lol

knotty sierra
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how do we do b bit?
n/4
is used to find lower quartile
but the number are starting from 150
so i did 190-150
which is 40
40/4
=10
150+10=160
and 160 is included in 150<h<=160
but the answer key says thats wrong
please tell me where i made a error

west tartan
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Help, I need to know what X is. And I need to understand how you got it because I need to transfer that into JS for a project I'm working on.

thorn kindle
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3.67X + X = X(3.67+1) = 4.67*X

west tartan
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ok hold on i messed something up here

thorn kindle
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Oh really?

west tartan
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8720=(X*0.0367)+X

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the final number is the sum of the unknown number plus 3.67% of the unknown number

thorn vortex
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$8720 = X(0.0367 +1) \implies 8720 = X(1.0367)$

west tartan
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It just defines x as 1?

thorn kindle
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You are getting your numbers mixed up.

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Is it 0.037 or is it 3.67%?

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Those values are different

west tartan
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its 3.67%. i thought i could write 3.67% as 0.0367. is this incorrect?

thorn vortex
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you wrote 0.037 instead

thorn kindle
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Yes that is correct. But 3.67% is NOT 0.037

ocean sealBOT
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Pealover

west tartan
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Am i stupid lol, 1 is 100% 0.1 is 10% 0.01 is 1% correct?

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oh no

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i am stupid ok, ok i see

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hold on

west tartan
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3.67%

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im sorry

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i misunderstood his question

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8720=(X*0.0367)+X is the final question i need help with.

thorn kindle
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0.0367X + X = X(0.0367+1) = 1.0367*X

west tartan
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Wait what did you do here? 0.0367X + X = X(0.0367+1)......how did you getX(0.0367+1)

thorn vortex
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factorization

thorn kindle
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This is called the "distributive property"

thorn vortex
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$ab + ac = a(b + c)$

ocean sealBOT
#

Pealover

west tartan
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Where did the 1 come from

thorn kindle
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X/X=1

thorn vortex
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because $X/X = 1$

ocean sealBOT
#

Pealover

west tartan
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so we are left with 8720 = 1.0367*X

thorn vortex
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yes

west tartan
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so divide both sides by 1.0367?

thorn vortex
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exactly

west tartan
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OH MY GOD

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i knew it had to deal with 100%+ but i lost my train of thought and couldnt get it back thank you so much

thorn vortex
#

np

remote lodge
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haven't done this in a while, so without giving me the answer how do i do this?

jagged imp
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try write sqrt(32) in terms of sqrt(2) so you can combine the two terms. if you need guidance on how to do that say it

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if its the rationality part you're struggling with then say that

remote lodge
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I just forgot how to simplify bleak

thorn vortex
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try to split the number into product of prime numbers

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@remote lodge

remote lodge
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Yeah that's what i was thinking

proud estuary
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How would I work this out, not the answer, just how do I work it? One bag of fertilizer will cover 1,225 ft2 of lawn. A front lawn is approximately 115 ft by 100 ft, and the back yard is approximately 130 ft by 100 ft. How many bags of fertilizer will be needed to fertilize both the front and back yards

surreal meadow
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you are given a few key pieces of information:
how much area a bag can fill
the side lengths of one of the areas
the side lengths of the other area

proud estuary
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yes that I understand but what do I do with it, I have not had to do this yet?

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do I add? divide what?

surreal meadow
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think about it for a second

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you know how much each bag can fill

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so the first thing we want to find

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is how much area we are looking to fill up

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how would you go about that?

proud estuary
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I don't know this is why I am asking

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not sure how to find it

surreal meadow
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How many bags of fertilizer will be needed to fertilize both the front and back yards

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reading that^

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what are we tring to fertilize?

proud estuary
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the front and back yard

surreal meadow
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right, so it follows that we want to find out the areas of the front and back yards

proud estuary
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so how do I find the areas?

surreal meadow
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read the question and find the information given

A front lawn is approximately 115 ft by 100 ft, and the back yard is approximately 130 ft by 100 ft.

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it's safe to assume these are rectangular areas

proud estuary
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not sure where your going

surreal meadow
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do you know how to find the area of a rectangle?

proud estuary
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no

surreal meadow
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i'm assuming you're in algebra 1?

proud estuary
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yes but Ineed to undertand can you tell me the steps I need to take?

surreal meadow
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yes

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the question asked us "How many bags of fertilizer to fertilize both the front and back yards"

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so our solving process is as follows:

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  1. find out the total area we want to fertilize
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1a. this is composed of the front and back yards, so we must find the area of both of those

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1b. sum up those areas

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  1. create an equation that tells us how much area X bags will give us
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  1. solve that equation when the area we want to fill is equal to that of the front and back yards together
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so let's look at point 1.

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the front and back yards are rectangular, so to find their areas we need to do length * width

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A front lawn is approximately 115 ft by 100 ft
the length is 115ft, and the width is 100ft. @proud estuary what is the area?

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its not 11 everywhere

proud estuary
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11,500

surreal meadow
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these comments are a little disruptive

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😐

surreal meadow
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in this case: 11500 ft^2

thorn vortex
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yes

surreal meadow
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alright now @proud estuary do you think you can find the area of the back yard?

proud estuary
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13,000

surreal meadow
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this is disruptive

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can you not @dense scaffold

surreal meadow
surreal meadow
proud estuary
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24,500

surreal meadow
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great

surreal meadow
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how much area can we fertilize with 1 bag?

proud estuary
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1225

surreal meadow
proud estuary
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2450

surreal meadow
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yup, so i think you understand how that works

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so we can say that X bags will fill up an area of 1225 * x ft^2

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so we create a function A(x) = 1225x

gray isle
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<@&268886789983436800>

surreal meadow
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which tells us the area fertilized by x bags

surreal meadow
proud estuary
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@surreal meadow thank you so much I got it, it is 20 bags

surreal meadow
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awesome 🙂

proud estuary
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Got time for one more?

surreal meadow
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yes i do

proud estuary
#

A commercial airline plane with 250 passengers on a 3250 km flight from Seattle to Detroit averaged 650 kilometers per hour and used fuel at a rate of 5000 liters per hour? What is the fuel consumption in gallons per passenger (gal/passenger)

surreal meadow
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thank you @ namington

surreal meadow
proud estuary
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5000 liters

surreal meadow
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great

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and how long is the flight?

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or the distance that is

proud estuary
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3250km

surreal meadow
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ok so you understood the info given. let's move forward

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we know that the plane travels at 650 km/h

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and the flight is 3250km long

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so how many hours will it take for the plane to get to its destination?

proud estuary
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5hr?

surreal meadow
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yup

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so how much fuel will the plane use up?

remote lodge
surreal meadow
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(given that it uses 5000 liters per hour)

proud estuary
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25000?

surreal meadow
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exactly

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so now we want to find the final ratio, gallons/passangers

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can you write a ratio of liters/passanger from what we've solved so far?

proud estuary
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this part I do not understand

surreal meadow
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alright, so the question is asking us for the fuel consumption per passenger

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and we know the following: 25000 liters of fuel were used up to transfer 250 passengers

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so the ratio of fuel (in liters) to passengers is 25000:250 or $\frac{25000}{250}$

ocean sealBOT
#

maximo

surreal meadow
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does that make sense/look familiar?

proud estuary
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no sorry it does not

surreal meadow
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let's think of it the other way around then

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250 passengers traveled with 25000 liters of fuel

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so 250 passengers used up 25000 fuel, how much fuel did each passenger use up?

proud estuary
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this is likely wrong but 1 gallon?

surreal meadow
#

let me ask a different question, if 2 people ate 10 apples, how many apples did each person eat? (assuming the apples are distributed equally among the people)

proud estuary
#

5

surreal meadow
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right

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so now instead i'll ask

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2 people used up 10 liters of fuel

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how much fuel did each person use?

proud estuary
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5

surreal meadow
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perfect

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now let's use bigger numbers

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25000 liters of fuel were used for 250 passengers

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how many liters were used for each passenger?

proud estuary
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100

surreal meadow
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yeah

remote lodge
surreal meadow
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so the fuel consumption in liters per passenger is 100 liters/1 passenger

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did that make sense?

proud estuary
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no

surreal meadow
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what about it didn't make sense?

proud estuary
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nvm it did I read it wrong

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so the answer is 100

surreal meadow
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not quite

proud estuary
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ohhh

surreal meadow
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we now have a fuel consumption in liters/passenger

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but we want gallons/passenger

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do you happen to know the conversion rate of liters->gallons?

proud estuary
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no

surreal meadow
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yeah same here, but i'm assuming the question provided it

remote lodge
surreal meadow
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^ that right there is a good starting point

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we know that 1 gallon = 3.78541 liters

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so how many gallons are in 100 liters?

proud estuary
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26.4172

surreal meadow
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looks about right

proud estuary
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so the answer is 26.4

surreal meadow
#

26.4 gallons/passenger

proud estuary
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@surreal meadow I wanted to say thank you, your a life saver, I would not have figured these out without your help, you are very appreciated.

surreal meadow
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here to help catthumbsup

remote lodge
alpine sable
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how can I solve this?

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plz

placid zinc
#

Might be easier to figure out what volume the tetrahedron doesn't take up

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Realize there's 4 of the exact same "missing volume"

alpine sable
#

yeah but how do I do that?

placid zinc
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Can you find the length of any of the sides of the tetrahedron?

alpine sable
#

1st Diagonals of the square. 2nd sides of the square. 3rd Angle between diagnal and the sides are 45 degrees (maybe use sin or cos here...) Then you can calculate the volume of the one of the "missing volumes"

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pythag>

surreal meadow
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A tetrahedron fits perfectly inside a unit cube

placid zinc
#

Kek

surreal meadow
#

do you know what each of those words mean?

placid zinc
#

I guess the fit isn't really perfect

surreal meadow
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oh lol ig not

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A tetrahedron fits perfectly inside a unit cube
@alpine sable

alpine sable
#

hmm

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i still don't get it

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is it 1/3?

surreal meadow
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a unit cube has side lengths of 1

alpine sable
#

a unit cube is 1x1x1 right?

surreal meadow
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if you see "unit (shape)" chances are it's defining feature is of length 1

alpine sable
#

thx

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I solved it

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it's 1/3

fresh bolt
#

Find the inverse s of -1959 modulo 979 such that 0 ≤ s < 979. You must show all the detailed steps.

alpine sable
#

it's correct

zealous fractal
#

how to prove this cos^4 x + cos^2 x sin^2 x = cos^2 x

tidal sparrow
#

Take the common factor out

#

Left with answer😂

zealous fractal
#

oh jesus my brainnn

rough zinc
#

How would I write 4x^(10/3) with a root and whole exponent? I'd assume it to be curt(4x^10) but I'm really not sure--sorry.
I have a really icky foundation in math because I moved from Sweden to the United States when I was young. My american schools have had a lot more rigorous math programs than my Swedish school did.

tough hatch
#

where a is the greatest integer less than 10

old sable
#

Curt(4x^10) is correct I believe

ocean sealBOT
gray isle
#

assuming curt is supposed to mean cube root, it is not

tough hatch
#

where n and a are integers

rough zinc
# ocean seal

I don't quite understand what the bot is doing but yes, something like this

tough hatch
#

but you are familiar enough with the rules of exponents, yes?

#

@rough zinc

rough zinc
#

I mean

#

I obviously have some glaring holes with exponents

#

so I guess the answer would be not entirely

tough hatch
#

x^(a+b) = (x^a)(x^b)

#

10/3 is the sum of _ and _

#

both are something over 3

#

one of them is the greatest integer less than 10

#

the other is made obvious once you know the first addend

rough zinc
tough hatch
#

yes that's correct

#

10/3 = 9/3 + (?)/3

rough zinc
#

oh so 30

tough hatch
#

eh?

rough zinc
#

fuck me what am i doing

#

10/3=3+1/3

tough hatch
#

yes

#

you got it

#

you see what to do now?

rough zinc
#

but how does that help?

tough hatch
#

x^(a+b) = (x^a) (x^b)

tough hatch
rough zinc
#

or?

tough hatch
rough zinc
tough hatch
#

4x is your x

#

a is 3

#

and so on

#

a+b is the sum you mentioned earlier.

rough zinc
#

4x^3+cbrt(4x)?

tough hatch
#

no

#

why +?

#

and

rough zinc
#

oh sorry that's not meant to be there

#

but that doesn't make sense factor it in and it's 9 not 10

ocean sealBOT
rough zinc
#

ok yeah right

rough zinc
tough hatch
rough zinc
#

no 10

old sable
#

Because 10/3 is equal to 3 and 1/3

rough zinc
#

Oh sorry

#

i'm an idiot thank you so much for being so patient

ocean sealBOT
rough zinc
#

also sick bot

tough hatch
#

yeah, you forgot already about how you got 3 (from 9/3)

rough zinc
#

Yies

tight locust
#

wow!

#

great job!

untold warren
#

Got a quick q

#

trying to isolate for n on the n^3 summation formula so i can create a program, but just wondering how I could isolate for n to see if I can solve n for some summation of n^3

#

sorta like this

#

the line above is where i try to see if I can find a way to isolate for n to solve that n = 2 in that case

dire nacelle
#

Please help

gray isle
#

where are you stuck

fringe robin
#

int x^n is x^n+1/n+1 and for cot^2 x is 1+cosec^2 x and int for cosec^2 x is -cot x

hollow cypress
#

what's the Magma for the empty set?

placid zinc
#

I like to call it George

hollow cypress
sly mantle
hollow cypress
sly mantle
#

no

placid zinc
#

Oh wow I swear I didn't know your name haha

copper heath
#

Can someone help me? There's this question that was asked after the lecture where i can't rlly wrap my head around so insights are welcome

#

You are given an infinite countable set X and you define X^X is this still countable?

#

What do they mean by X^X how do you take the power of a set?

#

My feeling is that it's uncountable take X = N then you have N^N that seems uncountable but it's not rigorous in any way

vale wigeon
#

$X^Y$ is the set of all functions from $Y$ to $X$

ocean sealBOT
vale wigeon
#

and $X^X$, accordingly, is the set of all functions from $X$ to itself

ocean sealBOT
copper heath
#

aah u need to read it like that okay that makes sense

#

so it's basically a set made up of bijections

#

aldus countable since they're all bijections?

vale wigeon
#

no

#

not bijections

#

i said all functions

#

not all bijections

#

some functions from X to X are not bijections

alpine sable
#

I'm 13

#

Going into yth

#

7th

#

This makes no sense to me

rigid smelt
#

What doesn't make sense? Do you feel like going to 7th grade is too fast for you?

jagged imp
#

make a wish kid has the right skills for 7th grade at least

covert agate
#

hi

#

what’s the point of modular inverse if you can solve congruences using extended euclidean algorithm

placid zinc
#

What does it mean to "solve a congruence"?

#

Are you talking solving something like:
5x = 2 (mod 23)?

covert agate
#

yea

placid zinc
#

Bad example there's an obvious solution to that one haha

covert agate
#

just make it into a diophatine equation and solve for x

placid zinc
#

You make it sound easy lol

covert agate
#

no inverses needed

covert agate
#

for ax ≡ b (mod n)

#

i see modular inverse is usually introduced after linear congruences in number theory courses

#

whats the use of it if you cant solve eqns with ir

#

it

placid zinc
#

You can solve equations with it kek

#

I'm wondering what method you're currently thinking of

#

5x = 2 (mod 167)

#

I suppose you could just do euclid algo to get:
5m + 167n = 2

#

But then what if you get asked
5x = 27 (mod 167)?

#

If you did the exact same amount of work to get the modular inverse of 5, you could do both questions with no extra effort

#

But if you get 5m + 167n = 2 directly, you now have to repeat the process for 5m + 167n = 27

#

I guess that's pretty fringe haha, but in general the modular inverse is more info than other alternatives

mellow shard
#

hey i need some help with my maths project anyone ready for it?

alpine sable
#

i was going through linear algebra gone wrong:

#

does anyone know how to do example 1.5? there are no solutions for it 😦

sly mantle
#

find a 2 by 3 matrix $A$ so that $A+M=M+A=M$ for all $M\in M_{2\times 3}$

ocean sealBOT
#

Dreadful Encore of Twisted Karma

hybrid patio
#

Hello, in a lesson I was learning beginner trig and in this part of the equation i put 5sin30 and got -4... and my teacher said it was 2.5 not sure how?

#

oh wait nvm

#

was using google's calc and it messed it up

#

i used my normal calc and it works

placid zinc
#

@alpine sable
You can likely guess it. What matrix in M2×3 would best represent the idea of 0?

placid zinc
#

Exactly haha

alpine sable
#

... what a useless question 😠

placid zinc
#

Not at all!

#

Note what Dreadful has said above, we call this matrix a 0 because it doesn't change any other matricies with addition

#

This 0 has to exist, or else this isn't a vector space

alpine sable
#

I guess it is just trivial imo

#

also what does \mathbb F here mean?

#

field? what does that mean?

sly mantle
#

F is an arbitrary field

alpine sable
#

a vector space of bases?

placid zinc
#

What form 0 takes is usually trivial, yes.
0's implications are not trivial at all

vale wigeon
#

"a vector space of bases" what

alpine sable
#

what is a field?

placid zinc
#

You might have missed fields in your book, take a quick sec to look over it

vale wigeon
#

loosely speaking, a field is a set upon which you can do arithmetic

alpine sable
#

i know of galois fields with mod arithmetic

vale wigeon
#

i.e. add, subtract, multiply and divide (except by zero)

alpine sable
#

but what does that have to do with vectors

vale wigeon
#

...so you know the axioms that define a field, yes?

alpine sable
#

you can divide in fields?

vale wigeon
#

of course you can divide in fields

alpine sable
#

😮

vale wigeon
#

you can take reciprocals and you can multiply

#

R is a field lol

#

as is C

#

as is Q

alpine sable
placid zinc
#

A vector space is two structures squashed together.
The vectors form a group.
The scalars form a field.

vale wigeon
#

the axioms themselves are bureaucratic

#

kinda

alpine sable
#

but ik them now

#

i just searched it up

#

ty!

vale wigeon
#

mostly to ensure arithmetic works as you would expect it to

placid zinc
#

"squashed" means the vectors and scalars interact in specific ways

alpine sable
vale wigeon
#

a single vector is in a field as it is a collection of scalars
no

#

a vector shouldnt be thought of only as a list of scalars

alpine sable
#

do fields have an inherent ordering then?

placid zinc
#

It ends up being the case that all finite dimensional vector spaces can be represented this way haha

#

But no, that's not why something is a vector

covert agate
placid zinc
#

@covert agate
Yaya. It solves for all b at once

patent swan
#

0hai =]

How often do division-derived branches of the Fibonacci sequence outgrow the main sequence?

for example:

1 1 2 3 5 8 13 21 34
21 / 3 = 7 ; 7 * 5 = 35 ; 35 > 34

1 1 2 3 5 8 13 21 34 55 89 144 233
144 / 8 = 18 ; 18 * 13 = 234; 234 > *233

P.S.: I wish Markdown had colors for highlighting math sequence members for sequence property math... IRC had %C commands...

covert agate
placid zinc
#

Kek I guess there isn't much point of that

covert agate
#

if it’s a single problem

placid zinc
#

More info with the same amount of work

covert agate
#

proving things?

placid zinc
#

It does provide a bit of insight. That is, every number coprime to n has an "opposite". This helps wrap our heads around what's really going on, algebraically

#

This modular inverse pairs numbers together nicely

patent swan
#

so, does anyone know how often division derived branches of Fibonacci sequence outgrow the sequence itself? (see examples above, where I showed the first two such derivation points)

#

the first derivation point, 8, produces a very weak branch (8/2=4 ; 4*3=12 ; 12 < 13), 21 is the first derivation point where the branch outgrows the sequence

#

maybe this is the wrong place to ask this question...

placid zinc
#

Are you choosing your starting numbers at random?@patent swan

#

Like in that second example, 144 and 8

patent swan
#

no, I choose all Fibonacci numbers divisible by previous fibonacci numbers, 8 is the only way to derive a stronger branch out of 144

placid zinc
#

Ah I see. Then you multiply by the number after 8, and compare that to the number after 144

patent swan
#

divide 144 by 8, multiply result by 13 (next after 8), and compare to 233 (next number)

placid zinc
#

That's exactly the same as comparing
144/8 to 233/13

#

Except you only do this comparison when the first is an integer

patent swan
#

f_t+1-((f_t/f_d)*f_d+1)

#

dang, why doesn't Discord do super/sub?

placid zinc
#

Actually, that's exactly the same as comparing
144/233 to 8/13

patent swan
#

#imagineaplace, dang it hang it!

#

with non-integers like that, I'd think the outward branches would be more frequent than with an integer-only search

placid zinc
#

I mean you can choose to only include the search if 144/8 is an integer

#

But we can make the search more modular with this

patent swan
#

the first two integer outward branches (from 21 and 144) had their initial outgrowing by only 1, and were exactly 4 spaces apart within the sequence (members number 8 and 12)

placid zinc
#

I bet, actually, that this fraction is directly computable

#

Well, I guess it all is, haha

patent swan
#

1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, 4181, 6765
bold confirmed, underscore questioned, crossout means weak branch

#

10824 < 10946

#

this means 4 isn't quite accurate even for integers

#

this is important for the statistical mean risk of a double lash within the perimeter (not the twister core itself) of the cyclone, and other statistic mean intensity increases for things that exhibit the golden spiral pattern

#

it's also important for computing likelihood of double fronts of cyclones and anticyclones giving that extra strength to thunderstorms

#

living in a place with both sea and mountains nearby, the weather can be quite turbulent at times, and the forecast thing is a mess...

#

given the initial 1 1 gives a half circle and multiple spirals can emerge from a single completely circular core, I need to know the angular mean for outward branches of fibonacci spirals

#

what'd be the shortest formula for finding outward branches of the Fibonacci sequence/spiral?

clear vessel
#

Hey, if y = ax^k how do I write In y as subject?

placid zinc
#

Take the ln of both sides:
ln(y) = ln(ax^k)

#

Note the right can be expanded like so:
ln(y) = ln(a) + kln(x)

#

@clear vessel

harsh steeple
#

its known that AC = CD, how can i show that AC = CD = AD? it looks quite obvious

median tendon
#

well circles are symmetrical about the centre

alpine sable
#

This stuff blows my mind

alpine sable
harsh steeple
#

?

alpine sable
# harsh steeple ?

I'm going in 7the grade and this math stuff blows my mind I suck at math

weary jolt
harsh steeple
median tendon
#

if u can somehow proove CQ=QD

harsh steeple
#

oh yeah sorry about that

#

it is

#

AP also equals to PC

median tendon
#

then u can proove using pythagoreas theorem

harsh steeple
#

oh

#

haha i feel so dumb now

#

thank you!

median tendon
#

np

weary jolt
harsh steeple
#

enjoy math

alpine sable
#

Ill take a new approach

harsh steeple
# median tendon np

im kinda stupid lmao, can also prove it by proving that ACQ is congruent to AQD

alpine sable
ocean sealBOT
#

5'1 filipino subhuman incel

median tendon
#

what is your question

#

is it just solving the equation?

#

also both equations are satisfied, not just one of them

alpine sable
#

,tex He only tested $x = 6$ on
$$\sqrt{3x - 7} + \sqrt{2x - 1} = 0$$
and when it didn't work he said $x = 6$ satisfies $$\sqrt{3x - 7} - \sqrt{2x - 1} = 0$$ and didn't test $$-\sqrt{3x - 7} - \sqrt{2x - 1} = 0$$ or $$-\sqrt{3x - 7} + \sqrt{2x - 1} = 0$$

ocean sealBOT
#

5'1 filipino subhuman incel

median tendon
#

maybe because when he did the first equation, he saw it was 11+11 and so putting a negative sign infront of one term would satisfy the problem?

alpine sable
#

Your third equation always works if the first works. And the fourth always works if the second works

median tendon
#

^ just multiply -1 by both sides to see that

alpine sable
#

I got it now, thanks

median tendon
#

np

rigid smelt
#

,rotate

ocean sealBOT
rigid smelt
#

use logarithms

#

uhhh use logarithms? especially take advantage of the property that log_a(a^x)=x

vivid comet
#

i forgot what logarithms are or i just don't recognize the name in English. what do i do exactly?

rigid smelt
#

ok firstly tho, is that 1.02 or 7.02?

#

ok

#

so try to isolate (1.02)^n and then take the log base 1.02 on both sides

#

this is a giveaway at this point

alpine sable
#

First write your function as an equation: $k=2500 \cdot 1.02^n$

ocean sealBOT
#

farbbohrer

vivid comet
#

then do i take 2500 over to the other side of the =?

alpine sable
#

yes

#

Do you multiply or add 2500 on the right side?

vivid comet
#

multiply so k/2500=1.02^n

alpine sable
#

yes

vivid comet
#

now what is this logarithm i have to do to get n

alpine sable
covert agate
#

it should be true for pairwise coprime n1 … nk

covert agate
vivid comet
#

i watch it and understand logs but idk how to enter it

alpine sable
#

You should have a log button on your calculator. Depending how your calculator works you either can do calculate the log with the correct base or you need to use a trick to calculate it with the correct base.

#

But you dont need to that for your current task.

#

You "just" have to rewrite it with logarithms.

vivid comet
#

now what?

alpine sable
#

Question: What is $log_1.02(1.02^n)$ ?

ocean sealBOT
#

farbbohrer

alpine sable
#

Sorry let me reformat that

#

Question: What is $log_{1.02}(1.02^n)$ ?

ocean sealBOT
#

farbbohrer

alpine sable
#

Forget your calculator

#

It can only calculator the logarithm for the base of 10. But our base is 1.02

vivid comet
#

then what do i use?

alpine sable
#

Your brain

vivid comet
#

breh

#

rn i got 2=1.02^n

carmine lion
#

lmfao

#

use ur log rules

#

u don't need a calc for this

#

let me ask a similar related question

#

Question: What is $log_2(2)$ ?

ocean sealBOT
vivid comet
#

what?

alpine sable
#

$log_2(16)$ is the question as to what power should I raise 2 to get 16.

ocean sealBOT
#

farbbohrer

carmine lion
#

this channel is occupied

alpine sable
#

So what would $log_{1.02}(1.02^n)$ mean

ocean sealBOT
#

farbbohrer

tidal solar
vivid comet
#

to what power do i have to raise 1.02 to get 5000/2500 or 2

carmine lion
carmine lion
#

do you see that $log_2(2^2)=2log_2(2)$

ocean sealBOT
alpine sable
vivid comet
#

i just want a way to enter log1.02(2) into my calc cause i think i got that far at least.

alpine sable
#

I will you give a hint how to calculate the logarithm with your calculator (if there are no variables in it).

#

$log_{1.02}(2)=log(2)/log(1.02)$

ocean sealBOT
#

farbbohrer

vivid comet
#

so they're the same?

alpine sable
#

right side is what you should put in in your calculator

vivid comet
#

got it but i don't quite understand the inputs yet.

#

so i have my answer but i don't get how i got there

#

in the vid u send he entered his formula differently.

alpine sable
#

$5000=2500\cdot 1.02^n$

ocean sealBOT
#

farbbohrer

alpine sable
#

$5000/2500=1.02^n$

ocean sealBOT
#

farbbohrer

alpine sable
#

then we use logarithm

#

$log_{1.02} (2) = log_{1.02} (1.02^n)$

ocean sealBOT
#

farbbohrer

alpine sable
#

right side equals n

#

so we get $log_{1.02}(2)=n$

ocean sealBOT
#

farbbohrer

alpine sable
#

Which you have to calculate with your calculator using the trick i posted

#

$\frac{log(2)}{log(1.02)}=n$

ocean sealBOT
#

farbbohrer

alpine sable
#

So we get $n\approx 35$

ocean sealBOT
#

farbbohrer

scenic pulsar
#

Hey there just wondering why we are using sin for i-direction and os for j-direction, can't seem to wrap my head around this

alpine sable
#

What is the definition of sin and cos?

scenic pulsar
#

wdym?

#

Like what they mean?

alpine sable
#

Yes. You use them in triangles and there they have a definition.

scenic pulsar
#

I mean sin=opposite/hypotenuse

#

cos=adjacent/hypotenuse

ocean sealBOT
alpine sable
median tendon
#

Don't need to, use chain rule

alpine sable
#

whats that

median tendon
#

You dont know chain rule, quotient rule and product rule?

alpine sable
#

i probably do but i dont know how its called in english

#

ill google it rq

#

oh yeah i know what it is

#

ok ill use it thanks

median tendon
#

np

alpine sable
#

i know i dont need to open the parentheses but will it make it easier to solve?

median tendon
#

For that, might be like 10 sec faster. But for more complex equations, chain rule saves alot of time

alpine sable
#

oh ok

rough tusk
vivid comet
alpine sable
#

@vivid comet 5000/2500=2. And we use the logarithm on both sides of the equation

vivid comet
mystic sinew
#

why can't you come up with a combination of the real and imaginary bits of a complex number such that it's equal to another complex number?

vale wigeon
#

what do you mean?

mystic sinew
#

like why can't we figure out some x +yi = zi
(x != 0)

#

I understand this is probably wrong? but I wanna know why it's wrong

vale wigeon
#

so you are essentially asking why two complex numbers that have matching real and imaginary parts are in fact equal?

mystic sinew
#

no

#

that's not what I am asking at all

mystic sinew
median tendon
vale wigeon
#

complex numbers are but points in the complex plane

#

you are asking whether or not it is possible to have (x,y) describe the same point as (0,z) without x being 0

#

assuming you intended for x, y and z to be real, of course

median tendon
#

If that helps visualise it for u

mystic sinew
#

it's a correct answer though I guess

alpine sable
#

How does subtraction work?

mystic sinew
#

fair point mr far

vale wigeon
mystic sinew
#

I think he's trying to make an argument

alpine sable
#

Things in math are equal if you subtract them from each other and the solution is 0

mystic sinew
#

gonna go for some meditation be back in 5

alpine sable
#

@mystic sinew In complex numbers it would be better to argue how can something be equal if there is a distance between those points. And we can easily show that the distance between such points is always greater than x.

alpine sable
#

What's the answer to this and where can I practice with these types of questions?

remote heron
#

3 to 4, i think

ocean sealBOT
calm solar
#

There are 20 more men than women in a movie theater. If 10 more married couples had entered the room, the number of men would have been twice the number of women.

Express the two unknowns in the sentences given above with a system of equations.

Men = M
Women = F

M = F + 20
M + 10 = 2. (F + 10) =>>> Why is not 2.(M + 10) = F+10

ocean sealBOT
hearty cliff
remote heron
hearty cliff
#

the new number of men M+10 is twice the new number of women F+10

#

so M+10 = 2(F+10)

alpine sable
#

Thanks guys

vale wigeon
hearty cliff
#

yeah haha

tranquil tulip
#

how do u find the area of this?

vale wigeon
#

who pinged me

median tendon
#

Break it up unto smaller shapes

tranquil tulip
#

what shapes should i break it up to

native temple
# vale wigeon who pinged me

Uhhh me saying let me google that for you is impossibly based….then deleted messages as this isn’t the place for discussion

median tendon
#

Into shapes that you know how to calculate the area of

tranquil tulip
#

ok thx

median tendon
#

I can see half a circle for example

tranquil tulip
#

We haven’t learned how to find the area of anything yet

#

i’m just gonna count

median tendon
#

You dont know how to calculate the area of a circle or triangle or square?

tranquil tulip
#

no i know how to do a square but i forgot circle and triangle

#

I did it like in 7th grade 3 years ago

median tendon
#

Circle area = $\pi r^2$

#

Triangle is just half of the area of a square

ocean sealBOT
#

_Youssef_

tranquil tulip
#

do you know how to do 2/1 = -1/3x

median tendon
#

Ok first thing, what is 2/1?

tranquil tulip
#

2

median tendon
#

What do you need to multiply -1/3x to make it be just x?

tranquil tulip
#

ohhh

#

thanks i forgot algebra for a second

copper wedge
#

need help simplifying 32/27 / -1/6

#

the answer says its -64/9 but i dont know how to get there

wary stream
#

Do you know the rule when dividing with fractions?

copper wedge
#

its something like multiply the reciprocal right

wary stream
#

Yes

copper wedge
#

but i dont know how u would get a 9 on the bottom

#

nor would that equal -64 on the top

sage bronze
#

u have to simplify

wary stream
#

You have $$\frac{32}{27} * \frac{6}{-1}$$

ocean sealBOT
#

dldh06

alpine sable
#

hi guys

wary stream
#

You can multiply across, like normal, then simplify or simplify parts of it now

copper wedge
#

technically yes and no

#

i have 32 Over 27 which is also OVER -1/6

alpine sable
#

how to manage our time?

wary stream
alpine sable
#

oh

wary stream
sage bronze
copper wedge
#

so now my answer wouwld be 192 / - 27 / 6

ocean sealBOT
#

HELLOBELLO

wary stream
#

I already told you, this channel is busy

wary stream
alpine sable
#

oh wait

#

wrong channel

copper wedge
#

no nvm it would be 192/-27

sage bronze
wary stream
#

Now, simplify

copper wedge
#

omg

#

idk how i missed that

wary stream
#

$$\frac{32}{27} * \frac{6}{-1} \equiv \frac{32}{39} * \frac{23}{-1} \equiv \frac{32}{9} * \frac{2}{-1}$$

ocean sealBOT
#

dldh06

sage bronze
#

which is -64/9

#

🙂

wary stream
golden arch
#

How do i check if this is a linear differential equation?

uncut tapir
#

Use a linearity test.
For linear functions
f(x + c) = f(x) + f(c)
f(ax) = af(x)

You want to rewrite the equation as
f(y'', y', y) = 0 and apply the tests

golden arch
#

Thanks

torpid narwhal
#

if i have a set like Q(sqrt(2)) where the elements are of the form a + b*sqrt(2)

#

(a, b are members of rationals)

#

if it were a field (which it is) how would i go about finding its multiplicate inverse?

#

i tried expanding 1 / a + b*sqrt(2)

#

by amplying with a - b*sqrt(2)

#

etc

#

but it's different from a solution i found online

fervent gust
torpid narwhal
#

a - b*sqrt(2) / (a^2 - b^2)

#

am i bad at 6th grade algebra?

fervent gust
#

ye

alpine sable
#

if -4x + 3x = -x , what does -x equal to as a number

#

-1 ?

fervent gust
torpid narwhal
#

omg yeah

#

thanks

torpid narwhal
#

it can be anything

alpine sable
#

new here

#

xd!

torpid narwhal
#

you can evaluate that expression with anything

#

in the domain of the expression

#

@fervent gust now im being asked if "the set of all polynomials with integer coefficients forms a field"

#

but i've never thought of sets of polynomials before so im confused

fervent gust
#

err whats your problem?

#

you dont know what a set of polynomials is?

untold marten
#

hmmm helo

torpid narwhal
#

basically

untold marten
#

help

#

so i never take algebra before but i have an algebra test is coming, and its extremely imprtant to me

fervent gust
#

rip

oak chasm
#

@untold marten Algebra 1?

#

If you get stuck on something, you can ask here.

untold marten
#

yay

#

thats wut im doing lol

torpid narwhal
#

@fervent gust so is it the set of elements of the form n, nx, nx^2, nx^3, nx^4, ..., (with n any integer)

alpine sable
#

khan academy also offers easy practice to build up confidence

#

that also helps me understand things i don't understand

fervent gust
torpid narwhal
#

oh sure

#

good

ocean sealBOT
#

uyitroa

torpid narwhal
#

so 1/x is not a polynomial?

fervent gust
#

nope

torpid narwhal
#

so x doesnt have an inverse

#

so not a field

#

cool

fervent gust
#

yea

harsh steeple
#

theres the trigonometric identity: cos a = sin (90 - a), can i also say that cos 2a = sin (90 - 2a) ?

#

im just confused

night geyser
#

Yes.

harsh steeple
#

alright, thank u

night geyser
#

You can replace a with whatever

#

As long as you do it on both sides, the identity holds

#

cos(goldfish) = sin(90 - goldfish)

fervent gust
#

damn now I can't unsee

whole charm
alpine sable
#

Can you write it out as an equation?

torpid narwhal
#

how can i find the multiplicative inverse of a field's elements

#

that defines addition like (a, b) + (c, d) = (a + c, b + d)