#help-0

1 messages · Page 740 of 1

vale wigeon
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you've fallen victim to the freshman's dream

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$(a+b)^2 \neq a^2 + b^2$

ocean sealBOT
tired hamlet
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yeah I get that I thought that the squaring just undoes the square root?

vale wigeon
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$(\sqrt{x-3} + \sqrt{2x+1})^2$ is still not the same as $(\sqrt{x-3})^2 + (\sqrt{2x+1})^2$

ocean sealBOT
vale wigeon
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squaring doesn't distribute over addition like that

tired hamlet
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oh so it's (x-3+(2x+1))(x-3+(2x+1))

vale wigeon
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what

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no?

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okay look

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can you tell me how (a+b)^2 expands?

tired hamlet
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(a+b)(a+b)

vale wigeon
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i said expand.

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while it is true that squaring a number means multiplying it by itself, that's not what i asked for here.

tired hamlet
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a^2+2ab+b^2

vale wigeon
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great

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so now, can you apply this to (sqrt(x-3) + sqrt(2x+1))^2?

tired hamlet
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yeah I got it it would be $3x+2\sqrt{2x^2-5x-3}-2$

ocean sealBOT
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jb8!!!

vale wigeon
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strange ordering of terms but whatever

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yes that is correct

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does this answer your question of "why would i get roots"?

merry herald
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oh if thats it then thanks

tired hamlet
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yeah thanks i got it. and just set that equation equal to 2x+8

alpine sable
#

anyone inte conditional possion distributions ?

halcyon pulsar
#

I've solved this question for more than 30minutes now
First I found the Area of the sector
And now finding the Area of the traingle inside the sector
I would next Subtract area of sector and traingle
But all of this is taking alot more time and wierd calculations than it should
Help me in solving dis •~•~•

merry herald
#

so we could just do 180-a-b-c-d=360 ?

remote iron
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Solve radius

halcyon pulsar
remote iron
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its a 1

halcyon pulsar
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For what?

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As a length?

remote heron
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,rotate -90

ocean sealBOT
remote iron
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they are unit squares

halcyon pulsar
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Okie

wispy olive
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I do not know the answer.

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But according the rules you should ping once.

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But your irritation is understandable.

remote iron
# ocean seal

<@&286206848099549185> anyone able to help with my q?

wispy olive
#

Woah 1k+ Subscribers nice.

remote iron
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Thank you! love

placid zinc
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If the center of the four squares is (0,0), then (-1, 1) is on the circle, and (2, 1/2) is on the circle

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(x - m)² + y² = r²

wispy olive
remote iron
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oh that's true. (Kaynex)

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wait, 2, 1/2?

placid zinc
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,w system of equations (-1 - m)^2 + 1 = r^2, (2 - m)^2 + (1/2)^2 = r^2

placid zinc
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Looking like the radius is √185 / 8

remote iron
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wait explain how u got those points?

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cause i think somethings fishy

placid zinc
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Let the center of the four squares be (0,0)

remote iron
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center as in the center of the circle yes?

placid zinc
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I know that the center of the four squares is not the center of the circle

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(in fact it's 3/8 off)

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Then (-1, 1) is a point on the circle

remote iron
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are u saying the top left corner of the square is -1 1?

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because i don't think u can do that since its not centred.

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like in the circle.

placid zinc
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I can do whatever I want and you can't stop me

remote iron
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I am not stopping you lol.

placid zinc
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Jokes aside, note that I am putting the squares on a Cartesian Plane, and ignoring the circle for now

remote iron
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I am saying that how is it -1, 1 if its not on the circle?

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Alright, but what are you making the centre then

placid zinc
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I am defining that (0,0) is the center of the four squares

remote iron
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Alright...

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so then top left corner is -1, 1

placid zinc
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Right! And that's a point on my circle

remote iron
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sure...

placid zinc
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And similarly, (2, 1/2) is also a point on my circle

remote iron
#

and bottom left is 2, -1/2?

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-1/2 no?

placid zinc
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You could also pick that one

remote iron
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oh yes.

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then...?

placid zinc
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So I summon the equation of a circle that is symmetric over the x-axis:
(x - m)² + y² = r²

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Note it has two unknowns, m and r. So I'll need two points to find them

remote iron
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...

placid zinc
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You seem underwhelmed

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Oh, I just let Wolfram do the actual algebra from this point forward

placid zinc
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That is, I gave it the equation, with the two points subbed in

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👻

alpine sable
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2 tan theta into 2 cot theta =

empty kindle
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how to find k?

quaint trout
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thonkzoom what is k?

vale wigeon
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i have a hunch that they intended for you to name the one value that the common ratio of a GP cannot be.

empty kindle
#

.?

vale wigeon
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the common ratio of your GP is r here

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what can it NOT be?

empty kindle
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same with k?

vale wigeon
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....

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forget about k.

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sigh ok i guess my attempts at making you recall this have not worked like i thought they would

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it's 1.

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the one forbidden value of the common ratio of a GP is 1.

lime lintel
icy trail
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i think the average rate of change will just be the gradient of the line between t=3 and t=5

lime lintel
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so i substitute it into the equation, then what?

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theres no graph

icy trail
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its just the gradient of the line between those two points

lime lintel
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...?

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10..?

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ok wait

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so when t = 3, n = 7.5 and when t = 5, n = 17.5

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minus 7.5 from 17.5?

icy trail
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gradient = change in output / change in input

lime lintel
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so 10.?

icy trail
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have you divided by the change in input

lime lintel
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whats change in input?

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how do u know which ones which?

icy trail
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change in t

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you could just replace n with a y and t with an x to do change in y / change in x but

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the gradient for this question is change in n / change in t

lime lintel
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OHHHHH

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OH OKKK

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THAT MAKES SENSE

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right

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thanks dude

icy trail
slate fossil
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I need someone to check my answer

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Number 5

vale wigeon
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your answer (C) is correct

slate fossil
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Ah thx

wintry vortex
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So why is it different converting it back from decimal to degrees?

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I put tan (0.238) in and it didnt give me a degree

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Im doing their equation and its giving me itself as an answer 😖

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WHERE DID THE DEGREE COME FROM?!?! this program explains nothing and its infuriating o_O

alpine sable
#

wdym the degree? do you mean where did 10.6° come from?

wintry vortex
#

yes

topaz wedge
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What’s 1 unvigintillion minus 2 novemdecillion 1 nonillion and 1 quadrillion? I can’t use Siri cause it’s too big and doing it on paper is not possible.

alpine sable
# wintry vortex yes

it is written, if you type in your calculator arctan(0.191) it will output 10.8°

wintry vortex
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okay that got it, what did the arc part of it mea?

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mean?

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Why did that work?

alpine sable
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are you new to inverse trig functions?

wintry vortex
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yes

alpine sable
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okay

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have you learned inverse functions in general?

wintry vortex
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If I have it was a long time ago. Its been around 10 years since I did a math class.

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Im relearning alot.

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but this is the last of the classes I need for my associates 😮‍💨 Im a freakin aircraft mechanic lol, idk why they think i need calc

alpine sable
#

okay so you may remember that the inverse function of, say, $f$ is denoted as $f^{-1}$

ocean sealBOT
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Al𝟛dium

alpine sable
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one clear example might be e^x and ln(x)

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,w plot e^x & ln(x) from 0 to 10

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okay wait

wintry vortex
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I may be more screwed than I thought, that doesnt look like english to me 0_0

alpine sable
wintry vortex
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Okay, so im following that a inverse function negates the original function. thus F^-1 being the inverse of F but the e^x lost me completly

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I still dont fully understand how its used practically though

carmine lion
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think of any 1 to 1 function

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i.e a function that passes both the horizontal and vertical line test

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then draw the line y=x

alpine sable
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i'm looking for a graph for you to see it's reflection with the line y=x

carmine lion
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and try to reflect that function in this line

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basically, an inverse is a reflection of a one to one function in the line y=x

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y=x is a mirror

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for functions and their inverse

wintry vortex
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would that make the lines parellel?

carmine lion
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hmm not quite

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,w graph x^2 and sqrt(x) and x from 0 to 2

carmine lion
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its kinda hard to tell

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wolfram bot bad at graphh

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there we go

wintry vortex
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so thats an inverse function?

vale wigeon
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@topaz wedge it's not that hard to do it on paper. "1 unvigintillion" is only 67 digits long.
the answer to your question, if you want to know it so bad, is 999,997,999,999,999,999,999,999,999,999,999,998,999,999,999,999,999,000,000,000,000,000, which i am not going to spell out in full unless you want to hear a torrent of "nine hundred and ninety-nine footillion"

wintry vortex
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Ya'll are saints for helping me figure this out btw ❤️

manic glade
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is this the correct way to describe the set of all infinite sized subsets of B?

vale wigeon
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no, this gets you only the countable ones

manic glade
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thats the ones i need yes B is all even natural numbers

carmine lion
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oi corylus

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this channel is occupied

manic glade
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i was just wonderin on which side the x subset B is supposed to be

carmine lion
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please move to another one

alpine sable
# wintry vortex so thats an inverse function?

yeah and well talking about inverse trig functions we have sin with the domain and image of [-π/2, π/2] and [-1,1] then it's inverse will be arcsin, with domain and image [-1,1] and [-π/2, π/2] respectively

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similar goes with arctan and arccos.

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,w plot sin(x) & arcsin(x) from -π/2 to π/2

ocean sealBOT
wintry vortex
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So function if memory serves just means the line doesnt cross x or y a second time. So would an inverse function mean that it all intsects at some point? then does cross x and y a second time?

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evil people invented math 0_0

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ok so arcsin or arccos would just be the opposite of sin or cos then?

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This whole question series has my brain in a knot

surreal meadow
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in simple terms, a function of x means that for every single x, there is only 1 y

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that is, every x value in the domain of the function only has 1 value corresponding to it

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that's why we do the "vertical line test", as it tells us wether an x value has more than 1 y value associated to it

wintry vortex
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But doesnt it have a Y above and below X? or are we only talking intersecting with 0 x?

surreal meadow
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i'm confused by the question

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have you seen the graph for sin(x)?

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you can see it crosses the x-axis multiple times, yet it is still a function

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this is because at every x-value, there is a single y value

wintry vortex
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Ok, I think i understand

surreal meadow
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an inverse function $f^{-1}(x)$ is how we go from $f(y)=x$ to $y=f^{-1}(x)$

ocean sealBOT
#

maximo

surreal meadow
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so for example

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if we have f(x) = x

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the inverse function $f^{-1}(x)$

ocean sealBOT
#

maximo

surreal meadow
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can be found by setting y=f(x), y=x

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well that's a pretty awful example

lucid beacon
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So like, we do something to x and get a new number. The inverse function is going from the new number back to x

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I don't know if that's technically correct but

surreal meadow
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f(x)=x^2 is a better example

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f(x)=x^2

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y=f(x)

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y=x^2

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flip x and y

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x=y^2

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sqrt(x)=y

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we have that the inverse of f(x)=x^2 is f^-1(x)=sqrt(x)

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do you see what i did?

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you're solving for y in the equation f(y)=x

wintry vortex
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tbh, not really. I think my brains to fried to do much more tonight =/

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Man, this was not the math for them to just plop me back into

surreal meadow
#

what exactly is confusing about it

wintry vortex
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sadly all of it. But i think I at least get the basic concept of function and inverse function and how to find them on a calculator like my homework was asking

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Sadly its already throwing new curveballs at me and idk if u have the energy to learn em

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I was hoping to get a few more questions done just to whittle down at it over the week but I didnt make it very far haha

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Thank you a ton for all the help ❤️

hexed lintel
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hi

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the first one is identity and change the voice

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i dont understand that

surreal meadow
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@hexed lintel i'll dm you a link to the english server

hexed lintel
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k

surreal meadow
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they'll be of more help than a math server i'm sure

kind parcel
#

Can someone help

ocean sealBOT
surreal meadow
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do you know how to find the slope of that tangent?

tough hatch
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to determine the coordinates of A, just solve for the greater x in 4x-x^2 = 0

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@kind parcel

alpine sable
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you can find the differential for the curve

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then input x as 1

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then create the eqn of the tengent from that

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tangent*

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then equate that x to 0

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then you can find the B coordinate

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X is directly proportional to y, or varies directly with y, if x/y = k

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For some constant k

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You can find the constant and solve for y

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can we chat privately? If it’s alright?

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Nah

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ok:)

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So do you get how to do it? I can show you how the first is done

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no I don’t get it. please give me an example

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x varies directly with y, and we have that when x=24 y=8

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Then x/y = 3, which is our constant k

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Then, when x = 6, 6/y = 3, so y = 2

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that’s it?

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Yea

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Unless I misunderstand what varies directly means, but I think im right

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so the final answer is 2?

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Yes

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alr alrr thanksss

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Np

winter mango
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suppose we have a binary string of length 15, how many possible strings have exactly 6 zeroes?

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are we supposed to use permutations or combinations in this question?

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i feel like it should be permutations because the order in the string matters, but the answer seems to be combinations

alpine sable
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permutations are a subset of combinatorics

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But the order doesn’t really matter that much here

winter mango
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sorry, how is that?

alpine sable
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Like, you have no real restrictions on the order of the zeroes, since you’re computing all possible arrangements

winter mango
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i think i understand, it's still sorta hazy though

alpine sable
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Sorry, I shouldnt have engaged with this question since I don’t have the answer yet

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But i’ll come back once I figure it out fully

winter mango
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it's all right, i think you have the right concept i am just getting more used to this stuff

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thanks for answering

alpine sable
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Np

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Ok I think it’s (15 \choose 6)

ocean sealBOT
winter mango
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yeah that's the correct answer, or 15c9 but they're identical

alpine sable
#

Depends on how you conceptualize it

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is this linear

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In use

winter mango
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i think i get it now

alpine sable
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Ok, im glad

winter mango
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it's easier to visualize as a sort of successes and failures

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that's why the order doesn't matter

alpine sable
#

Cpl could you help me in question 1, if finished.

unborn dome
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can someone help me with this question im really confused lol

alpine sable
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how do i express cosxsiny as a difference of sine functions

alpine sable
unborn dome
#

can anyone explain if this video used the sum and difference identity to solve this problem?

alpine sable
glass lichen
unborn dome
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so its not sum or difference formula @glass lichen ?

glass lichen
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it is...

tough hatch
glass lichen
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if you read the ss you posted.. you'd see they used one

unborn dome
#

ah t

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thank you

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im doing a review sheet rn so im a bit confused on topics lol

ocean sealBOT
covert wagon
#

anyone here understand n and o

native cloud
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Why is there a comma inside the root?

wind bane
#

what is the question?

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commas are sometimes used in place of decimal points in other places if i recall correctly

covert wagon
native cloud
#

Did the question ask to simplify?

covert wagon
#

thanks

native cloud
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Without a calculator?

covert wagon
native cloud
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I would be very hard without a calculator;;;

covert wagon
native cloud
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Not sure how it can be more simplified

covert wagon
#

the answer is square 3/10 - square 2/5

surreal meadow
#

~.3

covert wagon
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i search in photomath

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thanks for helping

native cloud
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Ohhh in fractions

covert wagon
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oh that was fractions

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im not good at english

native cloud
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That's okay

teal garnet
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can someone explain how these are equal?

surreal meadow
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l'hopital

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the theorem is essentially

fallow ruin
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Only when you encounter 0/0 or ∞/∞ !

tight locust
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lim x->inf (1/x) = lim x->inf (0/1) = 0

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that was a 1/inf limit and it still worked

tight locust
sage bronze
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it doesnt always work

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there will be exceptions

surreal meadow
devout sigil
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Doesn’t it still works for 0 multiplied by +-infinity?

surreal meadow
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which is simply 0 over 0

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or infinity over infinity

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as long as you can rearrange it as such

fallow ruin
tight locust
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lim x->0 (sinx*x) = lim x->0 (sinx/(1/x)) = lim x-> 0 (cosx/(-1/x^2)) = lim x->0 (-x^2*cos(x)) = 0

surreal meadow
ocean sealBOT
#

maximo

tight locust
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of course not. you have to express it as a quotient. then you can use l'h
x/1 = x'/1' = 1/0 = infinity

fallow ruin
#

no, you didnt check the limits

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first you must encounter 0/0 or inf/inf, then you can apply l'hopital

surreal meadow
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$\lim_{x\to 3}\frac{2x+1}{3x+1}\neq\lim_{x\to 3}\frac{2}{3}$

ocean sealBOT
#

maximo

fallow ruin
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excellent example

sage bronze
#

yes

surreal meadow
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lets make this easier

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if you can prove that lhop works for every f(x)/g(x), regardless of indeterminate form

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then i'll cede that you're right

tight locust
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that was never my claim. just that it didn't necessarily have to be a 0/0 or inf/inf limit

surreal meadow
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and we never claimed that it had to be 0/0 or inf/inf?

sage bronze
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on every f(x)/g(x)

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without indeterminate form

surreal meadow
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i'd like to see the proof you wrote up again though

alpine sable
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lol

surreal meadow
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because if you can tell me that $\lim_{x\to 3}\frac{2x+1}{3x+1}=\frac{2}{3}$

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then there's either something fundamentally wrong with math or your proof

sage bronze
ocean sealBOT
#

maximo

alpine sable
surreal meadow
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nono no one actually tried to

sage bronze
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lh doesnt

surreal meadow
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just using it as an example of why lhop doesn't always work

sage bronze
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work for all

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yeah

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sorry my communication skills are a bit rusty

alpine sable
#

If two sides are given in a Right angle Triangle, how to find all angles inside it?

surreal meadow
#

have you heard of the pythagorean theorem

sage bronze
alpine sable
#

When is L'Hopital's rule not applicable? When your limit is a finite number divided by zero or infinity divided by a finite number. The limit has to be indeterminate such as 0/0 or infinity/infinity.

alpine sable
alpine sable
surreal meadow
#

law of cosines

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or just trigonometry

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that's probably easier

sage bronze
#

yeah

surreal meadow
#

SOHCAHTOA to be more specific

sage bronze
surreal meadow
#

sin = opp/hyp, cos = adj/hyp, tan = opp/adj

ocean sealBOT
#

Chai T. Rex

sage bronze
#

so its a acronym

alpine sable
sage bronze
#

ok

sage bronze
alpine sable
#

i use
PBP
HHB
SCT

sage bronze
devout sigil
#

Ever heard of sine rule

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?

alpine sable
alpine sable
surreal meadow
alpine sable
#

but that question was clearly not directed toward me

devout sigil
#

Yes but u can use it to find the ratio of lengths

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Of the sides

alpine sable
#

tbh no offense itd be easier to use pythagoras since its a right angled triangle

devout sigil
#

Yes this is just for checking

alpine sable
#

and im sure a person who's asking this rudimentary question doesnt know what sine rule is/respectfully

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anyways i gtg

devout sigil
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A/sin a=B/sin b where a and b are angles in a triangle and A and B are corresponding opposite sides to their respective angles

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How is it not applicable?

surreal meadow
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you only know 2 sides

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and a 90 degree angle

devout sigil
#

The two angles are complimentary

surreal meadow
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oh i forgot about that 90 degree angle

devout sigil
#

Facing the non-hypotenuse

surreal meadow
#

yeah should be easy with law of sines as well

devout sigil
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If my two unknown angles are a and b I can say b=90deg-a

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Side A/sin(a)=side B/sin(90-a), u can expand with formula side B/cos a

surreal meadow
#

that's unecessary

devout sigil
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Which is why I agree if u prefer pythagoras, but u can still use this

surreal meadow
#

hyp = leg/sin(a)

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you already know all 3 side lengths

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you can find 1 angle like that and just solve like you said for a+b=90

devout sigil
#

Because I know people who don’t even know Toa cah soh

sage bronze
#

i didnt know

devout sigil
#

@alpine sable maybe someone didn’t even know the correlation between complimentary angles

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@sage bronze do u know sine rule or cosine rule?

sage bronze
devout sigil
#

In that case u can still use my approach to tackle such a problem

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“Doesn’t know what sine rule is”

fickle cliff
#

how x^2+x+1/4 = (x+1/2)^2 ?

sage bronze
ocean sealBOT
#

HELLOBELLO

fickle cliff
#

yes

sage bronze
ocean sealBOT
#

HELLOBELLO

fickle cliff
#

a=x^2 , b= idk

alpine sable
#

How do we find trigonometry ratios for specific angles

sage bronze
sage bronze
fickle cliff
#

b=1/4 ?

sage bronze
#

instead of a=x^2 and b= 1/4

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it should be a= x and b = 1/2

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can u see why

#

?

alpine sable
#

simplification?

fickle cliff
sage bronze
#

if a= x^2 and b = 1/4

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$(a+b) = (x^2 + 1/4)^2$ if a= x^2 and b = 1/4

ocean sealBOT
#

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

fickle cliff
#

where did ^2 came from?

sage bronze
#

try to find values of a and b such that $a^2 = x^2$

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and $b^2 = 1/4$

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@fickle cliff

ocean sealBOT
#

HELLOBELLO

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HELLOBELLO

fickle cliff
#

i kinda understood

sage bronze
#

ok

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so what did u get as values of a and b

fickle cliff
#

(x+1/2)^2 because x^2 + 1/4^2 can also be inside brackets and ^2 can be outside

#

$x^2 + 1/4^2=(x+1/4)^2$

ocean sealBOT
#

motoboi

sage bronze
#

see

#

$x^2 + x + \frac {1}{4} = (x)^2 + 2 \times x \times \frac {1}{2} + (\frac {1}{2})^2$

ocean sealBOT
#

HELLOBELLO

sage bronze
#

from here

sage bronze
#

to get $x^2 + x + \frac {1}{4} = (x)^2 + (2 \times x \times \frac {1}{2}) + (\frac {1}{2})^2 = (x+ \frac {1}{2})^2$

fickle cliff
#

wait let me do it on paper

sage bronze
#

yeah

ocean sealBOT
#

HELLOBELLO

alpine sable
#

This channel occupied?

fickle cliff
#

yes

#

ok so
in $x^2+x+1/4$ u converted $1/4$ into $(1/2)^2$ because $(1/2)(1/2) = 1/4$
the $x^2$ can be also written as $(x)^2$
$(2
x1/2)=(x1)=x$
$(x)^2+(1/2)^2=(x+1/2)^2$

Now my question is that where the x in $(2x1/2)$ is gone?

sage bronze
#

me confused now

#

wdym by this

fickle cliff
#

Im still not used to this bot ;-;

sage bronze
#

u can

#

just write

#

it

#

and send a picture

fickle cliff
#

yup wait a min

tough hatch
#

for example $2=3$, which is not true

ocean sealBOT
#

motoboi

tough hatch
#

this is just boring text, $this is text in math mode which looks ugly$, this is normal text

ocean sealBOT
fickle cliff
glass lichen
#

dont use $\times$ and $x$ in the same thing

ocean sealBOT
glass lichen
#

but we know $(a+b)^2=a^2+2ab+b^2$, here $a=x$ and $b=\frac{1}{2}$

ocean sealBOT
glass lichen
#

so clearly the 2ab term is just x

fickle cliff
#

but its not $2x$ its just $x$

ocean sealBOT
#

motoboi

glass lichen
#

yeah....

#

Im aware

#

what's your point?

fickle cliff
#

it needs to be $2x$ right?

sage bronze
ocean sealBOT
#

motoboi

glass lichen
#

$2\cdot\frac{1}{2}\cdot x=x$

ocean sealBOT
fickle cliff
dawn galleon
#

<@&286206848099549185>

fickle cliff
# dawn galleon <@&286206848099549185>

#❓how-to-get-help
4. If your question has not been answered for a minimum of 15 minutes, you may use the <@&286206848099549185> tag once. Please do not try to bump your question using this ping unnecessarily. Do not abuse this ping. Do not individually ping users with the Helpers tag without their express permission.

surreal meadow
#

LOL pinged helpers again to explain what not to do

#

kinda funny

fickle cliff
#

oops sorry for that

dawn galleon
gritty pine
#

is the default index of a radical 2?

oak chasm
#

Yes, if you don't see a number, it's 2.

ocean sealBOT
#

Chai T. Rex

gritty pine
#

OOOH finally i understand

#

its like saying 1/2

fringe robin
gritty pine
#

2 is the index of the radical

gritty pine
oak chasm
#

No problem.

fringe robin
fringe robin
ionic jewel
#

i feel this this is one of those integrals where you have to turn one or two of your sin^2(x) into 1-cos^2(x) so you can u-sub and solve

fringe robin
#

i did cos^6 x divided both num and den

#

and i just got ans

#

thanks

dense tulip
#

Hey guys so this is sorta like a theoretical question that came up in my mind that I need help with

#

because I have the idea

#

that it's probably wrong in some way

#

so basically using the pythagorean identity

#

sin^2+ cos^2 = 1

#

if we simply take the square root of both sides

#

we get

#

sin+cos=1

surreal meadow
#

nope

dense tulip
#

is that not correct?

surreal meadow
#

$\sqrt{x^2 + y^2}\neq x+y$

ocean sealBOT
#

maximo

dense tulip
#

ohhh really?

surreal meadow
#

take x = 2 y = 3

dense tulip
#

man I didn't realize that

dense tulip
surreal meadow
#

2 + 3 = 5, 4 + 9 = 13

#

sqrt(13) =/= 5

dense tulip
#

ohh I see

#

that's so weird

#

though

#

it intuitively sort of makes sense

surreal meadow
#

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

#

its called freshman's dream

dense tulip
#

but I guess mathematics is all about discovering the fundamental truths vs intuition

surreal meadow
#

yup

dense tulip
#

so is that the same as the sqrt

#

thing I was talking about earlier?

surreal meadow
#

you basically did the inverse

dense tulip
#

oh I see

#

cause like I guess I just took sqrt of sin^2 as sin and cos^2 as cosine and just jammed them

#

together

#

lol

#

ok thank you so much for helping me realize this flaw in my reasoning!

#

I'm legit doing AP Calc stuff and I tried applying this and failed

surreal meadow
#

np 👍🏻

#

haha i forget rules all the time

#

in an ap calc test i had to work back on whether $x^ax^b = x^{a+b}$ or not

ocean sealBOT
#

maximo

dense tulip
#

ohh lol

#

nice

#

yeah I like the fact we can keep rederiving

#

things in math

#

its really cool

surreal meadow
#

nono

#

i mean like i literally forgot

dense tulip
#

oh about the rule

#

yea happens to me

surreal meadow
#

and yeah i derived it quickly again cause its obvious

dense tulip
#

as well

surreal meadow
#

but yeah lmfao

dense tulip
#

thx for the help dude

#

appreciate it

surreal meadow
#

np

dense tulip
#

hopefully physics is actually not harder

#

than calc

#

liek alg trig based

#

physics

surreal meadow
#

it's different i'd say

#

theres a bit more memorization and the actual applications can be tricky

#

but its a different kind of difficult

dense tulip
#

ah ok

#

so like more problem solving?

surreal meadow
#

well yes, but i'd also call math problem solving

#

it's a more constrained type of problem solving, you have to be more careful of the rules and definitions as well as applications

dense tulip
#

i see

#

I"m always really bad at applications like in terms of definitions

#

that are hard to place

paper minnow
#

Is it necessary to write a double or triple integral when talking about a surface or volume if you've made it clear and are consistent all the way through? Just wondering in case I accidentally write it in a test paper or exam

surreal meadow
#

I'd assume so. you can always just give an integral a name like $I=\iint_Df(x,y)dA$

ocean sealBOT
#

maximo

surreal meadow
#

so you don't have to write the whole thing over and over again

paper minnow
#

This is just a pure notation thing, just can't be fucked writing double or triple integrals is all. So in a test or exam paper, I can write $\int_{\Sigma}dA$ instead of $\iint_{\Sigma}dA$ if I've made it very clear that $\Sigma$ is a surface?

ocean sealBOT
surreal meadow
#

i think they mean different things, or that it might not even compute, but I can understand your pain

#

its sort of like writing $\Sigma_DdA$ instead of $\iint_DdA$

ocean sealBOT
#

maximo

topaz scaffold
surreal meadow
#

just mean different things yknow?

paper minnow
#

yeah, I keep seeing the generalized Stoke's theorem and I'm like "😩 Why can't I just write a surface integral with one integral sign instead of two? it would be so much easier"

#

oh, I think I see the potential confusion though, if it gets construed for something in measure theory or statistics, right?

surreal meadow
#

that’s just my thoughts, and i’ve only recently learned about this stuff, so my views may be horribly wrong. there might be a way to avoid more pointless writing though

gray oxide
#

What is f'(2)

If f(x) = 2sqrt(x)

#

This is my anwer so far but it's wrong so pls tell me where I went wrong

surreal meadow
#

do you know the power rule?

wild marten
ocean sealBOT
#

Lester

glass lichen
#

f'(2), to actually answer the question you asked... is the derivative of f(x) evaluated at x=2

gray oxide
#

This is what I did but it's not wrong

#

When you derivate a constant doesn't that become zero?

gray isle
#

Um that is extremely bad notation that makes it almost impossible to decipher

gray oxide
#

Oh sorry I'll try to rewrite it

#

Gimme a sec

gray oxide
gray isle
#

Yes

#

With appropriate use of = signs

#

the first part of that pic is already nonsense

gray oxide
#

Idk if this is better but hopefully it is

gritty pine
#

can any tell me how he got sqrt(5^2) * sqrt(2^3?)

gray isle
#

Ok your work is still nonsense

gray oxide
#

Sick

gritty pine
#

he just took the M.C.M to get the 6sqrt

gray isle
#

The first thing you wrote is literally already wrong

gray oxide
#

So you can't take out the constant?

gray isle
#

Not like that

#

you should be starting with
$$f(x) = 2\sqrt{x}$$

gray oxide
#

But there are examples where that is the right move why is it wrong here? Is it becuase its an multiplication?

ocean sealBOT
#

ℝamonov

gray oxide
gray isle
#

No you didn't

#

for some reason you included the ' at the very start

#

Indicating the derivative was already 2sqrt(x)

#

and then for some reason erased the 2 from existence

gray oxide
gray isle
#

and then said more stuff that wasn't equal was equal

gray oxide
#

I wrote the f'(x) to indicate that I'm going to do the derivate of the function in an actual exam I would have to write more correct but here I already know what f(x) is equal to so I felt that I didn't need to be "grammatically" correct

#

But if I did something wrong then my bad

gray isle
#

you do, otherwise people won't know what your talking about

#

and assume you have no idea what you're doing

#

and won't know whether you actually understand or not

gray oxide
#

But I did write what f(x) is and what f'(2) is

#

But I see your point

#

I can't expect ppl to know what I'm thinking

#

Sorry

#

Ok so do you want me to rewrite it? And then continue from there?

gray isle
#

$f(x) = 2\sqrt{x} \
f'(x) = \dv{x}(2\sqrt{x}) =2 \dv{x}\sqrt{x}$

ocean sealBOT
#

ℝamonov

gray isle
#

start with something like that

gray oxide
#

Is that d/dx?

dreamy crow
#

wrong pic?

gray oxide
#

No, that's the derivates definition

gray isle
#

d/dx is a derivative operator

gray oxide
#

At least that's whats it's called in my language

gray isle
#

what you posted is the limit definition of the derivative

gray oxide
#

And what is the d/dx?

gray isle
#

d/dx is a derivative operator

#

d/dx sqrt(x)
Is the derivative of sqrt(x) wrt x

devout sigil
#

@gray oxide d/dx is the gradient function of a function... when question is asking for d/dx(2sqrtx) it means find the gradient of the curve 2sqrtx

gray isle
#

$f'(x) = \dv{x} f(x)$

ocean sealBOT
#

ℝamonov

devout sigil
#

Also u know power rule?

gray oxide
#

I think so

#

I'll search up what it means quickly cuz I don't know the English terms

dreamy crow
#

this

#

@gray oxide

devout sigil
#

Ok, u want to find a way to get the value of n

gray oxide
#

Yea

devout sigil
#

What is ur answer for n?

gray oxide
#

On the picture?

devout sigil
#

Yes but now u have 2[d/dx (√x)] right?

gray oxide
#

Yea

devout sigil
#

If u get what @gray isle said

#

So we can sub this into the picture, √x=x to the power of n

gray oxide
#

Oh

devout sigil
#

Now can u tell me what is n?

gray oxide
#

N would be 1/2

devout sigil
#

Yep!

#

And n-1 would be 1/2-1=-1/2 right?

gray oxide
#

Ok so aren't we supposed to derivate that? Or was that not a rewriting but a derivation?

#

Oh ye

#

So x^-1/2 = 1/sqrt(x)

devout sigil
#

nx^(n-1) is the derivative, for x^n it’s still the function itself and is not yet differentiated

#

Yes u are right

dreamy crow
gray oxide
#

Yes

gray oxide
#

But why wouldn't you take out the 2?

devout sigil
#

Ok when u take a constant like 2 out, always live it there till u fully simplified ur derivative

dreamy crow
#

becuase it is not a constant like you said

gray oxide
devout sigil
#

Huh? 2 is a constant

dreamy crow
#

well not in the way he thinks it is

gray oxide
#

I'm thinking that it has no value after it is derivated

#

Becuase it is a constant it doesn't have a changing value

gray isle
#

the 2 is being multiplied to sqrt(x)

devout sigil
#

No, if u know the scalar multiple rule, we can take it out such that 2 d/dx(x^n) is what we have simplified to

gray isle
#

the 2 isn't by itself here

gray oxide
devout sigil
#

U can factor it out to differentiate the variable

#

But u must not remove it

gray isle
#

the derivative of a constant is 0

devout sigil
#

Because it is part of the equation

gray isle
#

however you aren't differentiating a constant here

dreamy crow
#

that was what i was trying to say

gray oxide
#

You factored it out?

devout sigil
#

9 is a constant, 9x is not a constant, 9 √x is not a constant

#

Yes I did

gray oxide
#

Oooooooooh

#

Lmao right you derivate the X in 9x but you leave the 9 out of it

devout sigil
#

Yes

gray oxide
#

I get it now hahahahaha

devout sigil
#

So if I have d/dx(9x) I can say it’s the same as 9d/dx (x)

#

Nice

gray oxide
#

Ok thank you now I know why I got the wrong answer

devout sigil
#

No problem, I’m glad I have been able to help

gray oxide
#

But if it wouldn't be to much I have one last question

devout sigil
#

Good luck!

gray oxide
#

Can you prove that the 9 in 9x is wrong to be derivated? Can you use logic to show how it is wrong to do that or is this one of those rules that it just is like that?

gray isle
#

depends on what you're doing

devout sigil
#

Scalar multiple rule: d/dx(k•f(x))=k•d/dx(f(x)) where k is a constant

#

That should be in math textbooks?

gray oxide
#

I don't have the d/dx but I do have this

gray isle
#

Usually somehow erasing something from existence will not be valid

gray oxide
obsidian cave
devout sigil
#

Because if u differentiate the constant together with ur function u would probably end up with 0 right?

gray isle
#

you could consider 9x as the sum of 9 xs

devout sigil
#

Thus it doesn’t make sense. If I have any two functions let’s say y=4x-1 and y=2x³+x, if u differentiate the constant together u will get dy/dx=0. Which is illogical because the functions are different

#

This is by assuming u applied product rule

gray isle
#

9x = x + x + x + x + x + x + x + x + x

dreamy crow
#

u have the rule in your page just saying

gray isle
#

there is no way to properly justify erasing the 9 from existence in d/dx 9x
To get just d/dx x

devout sigil
gray oxide
#

But yes thank you @devout sigil @gray isle @dreamy crow @obsidian cave

#

I appreciate it really I do

devout sigil
#

Example y=8x² and y=9x². dy/dx of first function is 8(2x), where dy/dx of second function is 9(2x). This shows that if the functions are similar, just differing in their constant product value, the gradient function is proportional to it.

gray oxide
#

Alrighty thank you imma leave this channel open now cya

devout sigil
#

Np, have fun learning math 🙂

surreal meadow
#

if you understand the power rule $(f(x)\cdot g(x))'=f(x)\cdot g'(x) + f'(x)\cdot g(x)$ then the constant rule should be easy to remember

ocean sealBOT
#

maximo

gray oxide
#

It's fun when you understand it :)

surreal meadow
#

$(c\cdot f(x))' = c'\cdot f(x) + f'(x)\cdot c$

ocean sealBOT
#

maximo

surreal meadow
#

since the derivative of a constant is 0, you can simplify this to 0*f(x) + f'(x)*c

#

so c*f'(x)

gray oxide
surreal meadow
#

exactly

#

so you get 0 * f(x) + c * f'(x)

#

which means you're only left with c * f'(x)

#

meaning that (c * f(x))' = c * (f(x))' = c * f'(x)

gray oxide
#

Are you using the derivate definition here?

#

Nvm there is no division

dreamy crow
#

callidus do you know what the derivitve represents?

gray oxide
#

Change

dreamy crow
#

rate of change exactly

alpine sable
#

Questions I have none.

gray oxide
surreal meadow
#

think about it for just f(x)
f(x) = 1 * f(x)
f'(x) = 1 * f'(x)

dreamy crow
#

lmao

surreal meadow
#

and using the product rule

#

(1 * f(x))' = 1 * f'(x) + 1' * f(x) = 1 * f'(x) + 0 * f(x) = 1 * f'(x)

dreamy crow
#

do you understand now why you cant take the multiplier out or do you need a more visual proof?

gray oxide
dreamy crow
#

nah its easy

#

i can show you now

#

tell me what does the derivitve represent

gray oxide
#

Alright

gray oxide
dreamy crow
#

exactly

#

so let me show you a hypothethical situation lets say we have a function 0x^2 and a function 12x^2

#

if we were to cross out the multipliers

#

we would get that both of the functions change at a rate of 2x

#

but

#

if we graph this

#

we can clearly see that that is not the case

gray oxide
#

Yep

dreamy crow
#

do you understand now?

gray oxide
#

Yea I do get that they are not the same

dreamy crow
#

exactly 0x^2 is a function that constantly stays at 0

#

therfore its rate of change is 0

gray oxide
#

Yes

dreamy crow
#

but 12x^2 does change at some speed

#

but if we were to omit the multiplier like you did we would end up saying that both functions change at the same speed

#

which the clearly dont

#

do you understand now?

gray oxide
#

I understand that with the multipliers they change differently but without the multipliers they change the same is that right so far?

dreamy crow
#

yes if you were to take out the multipliers you would be saying that a functions which y value constantly stays at 0 is changing at the same speed as a function whichs y value does actually increase which is nonsencical

woeful remnant
#

Would someone know the answer to this question. "The mathematical operation known as addition is modeled after what?"

surreal meadow
#

the channel is occupied @woeful remnant , please go to another channel

woeful remnant
#

Oops sorry

dreamy crow
#

@gray oxide do you understand my explination

gray oxide
#

Yes I do get it

#

But

#

Why do we take out the whole coefficient first?

dreamy crow
#

wdym

gray oxide
#

In your example

#

You took out the 0 and 12

surreal meadow
#

you don't

#

it's just for the example

gray oxide
#

To show that the function wouldn't be the same after you take it out

dreamy crow
#

yes im trying to prove that taking it out would be wrong

#

and why you leave it in

#

as you asked

surreal meadow
#

@gray oxide what exactly are you having trouble comprehending?

gray oxide
#

The thing is I actually dont know lmao so I'm gonna go back an read untill I don't know what I'm reading anymore gimme a sec

dreamy crow
#

okay take your time its fine

gray oxide
#

$f(x) = 2\sqrt{x}
f'(x) = \dv{x}(2\sqrt{x}) =2 \dv{x}\sqrt{x}$

ocean sealBOT
#

!callidus

gray oxide
#

When the 2 was taking out of the function and derivated

#

That was my original problem

surreal meadow
dreamy crow
#

ah okay

surreal meadow
#

you can leave it in

#

you can take it out

#

it doesn't affect the result in the end

gray oxide
#

Becuase I cannot derivate the 2, but only the sqrt(X) part?

surreal meadow
#

what do you mean

#

you can derive a constant

#

$\frac{d}{dx}c = 0$

ocean sealBOT
#

maximo

surreal meadow
#

the rate of change of a constant is 0

gray oxide
#

Yes

#

But seeeeeeee

#

I'm really sorry

surreal meadow
#

don't be

dreamy crow
#

its okay

gray oxide
#

But 0* sqrt(x) = 0 right?

surreal meadow
#

yes

dreamy crow
#

yes

surreal meadow
#

but look back at what i sent

gray oxide
#

Hmmmm

surreal meadow
#

there is a rule for the product of derivatives

dreamy crow
#

okay let me show you visually why the rate of change of a constant is 0

gray oxide
#

No I get that

surreal meadow
#

he understands that testing

#

do you understand the power rule call?

gray oxide
#

Yes

surreal meadow
#

ok

#

now look at how it works when we apply it to a constant and a function

gray oxide
dreamy crow
#

yea

gray oxide
#

Ok

surreal meadow
#

so for example, if c = 2

gray oxide
#

Yep

surreal meadow
#

(2 * f(x))' = 2' * f(x) + f'(x) * 2

#

and the derivative of 2 is...?

gray oxide
#

0

surreal meadow
#

so we get

#

0 * f(x) + 2 * f'(x)

#

= 2f'(x)

gray oxide
#

So ur using the product rule?

#

This thing wiat

surreal meadow
#

we use the product rule to show that constants can be "moved" outside of the derivative without issue

gray oxide
surreal meadow
#

that one

#

yes

dreamy crow
#

yes

gray oxide
#

Ok sick

#

Thank you very much

dreamy crow
#

okay do you understand now?

gray oxide
#

Yes fully I feel much more calmer about my exam hopefully you guys get rtx 3090s so you can sli them

dreamy crow
#

yes :D

gray oxide
#

Lmao alright srsly tho thx a lot cya

#

I'll be back tmrw for another mission to understand the maffs

dreamy crow
#

no problem :D

#

okay

inner sequoia
#

why does subtracting from x shift the graph right

surreal meadow
#

because if we subtract 1, the new x = 1 is the old x = 0

ionic jewel
#

because the y value previously graphed at each point is now graphed at each (x-h) which is left

inner sequoia
#

and lets say 2x is 1

#

so if x is 1 then the point is at (1,2)

#

but if i subtract 1 from x

#

then (1,2,) becomes (0,0)?

surreal meadow
#

yes, if you had 2(x-1), x = 1 would now point to the old x = 0 value

inner sequoia
#

bcs if f(x)=2x

#

then f(x-1) will still equal 2x?

surreal meadow
#

because if f(x) = 2x, and g(x) = 2(x-1), then f(0) = g(1), f(1) = g(2), f(n) = g(n+1)

inner sequoia
#

why does it change the axis

surreal meadow
#

wdym?

inner sequoia
#

wait

#

f(x) = 3x

#

x = 4

#

f(4) = 12

surreal meadow
#

yes

inner sequoia
#

g(x-1)= what

surreal meadow
#

g(x) = 3(x-1)

#

or even g(x) = f(x-1)

inner sequoia
#

why is it 3(x-1)

surreal meadow
#

i thought you were following what I said above

inner sequoia
#

nope

surreal meadow
#

we just describe a function g as the shift of f(x) right 1 unit

inner sequoia
#

why would addition shift the graph left

surreal meadow
#

that's what I've been explaining

#

take f(x) = 3x

#

and g(x) = 3(x-1)

inner sequoia
#

ok

surreal meadow
#

f(0) = 3(0)

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g(1) = 3(1 - 1) = 3(0)

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so f(0) = g(1)

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same thing happens for f(1) and g(2)

inner sequoia
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g(1)=3(1-1) which is 3(0) which is 0

surreal meadow
#

yes

inner sequoia
#

so g(1)=0

surreal meadow
#

which coincides with f(0)

inner sequoia
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so g(1)=(f(0)

surreal meadow
#

since we're subtracting 1 from x, its as if we're shifting the whole plane to the left 1

inner sequoia
#

ah

surreal meadow
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or moving the function to the right 1

inner sequoia
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bcs x is moving left

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but the function stays the same

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so the function increases

surreal meadow
#

yes, that's how they describe transformations in linear algebra too

inner sequoia
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or moves right

surreal meadow
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instead of moving a function they move the plane

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so instead of moving the function/curve to the right, think of it as moving the plane to the left

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since every x value is now instead x-1

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so x=0 is now in the position of 0-1 = -1, 1 is in the position 1-1 =0

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and so on

inner sequoia
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ok so if
f(x) = 4x
x=4
and g(x) = 4(x-3)
then f(x)=16
and g(x)=4

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wait

inner sequoia
surreal meadow
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right, think of g(x) as g(x) = f(x-1)

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so for every single x

surreal meadow
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g(x) is actually f(x-1)

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yes that's right

inner sequoia
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but y = 4 now instead of 16

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wouldnt that mean it was shifted left

surreal meadow
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no

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the opposite

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since the sope is 4

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a higher y comes at a higher x

inner sequoia
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lower y = lower x

surreal meadow
#

yes

inner sequoia
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but g(x) = 4 is a lower y than f(x)=16

surreal meadow
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exactly

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wait im confused

inner sequoia
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same

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lemme try again

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f(x)=1x

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g(x)=f(x-2)

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if x = 2

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then f(2)=2

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g(2)=f(2-2)

surreal meadow
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well the thing here is that the function is sort of shifted down as well

inner sequoia
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g(2)=f(0)

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but what does g(2)=f(0) mean?

surreal meadow
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look at this graph

golden nymph
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the image of g at 2 is the same as the image of f at 0

surreal meadow
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you'll see the points line up with each other on the x-axis since they are all taken at x=3

inner sequoia
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oh wait

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if f(0) = g(2)

surreal meadow
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that's not the case

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g(2) = f(0)

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not the other way around

inner sequoia
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g(2)=f(0)

golden nymph
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wot

surreal meadow
golden nymph
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ok

inner sequoia
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so if g(2) = f(0)

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wiat