#help-13

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cedar kilnBOT
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cursive cedar
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What's the strategy for this?
Completing the square with 3 variables?

cedar kilnBOT
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@cursive cedar Has your question been resolved?

tranquil oracle
cursive cedar
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I'm doing d right now

tranquil oracle
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d doesnt seem to be a positive combination of squares

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Plug in 1 1 1

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hmm looks like negative squares are allowed?

cursive cedar
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I found a solution

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

tranquil oracle
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Theres a strategy involving eigenvalue decomposition but that might be overkill

cursive cedar
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How

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This is that topic

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We're doing linear algebra

tranquil oracle
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Write quadratic form as v^T A v for some symmetric matrix A

cursive cedar
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The symmetric matrix

tranquil oracle
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Diagonalize A

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Get orthogonal matrix Q:
v^T Q^T D Qv

Read answer from matrix

cursive cedar
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A = [3 -3 -9; -3 -2 -1; -9 -1 7]

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Orthogonally diagonalise A to get Q?

tranquil oracle
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Yeah

cursive cedar
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And then we look at the columns of Q?

cedar kilnBOT
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cedar kilnBOT
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rancid phoenix
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I need help with both of these graphing problems, for both of these we need to find the domain, range, x-value intervals on which f(x) is decreasing, x-value intervals on which f(x) is increasing, x-value intervals on which f(x) is constant, and x value relative maximum and minimum

high bridge
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um, which of those do you actually need help with?

rancid phoenix
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Both

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But we can start first one

high bridge
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all of those? like domain, range stuff?

rancid phoenix
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Ye

high bridge
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ok sure yeah

rancid phoenix
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Alr

high bridge
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can you tell me what a domain of a funtion is?

rancid phoenix
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A graph that shows all x values

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As input

high bridge
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not accurate enough

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the domain of a function is all the x values that is allowed by the function

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for example: if you have f(x)=x

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then the domain is x is an element of the reals

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another example: if you have f(x)=1/x

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then the domain is x does not equal to 0 and x is an element of the reals

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x does not equal to 0 because f(0)=1/0 is not allowed

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knowing this, can you tell me what is the domain of funtion 1?

rancid phoenix
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f(x) = -6

high bridge
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?

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why did you think that/

rancid phoenix
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Because theres a arching point where its above the x value -6

high bridge
winged tinsel
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hello

high bridge
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if you want help to to a different open channel

rancid phoenix
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f(x) = -6,-4,1 and 3

high bridge
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again the domain is ALLLLLLLLLLLL the values x CAN be

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x is not ONLY -6 -4 1 and 3 in the first function

rancid phoenix
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So its everything?

high bridge
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define everything

rancid phoenix
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Is it all x values like infinite and negative inf

high bridge
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ok so you did not look at my examples at all

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the correct term is x is an element of the reals

rancid phoenix
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What is reals?

high bridge
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you know real numbers>?

rancid phoenix
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Oh

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Ye

high bridge
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basically saying that x is an element of the reals, you are saying x can be any real numbers

rancid phoenix
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I see

high bridge
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written down on paper it looks like this:

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x ∈ R

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the central symbol means "is an element of"

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and the capital R means all Real numbers

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alright range

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like how domain means ALL X values allowed

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range means ALL Y values

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can you tell me what the range is for the first function?

rancid phoenix
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y ∈ R

high bridge
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um

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now is that true?

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where on the graph do you see y can be... let's say 4?

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is there anywhere on the graph where y is 4?

rancid phoenix
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No

high bridge
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so y is not just an element of the reals

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a critical question to ask yourself when finding the range:

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can you see a highest point/ lowest point on the function?

winged tinsel
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please solve this question.

high bridge
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Suryansh please open another channel instead of posting another problem here

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another open channel

rancid phoenix
high bridge
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there can be a max of 1 high point and 1 low point, however, there could be none of those accordingly

rancid phoenix
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I think theres atleast one high and one low

high bridge
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nonono

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max one high and max 1 low

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could be none

rancid phoenix
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Oh

high bridge
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can you tell me, where do you think is the highest point on the function?

rancid phoenix
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3

high bridge
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good

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now is there a lowest point on the function?

rancid phoenix
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No?

tropic oxide
cedar kilnBOT
high bridge
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so now you have figured out that the highest point of y-value is 3 and there is no lowest point

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you can conclude that all y-values must be (put an inequality sign here) 3

rancid phoenix
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Alr

high bridge
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I am asking you to put an inequality sign

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what sign should you put there?

rancid phoenix
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y ≠ 3

high bridge
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also I need to leave after 19 minutes, better make it quick

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um

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why is y not equal to 3?

rancid phoenix
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i cant make inequality sign

high bridge
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tell me what inequality sign you think is there?

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y (sign) 3

rancid phoenix
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Greater sign underlined

high bridge
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that is called greater or equal sign

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so you are saying y>=3?

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well 4 is >= 3

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is 4 a part of the range?

rancid phoenix
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No

high bridge
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so greater or equal sign is not correct

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try again, which sign do you put?

rancid phoenix
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It would be <=

high bridge
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exactly

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less or equal sign

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there you have it

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the range of function 1 is y≤3

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next: where is f(x) decreasing

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well that is simple, where is f(x) going down

rancid phoenix
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-5

high bridge
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now now

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it is not going to be a point

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it is going to be a range of values

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where is f(x) going down you go left to right

rancid phoenix
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-6,-4

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I gtg

high bridge
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oops sorry I need to go

rancid phoenix
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Oh

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Its fine

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Ty

winged tinsel
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anyone please clear my doubt.

random dirge
winged tinsel
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i am unable to start a new channel, i am new on discord. please help me

random dirge
cedar kilnBOT
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@rancid phoenix Has your question been resolved?

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gilded frigate
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how can i set up the integral to find its volume?

open grove
wraith daggerBOT
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@open grove

gilded frigate
open grove
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And then use that as your f(x)

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Find a and b by finding the zeroes of y = 2x^2 - 2

gilded frigate
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how can we find b and h to get the area though

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@open grove

open grove
gilded frigate
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what

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yeah i can find a and b by finding its zeroes

gilded frigate
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but how can i find base and height of the cross section so that i can find the area of the triangle

open grove
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Then use this to find the height

gilded frigate
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so the lenght is basically the y value?

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OH

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the parabola is bounded by the x axis

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and its base runs from a to b

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if i find a to b and its distance

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i get its base

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and then using its base i get its height

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then compute for the area of the triangle

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then integrate from a to b

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and thats it?

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@open grove

gilded frigate
open grove
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These are the cross sections

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The distance between a and b is irrelevant

gilded frigate
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a

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hmm

gilded frigate
open grove
gilded frigate
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so its dx???

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oh no

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UH

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is the base length

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2x^2 - 2

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@open grove

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ohh

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then i just multiply by 2

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and find area

open grove
gilded frigate
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i think i got it

open grove
cedar kilnBOT
gilded frigate
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ty

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.close

cedar kilnBOT
#
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open grove
cedar kilnBOT
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queen stirrup
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Let f : R → R be a twice differentiable function such that f ′′ ≥ 0. Prove that f is
bounded below.

queen stirrup
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I tried to do a proof by contradiction, by looking at a monotone sequence x_n such that f(x_n)<-n

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i got kinda far but no results

untold marten
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Are you sure it's ≥ and not >

queen stirrup
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its >=

untold marten
queen stirrup
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i wonder if anything would change if f'' > 0

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how to prove it ?

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there might be a counterexample

ancient cliff
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i don't think there is

queen stirrup
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hm

untold marten
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Yea I think the statement is untrue even for f" > 0

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Because f' can be a function that goes from like -2 to -1, and be continuously increasing

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In which case f">0

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But f will tumble down to negative infinity

untold marten
queen stirrup
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this is what i was thinking about too

queen stirrup
untold marten
queen stirrup
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then i checked -ln(|x|) but its not differentiable at 0

untold marten
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Think about f'(x) = arctan(x) - 10

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f" > 0

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But f(x) will have no lower bound

queen stirrup
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f(x) has a lower bound

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0

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plotted integral of arctan x - 10 on desmos

untold marten
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Send it here

queen stirrup
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@untold marten

untold marten
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You put f(x) = arctan x

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I was saying arctan x - 10

queen stirrup
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oh

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hmm you're right

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smart

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how do you think of examples like this

untold marten
queen stirrup
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i only thought of ln x

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like how do you think of the appropriate functions

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arctan x would never come to me

untold marten
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lnx isn't bounded above

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We wanted a function that is bounded within two constants

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Arctan(x) is usually the best go to

queen stirrup
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right

queen stirrup
untold marten
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Then move it up or down

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Based on if u want it fully negative or fully positive or intersecting x axis

queen stirrup
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right

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ok thanks a lot!

untold marten
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You're welcome

queen stirrup
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:)

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.close

cedar kilnBOT
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cedar kilnBOT
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dense bane
cedar kilnBOT
dense bane
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guys ion even know how to begin this 😭

opal hinge
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sub $3^x=u$

wraith daggerBOT
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Alexis_Fx

twilit escarp
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And in case you wonder for $3^{2x}$ its the same as $(3^x)^2$

wraith daggerBOT
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msg db "YakuBros", 0

dense bane
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whaa de heeel

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so it's something to do with making them all 3^x?

twilit escarp
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Yep and then you make the sub that Alexis suggested

dense bane
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OHH

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(u-3)(u+1)

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u = 3 and -1?

sullen hedge
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what did you make u equal to?

dense bane
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3^x

sullen hedge
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nice, so now solve the equation for that

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$3^x = 3 \text{ and } 3^x = -1$

wraith daggerBOT
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joseph

dense bane
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oh wait it's not finished

sullen hedge
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yeah, since we did a substitution, we need to revert

dense bane
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so I sub one of them back in

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3^2 - 2(3) - 3 = 0

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wait

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i'm lost

sullen hedge
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okay so you had u = 3 and u = -1

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right?

dense bane
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yes

sullen hedge
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but we also said $u = 3^x$

wraith daggerBOT
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joseph

sullen hedge
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and the original question is to find x

dense bane
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3^x = 3

sullen hedge
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yep

dense bane
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and x=1?

sullen hedge
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yes

dense bane
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ohhh I see

sullen hedge
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nice

dense bane
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thank you!!

sullen hedge
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now what about the 2nd solution?

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3^x = -1

dense bane
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uh

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-3^0

sullen hedge
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lol, so its not really possible is it

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3 raised to any real number can not be a negative

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so x = 1 is your only solution

dense bane
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ahh okay

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thank you!!

sullen hedge
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np

dense bane
#

.close

cedar kilnBOT
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lime ether
#

we need to prove that the func is bounded in the intreval (0,pi/2) now i understand that the func is countious on all of R excpect where sinx /= 0 so at zero so we need to check the right hand limit of the func as x approches

lime ether
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that is what the teacher wrote in the sol why did he wrote that the func value of zero its equal to 1

slender ginkgo
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F(x) is continuous at 0

lime ether
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but if we plug 0 the func isnt defined

tropic oxide
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F(0) [capital F] is defined, explicitly.

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however $\lim_{x \to 0} \frac{2x^2+x}{\sin(x)}$ can be calculated!

wraith daggerBOT
slender ginkgo
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approximation 😎

lime ether
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yeah i know its equal to 1

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that isnt the problem we need to prove that f(x) is countious on the interval so we can use the extreme val therom

slender ginkgo
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F(x) is continuous on [0, pi/2]

lime ether
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yes

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i understand that

slender ginkgo
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so u can use evt on F(x)

lime ether
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ok

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i agree

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but what about f(x)

slender ginkgo
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f(x) has a hole on [0, pi/2] so it is not continuous at x = 0

tropic oxide
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f(x) is the restriction of F(x) to (0, pi/2)

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the restriction of a bounded function is bounded

lime ether
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what to u mean by restriction

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u mean that F(x) = f(x) on the interval (0,pi/2)

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?

royal finch
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The point is that if you can show that F(x) is bounded, then deleting two points to get f(x), it is still going to be bounded.

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The extreme value theorem is a bit stronger than what you actually need since it also guarantees that the mina and maxima are achieved, but you only care about boundedness.

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This is why you can start on a closed and bounded set, and shrink it down to an open set and still get the result you care about from the EVT

cedar kilnBOT
#

@lime ether Has your question been resolved?

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tacit aurora
#

does anyone know a good video that explains pulleys and newtons laws?

tacit aurora
#

i already tried googling this lol

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its just that most of what i saw until now only touched some laws or more laws or used friction

dire geode
tacit aurora
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a video about pulleys with only the 3 motion laws without slants and slopes

dire geode
tacit aurora
#

less of a video with example practice more about explaining generally

dire geode
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explaining what generally ?

dire geode
tacit aurora
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f = ma

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for each movement one that counteracts it

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and if sigma f is 0 speed is const

tacit aurora
flint cape
tacit aurora
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yeah those

flint cape
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(which aren't in the right order)

tacit aurora
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ik

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idr the order

flint cape
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(the order you've listed is 2nd, 3rd, 1st)

tacit aurora
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i need to get a hang of this in a few hours

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but with the practices we got i just dont understand enough to even start

cedar kilnBOT
#

@tacit aurora Has your question been resolved?

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charred oriole
#

Hey guys, idk if I'm being stupid but I don't know how this is wrong

charred oriole
#

It says a discount, so I did 400 - 35 = 365, then I took 20% of 365 and added that onto the total because it says discount of 35 and 20% more

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But apparently the answer is 515? I don't understand

obtuse ice
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So 20% more of the original cost would be $400 multiplied by 1.20 which is 120%. Then add $35 to that you get the price it was listed as before the $35 discount if I’m correct

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Yeah cuz 400 times 1.2 is 480+35=515

charred oriole
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But why adding 35?

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I dont understand because it says discount

obtuse ice
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Because it says after giving a discount of 35 the price is now 20 percent higher than originally

charred oriole
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Now I'm even more confused. My understanding is that if you take a discount, you're subtracting by however much that amount is

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Not adding it

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That's marking it up

obtuse ice
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It could also be written as x-$35=$400x1.2

wraith daggerBOT
charred oriole
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Oh writing it as an equation is what I should've done

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Fuck

charred oriole
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So don't feel bad, it's just how they like to write their stupid word problems

obtuse ice
#

Yeah verbal exercises can be so confusing

charred oriole
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Yeah next time im just writing it as an equation

obtuse ice
#

Yep it usually helps

charred oriole
#

They love to do this bullshit and it pisses me off

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ty for the help

#

.close

cedar kilnBOT
#
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cedar kilnBOT
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young shard
#

Am i wrong to think that this process is mistaken? my proffesor seems to have taken -i * i to be equal -1 for simplification, but isn't it actually 1? what am i missing?

young shard
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i fail to see where the (-1) comes from at all in -3 (-1)

twilit escarp
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-3*i²

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(-3)(-1) = 3

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he probably did it this way

split ice
#

this, because 2-i is actually (2) + (-1)i. so (3)i * (-1)*i = (3)(-1)(i^2) = 3 as msg said

jagged flicker
young shard
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right it results in 3, but how do you arrive at that 13 at the end? 10 - 3 = 7 so you get 7 on the real side of the complex number

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am i missing a sign somewhere?

mental trail
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10+3 = 13

jagged flicker
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then 10 + 3 = 13

young shard
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arent you supposed to substract the number you get? according to (a.c) - (b.d) for the real part in complex multiplication

mental trail
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It's already done!!!

mental trail
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It's the -1 you get from i²

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ac + i²bd = ac - bd

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Then d = -1

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So ac + b

young shard
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oh i see i think, i´ll go over it for a bit but i see where i was going wrong

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.close

cedar kilnBOT
#
Channel closed

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young shard
#

.reopen

cedar kilnBOT
#

young shard
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sorry to the person typing i need to figure out something else

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i passed it through wolfram alpha and it gave me the result i got?

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this should have given me 13 instead with the 3 adding instead of subtracting, did i type it wrong?

split ice
#

,w (5+3i)(2-i)

split ice
#

as a sanity check

young shard
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i saw that too

slender ginkgo
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there are 4 terms

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after distributing

split ice
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doing partial FOIL, you should get 5*2 + (3i)(-i)

slender ginkgo
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(without having yet combined liked terms)

split ice
#

the formula takes i * i out of this, and so the rule is 5*2 - 3*(-1)

slender ginkgo
split ice
#

considering the real part here*

slender ginkgo
#

oh right

split ice
#

what you seem to be doing is using the formula, but adding an extra i*i in; the formula takes care of this by doing subtraction

young shard
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if it was 3i * i then it would be -3 but since you have -i instead then that has to affect something right?

split ice
#

i think it's easier to explain if you forget about the formula for a sec, and just try FOIL on (5+3i)(2-i)

young shard
#

i'm not familiarized with FOIL, i assume you mean the distributive property? i think it's something like that from what i've seen

#

could you walk me through it?

split ice
#

yes sorry, i do mean distributive property

#

treating i as a variable for a second, how would you multiply the binomials?

young shard
#

10 - 5i + 6i - 3i^2

flat mica
#

first-outer-inner-last it's a mnemonic

split ice
#

this, just another way to multiply binomials

flat mica
#

personally I like doing "FIOL" better

young shard
#

no wait that yields a different result though?

split ice
#

now, let's rearrange this as (10 - 3i^2) + (6i - 5i)

young shard
#

oh yes

split ice
#

this would actually give us 13 + i so it works out :) can you see why?

young shard
#

yes, but i still don´t see what was leading me astray in the first method, this way is much clearer so i might stick to it but i wouldn´t want to not know how to do it the usual way

#

thanks for explaining so far by the way

split ice
#

it's a little confusing because there's a subtle difference between the formula and the binomial expansion

#

firstly, to clarify, im gonna write it as (10 + (-3)i^2) + (6i - 5i). i.e. we are adding the terms

#

if you do the binomial expansion on two arbitrary numbers, say $(a+bi)(c+di),$ you will always end up with $$\big(ac + (bd)i^2\big) + \big((bc)i + (ad)i\big)$$. hopefully you agree?

wraith daggerBOT
#

haseeb

young shard
#

i see how that is yes

split ice
#

ok perf. the formula then does two things to simplify this:

  • changes i^2 to -1
  • factors out i from the second bracket
#

so we end up with $(ac - bd) + (bc + ad)i$, aka the general formula

wraith daggerBOT
#

haseeb

split ice
#

this is the subtle difference between the formula and the expansion. and to complicate things more, we had $d = -1$, so we should actually get $$(ac + b) + (bc - a)i$$ in that case!

wraith daggerBOT
#

haseeb

split ice
#

i think what you were doing is going along with the formula for your binomial expansion

#

which led to an extra pair of i*i

#

does that make sense?

young shard
#

yeah i think i see

#

i'll revise it later, closing this now, thanks

#

.close

cedar kilnBOT
#
Channel closed

Closed by @young shard

Use .reopen if this was a mistake.

split ice
#

gl ^^

cedar kilnBOT
#
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pseudo ingot
#

why is math so weird at patterns. im learning how to factor quadratic equations and i feel like every exception to the base concept of difference squares. just throws it out the window.

For example (x^2 - 15 = 0)

square root both and then do a positive and negative version of the equation to get both of the valid answers. Oh suddenly theres a number behind x^2?

(8x^2 - 15 = 0)

Throw out the square root step and find what 8 times -15 equals and then find the factor pairs to -120 to do this other stuff

what throws me off is the fact that theres no reason as to why i suddenly changed the whole way im solving the problem without there being a smooth connection or reason as to why other then (its basically a whole different problem so use a different method)

slender ginkgo
#

what does 'number behind x^2' mean

lone dune
#

i think hes talking about the coefficient

pseudo ingot
#

yeah

lone dune
#

you can still solve it the same way

#

$8x^2 = 15$

wraith daggerBOT
#

satvik

lone dune
#

$x^2 = \frac{15}{8}$

wraith daggerBOT
#

satvik

lone dune
#

and root both sides

pseudo ingot
#

huh whyd u do 8x^2 = 15? im factoring 8x^2 - 15 = 0

lone dune
#

you cant really factor that nicely

#

if you're solving a quadratic and you have only one term containing x which turns out to be the x^2 term, you can just isolate it and root both sides like I did here

pseudo ingot
#

the tutor video im watching had me multiply 8 and -15 and then find hte factor pairs and then square root 8x^2 into 4x and then write it like 8x + 12x - 10x -15 = 0

#

into then 4x(2x+3) -5(2x+3)=0

#

and then write (2x+3) (4x-5) = 0

#

.close

cedar kilnBOT
#
Channel closed

Closed by @pseudo ingot

Use .reopen if this was a mistake.

cedar kilnBOT
#
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paper bluff
#

If ( p(x) ) is a polynomial that satisfies
[
2p(x) + 2x^2 = p(x^2 - 2x + 4) + 8x + 5,
]
determine the units digit of ( p(2^{2022}) ).

wraith daggerBOT
#

isuckatmath

paper bluff
#

How can i prove that $deg(p(x)) = 2$

wraith daggerBOT
#

isuckatmath

reef glade
#

huh

#

vro lemme try once

paper bluff
#

k

flat mica
#

you know that's true somehow?

#

oh

#

I see why

#

i think

paper bluff
#

divide into 2 cases

#

if deg(P(x)) = 1 and if deg(P(x)) > 2

#

if deg(P(x)) = 1, take P(x) = ax + b

then 2(ax + b) + 2x^2 etc

tropic oxide
#

oh err

#

wait

#

if deg(p) = 2 doesn't the RHS become a quartic in x?

paper bluff
reef glade
#

deg ( p(x^2 -2x + 4) - 2p(x)) is 2

tropic oxide
#

p(x^2 - 2x + 4) is p evaluated at a quadratic

#

the degree of p(x^2-2x+4) is 2*deg(p)

reef glade
tropic oxide
#

$p(x) = a_n x^n + \text{(lower order terms)}$

wraith daggerBOT
tropic oxide
#

$p(x^2-2x+4) = a_n (x^2 - 2x + 4)^n + {}$ lower order terms of degree at most $2n-2$

wraith daggerBOT
reef glade
#

huh

paper bluff
#

sorry guys i suck a polynomials

tropic oxide
#

i mean maybe change your name to something that is not so self-deprecating while you're at it 💀

#

but also, again,

#

i'm not sure a polynomial even exists that satisfies this?

tropic oxide
#

self-hate is not good for the soul

flat mica
#

the contradiction is only if n>=2

flat mica
paper bluff
#

oops

paper bluff
flat mica
#

so let's take a look at lhs and rhs seperately

#

what's the degree of the LHS?

#

suppose p(x) has degree n

#

what's the degree of p(x)+2x^2?

#

let's go through cases

#

if deg(p)=2, what's the degree of p(x)+2x^2?

paper bluff
#

LHS is degree 2

#

RHS is degree 4?

flat mica
#

what if p=-2x^2?

paper bluff
#

oh yea

flat mica
#

let's just rule out p=0 because zero polynomial doesn't have a degree

#

it would give 2x^2=8x+5, which is false

#

p(x)-2x^2 has degree 2 or lower if deg(p)=2

#

agree?

paper bluff
#

yes

flat mica
#

great, let's go on the right hand side

paper bluff
#

and RHS has degree 4

flat mica
#

correct

#

so that's impossible

paper bluff
#

since like 8x + 5 can cancel out the x^4

flat mica
#

cannot you meann

paper bluff
flat mica
#

yes

#

two polynomials are equal if and only if all coefficients are equal

paper bluff
#

for n>= 2 it follows that LHS < RHS aswell

flat mica
#

correct

#

let's try n=0, 1

#

in other words, p(x)=Ax+B, where A and B might be 0

#

but not both zero we already tested

paper bluff
#

if n = 0 we can take P(x) = c for any constant c
if n = 1 we can take P(x) = ax + b for any a and b

flat mica
#

k let's try n=0 then see if that's a contradiction

#

you get

#

LHS: B+2x^2

paper bluff
#

and just bash, then we can get P(x) = bla bla bla, and we can get P(2^2022)

flat mica
#

RHS: B+8x+5

#

imposible

#

let's try n=1

paper bluff
#

ah it must be n = 1 then

flat mica
#

let's test it

#

LHS: degree 2

#

RHS, degree?

paper bluff
#

also degree 2

flat mica
#

so that's the only possibility

#

write p(x)=Ax+B, with A!=0

#

LHS = 2Ax+2B+2x^2

#

RHS = ?

paper bluff
#

ax^2 - 2ax + 4a + 8x + 5

#

so A = 2

flat mica
#

Almost but not quite

paper bluff
#

oops

#

lol i forgot b

flat mica
#

right

#

try again

#

A(x^2-2x+4)+B

#

so i'll just fix it for yiou, you were close

#

Ax^2-2Ax+4A+B+8x+5

#

is the RHS

#

2Ax+2B+2x^2

#

is the LHS

#

now you equate coefficients

#

A=2 like you said

#

wait

#

no not quite

#

wait yes

#

what am i saying

#

A=2

paper bluff
#

4A + B + 5 = 2B
B = 4A + 5
B = 13

#

so P(x) = 2x + 13

flat mica
#

yup

paper bluff
#

alr tysm

flat mica
#

np

paper bluff
#

.close

cedar kilnBOT
#
Channel closed

Closed by @paper bluff

Use .reopen if this was a mistake.

flat mica
#

i didnt solve the question on the paper though

paper bluff
#

nicee

cedar kilnBOT
#
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digital spoke
#

how do i do 9 the gpt isnt explaining it clearly

cedar kilnBOT
tropic oxide
#

anyway try to think about it visually: imagine rotating a line while keeping the point (-3,4) fixed, so that it kinda pivots around that point. and imagine rotating it clockwise until it starts going through Q4

#

what will its slope be then

digital spoke
#

huh

#

that makes no sense to me

#

i figured out this one

#

wait nvm its not gonna be on the test

#

.close

cedar kilnBOT
#
Channel closed

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cedar kilnBOT
#
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violet galleon
#

can anyone one help me in this question that came in my test? A is not the right option
people did it by value putting and stuff but how can we like get the answer by using standard location of roots or any other concept required for this?

wicked mantle
#

,rotate

wraith daggerBOT
cedar kilnBOT
#

@violet galleon Has your question been resolved?

cedar kilnBOT
#
Channel closed

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#
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exotic sundial
#

Would my sols be worthy of 3 marks

cedar kilnBOT
exotic sundial
#

These are the sols btw

cedar kilnBOT
#

@exotic sundial Has your question been resolved?

exotic sundial
#

<@&286206848099549185>

jagged tide
exotic sundial
jagged tide
# exotic sundial ^

Idk I don't have the energy to check thoroughly but if you've arrived at your answer without any weird assumptions then it's more probable to be correct

exotic sundial
#

ight thanks

jagged tide
#

Np

exotic sundial
#

.close (FYI part of my 'proof is wrong - the top part)

cedar kilnBOT
#
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cedar kilnBOT
#
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zealous haven
#

I need help with the basics of algebra

cedar kilnBOT
zealous haven
#

I'm struggling with my genmath because I lack the knowledge of the basics;-;

coral jewel
#

do you have a specific question in mind?

zealous haven
#

Hmmm wait

#

$$1/x-1 - 2/x+3 = 3/(x-1)(X+3$$

wraith daggerBOT
zealous haven
#

Breh

violet flume
zealous haven
#

Wait howd does this work;-;

violet flume
#

thoughts on first step?

zealous haven
#

Umm I find the LCD

#

Then solve it using it

#

But honestly Idk how

violet flume
#

theres a way to do these with less care

#

well, its basically lcm

violet flume
#

we want to collect all the unique denominators

zealous haven
violet flume
#

on the right hand side, yea, theres those two

#

are there any other unique ones?

#

or just more (x-1) and (x-3)

zealous haven
#

1?

violet flume
glass sphinx
violet flume
#

we want to just check every term, and if its divided by something, we make sure its in the list

zealous haven
violet flume
zealous haven
violet flume
#

on the left you have a term with bottom x-1

#

and another with x+3

zealous haven
#

Yep

violet flume
#

so no more

#

thats your lcm, the list

#

you now just multiply every term by the lcm

zealous haven
#

But how do you identify LCD's?

violet flume
glass sphinx
#

well make sure each side has same denominators then you can cancel them out

violet flume
#

lowest common denominator is lowest common multiple of the bottoms

violet flume
zealous haven
violet flume
#

you know lcm?

zealous haven
#

NAH

glass sphinx
#

$$\frac{1}{x-1} - \frac{2}{x-3} = \frac{3}{(x-1)\cdot(x-3)}$$

violet flume
#

also, lowest is really just a convenience

wraith daggerBOT
#

Ren🍓

violet flume
#

for our purposes, any common multiple will work

#

can you find a common multiple of 6 and 4?

zealous haven
zealous haven
violet flume
glass sphinx
#

$$\frac{(x-3)\cdot1 -2\cdot(x-1)}{(x-1)\cdot(x-3)}= \frac{3}{(x-1)\cdot(x-3)}$$

wraith daggerBOT
#

Ren🍓

glass sphinx
#

$$(x-3)\cdot1 -2\cdot(x-1) = 3$$

wraith daggerBOT
#

Ren🍓

zealous haven
violet flume
#

ill take off lol

#

gl ren

glass sphinx
#

basically I have simplified the fractions

violet flume
#

not leaving bc youre doing bad bread lol

#

this guy just barged in and i dont wanna cross talk

glass sphinx
#

kinda bored so

#

I will leave if you wanna help

violet flume
#

make as many enemies as possible speedrun

violet flume
zealous haven
crimson sedge
#

right?

violet flume
#

thats the first step

zealous haven
violet flume
#

theres only one

#

its your list

#

(x-1)(x+3) is the lcd

zealous haven
#

Soo that is just 1 lcd right?

violet flume
#

by design, there will be cancellations

zealous haven
#

Soo we add the lcd besides the upper numbers?

violet flume
#

we start with $\frac{1}{x-1} - \frac{2}{x-3} = \frac{3}{(x-1)(x-3)}$

wraith daggerBOT
#

jan Niku

violet flume
#

then, you multiply every term by the LCD

#

$\frac{ 1 \cdot (x-1)(x-3) }{ (x-1) } - \frac{2 \cdot (x-1)(x-3) }{ (x-3) } = \frac{3 \cdot (x-1)(x-3) }{ (x-1)(x-3) }$

wraith daggerBOT
#

jan Niku

$\frac{ 1 \cdot (x-1)(x-3) }{ (x-1) } - \frac{2 \cdot (x-1)(x-3) }{ (x-3) } = \frac{3 \cdot (x-1)(x-3) }{ (x-1)(x-3) }$
violet flume
violet flume
#

does that step make sense?

zealous haven
#

Yeh after we find the LCD we add them side by side

violet flume
#

yea but not add, we multiply every term by it

#

maybe you mean, we uhh, introduce it to each side

violet flume
#

idk anyways

violet flume
#

like, do you see the cancels?

wraith daggerBOT
#

jan Niku

zealous haven
#

Yep

#

Now from observing my teacher we know move to multiplying each of them

violet flume
#

well we should probably cancel first

#

im guessing

zealous haven
#

Yep

#

We cancel the x right?

violet flume
#

well, like in the first term, you have x-1 in the bottom, and in the top

#

so we can cancel

zealous haven
#

Can you illustrate?

violet flume
#

$1 \cdot (x-3) - \frac{2 \cdot (x-1)(x-3) }{ (x-3) } = \frac{3 \cdot (x-1)(x-3) }{ (x-1)(x-3) }$

wraith daggerBOT
#

jan Niku

violet flume
#

the x-1 goes away in the top and the bottom

#

this is just like if we had $\frac{2x}{2}$, it would become just $x$, because the 2's would cancel

wraith daggerBOT
#

jan Niku

zealous haven
#

Soo first we cancel out the bottom then next is the 2nd?

violet flume
#

you mean the next term

#

?

#

by design each term will have something that cancels out

zealous haven
#

Soo cancel out them one by one?

violet flume
#

yea, each term will have something that cancels

zealous haven
#

Man I wished there were arrows to point out the steps

violet flume
#

hmm idk how make arrows

#

its just this

zealous haven
violet flume
#
  1. find the lcd
  2. multiply by the lcd
  3. do the cancellations
  4. solve the new problem
zealous haven
#

Can you use a website sketchboard?

silk gust
wraith daggerBOT
#

Frances

violet flume
#

how about this

#

heres the cancellations with colors from ms paint lol

zealous haven
#

Yes!!

#

Like this I mean

zealous haven
violet flume
#

ah, annoying at some point we flipped x+3 for x-3

#

but its fine

#

brb

zealous haven
#

Ok contunue

zealous haven
violet flume
#

have you finished cancelling everything

zealous haven
#

wait

violet flume
#

yea

#

not to drop anything too crazy on you, we accidentally messed up a sign because of that ren guy

#

you did everything right but it should be

#

$1 \cdot (x+3) - 2(x-1) = 3$

wraith daggerBOT
#

jan Niku

violet flume
#

how do you feel baout solving the problem from here?

zealous haven
#

Umm what do I do next exactly?

violet flume
#

solve for x

zealous haven
#

like 1 times x?

#

then thats cancel then 1 x 3 thats =3?

violet flume
#

oh, distribute

#

yea thats probably the next step

#

so 1 (x+3) is just x+3

zealous haven
#

Yep cuz 1 is basically x at thi point, right?

remote nacelle
#

same property as saying 2(1+3)= 2x1 + 2x3

remote nacelle
violet flume
fast osprey
zealous haven
violet flume
zealous haven
#

Yes

glass sphinx
#

omg are you still helping

violet flume
#

2(x-1) = 2x - 2

#

by the distribute property

zealous haven
#

I do it like this?

violet flume
#

yea, exactly

zealous haven
#

-2x

violet flume
#

well it also hits the -1

#

$-2(x-1) = -2x + 2$

wraith daggerBOT
#

jan Niku

zealous haven
#

Where did the positive 2 came from?

fervent badger
wraith daggerBOT
#

Ivan_Holy

zealous haven
#

Dang the signs also counts?

fervent badger
#

Yeah

zealous haven
#

Soo that becomes -4x?

violet flume
#

inside the ( ) you have an x, and a number

#

so we get a term with an x

#

and then a term thats just a number

#

$-2(x-1) = -2x+2$

zealous haven
#

I knew something didn't quite add up with +2

#

Cuz how does$$- x - = 2?$$

wraith daggerBOT
remote nacelle
#

-2x+2 no?

wraith daggerBOT
#

jan Niku

fervent badger
violet flume
#

sorry im packing blobsweat running around a hotel room

#

soon i will have to power down my computer bearlain

#

but @zealous haven youre very close

#

it seems like we have $x-3-2x+2=3$

wraith daggerBOT
#

jan Niku

violet flume
#

final stretch catthink

zealous haven
zealous haven
wraith daggerBOT
violet flume
zealous haven
#

Or am I wrong;-;

fervent badger
wraith daggerBOT
#

Ivan_Holy

violet flume
#

@fervent badger can you take over blobsweat

fervent badger
remote nacelle
#

i can do it

zealous haven
remote nacelle
#

that’s what we have until now from the beginning

#

the next step is to combine the x’s and the numbers together in the left hand side of the last equation

remote nacelle
zealous haven
#

Ain't x-2x=-2x?

remote nacelle
remote nacelle
zealous haven
#

Dang never seen =-x before;-;

remote nacelle
#

it’s -1 times x

fervent badger
#

Yeah, but normally in math, you dont write that 1, you just write -x.

zealous haven
#

Ohhh

#

soo pretty much its just 1-2=1 which is X

remote nacelle
fervent badger
remote nacelle
#

x is a number, we just don’t know what it is yet, so it obeys the same rules as the other numbers

remote nacelle
zealous haven
#

Yep

remote nacelle
zealous haven
#

Soo in total we have 5x?

remote nacelle
#

no it’s -x+5

fervent badger
#

When its plus, you just "glue" that -x to five.

zealous haven
#

soo 5 ib total?

remote nacelle
zealous haven
remote nacelle
#

the simplify part we did earlier with x-2x= -1x = -x

#

then since x+3-2x+2=-x+5, i could substitute it as the left hand side

remote nacelle
# zealous haven How-

This pre-algebra video tutorial provides an introduction / basic overview into common topics taught in that course. It covers mathematical concepts such as adding and subtracting integers, order of operations, solving equations, and simplifying fractions. These review lessons are useful for any student taking pre-algebra.

Here is a list of to...

▶ Play video
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you have to be able to simplify expressions with x’s in them before to solve them

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it’s in pre-algebra

zealous haven
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Wait the value of x is 2 right?

remote nacelle
# remote nacelle

then in algebra you will use this to simplify equations like i did here

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yeah once you have -x+5=3

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you can see it or subtract 5 from both side

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to get -x=-2

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then multiply -1 both sides to get

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x=2

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i think i will also give you this table summarizing some things you can do with numbers including x to simplify expressions

zealous haven
fervent badger
zealous haven
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Ahh I seemed to forget that a variable's value is always 2

remote nacelle
zealous haven
fervent badger
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And thats the x.

remote nacelle
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for any other x you will plug in, you have that 1/(x-1) - 2/(x+3) won’t equal 3

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and we did that by applying rules that simplify the equation you started with while preserving the x where it’s true

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to the point where we ended up with -x+5=3 and you were able to just see that only x=2 works

zealous haven
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Soo the final answe is -2?

remote nacelle
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no it’s 2

fervent badger
#

$-2*(-1) = 2, because (-)*(-) = +$

zealous haven
wraith daggerBOT
#

Ivan_Holy

fervent badger
remote nacelle
#

remember -x = -1 times x

zealous haven
remote nacelle
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it’s simply a notation for -1 time x which is the same for numbers like you write -6 or -32

zealous haven
remote nacelle
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no you have to MULTIPLY both sides by -1

remote nacelle
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or you can look at the equation and see that the only solution is x=2

fervent badger
zealous haven
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Soo just keep stacking up till you get the final answer? (From what I understand)

remote nacelle
fervent badger
remote nacelle
#

annotated

zealous haven
zealous haven
remote nacelle
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from the 5-5

fervent badger
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Did you learn how to solve basic equations?

remote nacelle
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i was more explicit showing you the move of subtracting 5 from both sides

rapid mauve
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(it's called equation balancing, by the way)

remote nacelle
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things like 1 (x+3) -2(x-1) from before

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being simplified to -x+5

zealous haven
fervent badger
zealous haven
fervent badger
zealous haven
fervent badger
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The more you exercise, the more you will understand.

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The key point is not just to solve this, but to understand how you did it.

zealous haven
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Cuz every equation is the same steps.

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Which is the same with algebra from what I have observed y'all teaching me

frail citrus
remote nacelle
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imo instead of memorizing steps and patterns to solve each kind of question, it’s more efficient to understand how the game works, what are the move you can make whatever the equation may be

zealous haven
fervent badger
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When you are ready, you can close this channel.

zealous haven
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Ok!

remote nacelle
#

that might be intimidating but if you are very explicit

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here are the main moves that were played for this problem

cedar kilnBOT
#

@zealous haven Has your question been resolved?

#
Channel closed

Closed by @zealous haven

Use .reopen if this was a mistake.

zealous haven
cedar kilnBOT
#
Available help channel!

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supple wigeon
#

here is a problem i'm thinking of, but unsure the field. topology? geometry?

question: how to know from the output string that the resulting shape is real, truchet, and which parts are concave and convex?

supple wigeon
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here is the newer version not transparent

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it is a valid shape if the shape is closed, and the path doesn't intersect itself.
whether it is truchet is another problem. detecting convexity is another...

cedar kilnBOT
#

@supple wigeon Has your question been resolved?

tropic oxide
#

what's a truchet shape

dire geode
#

In information visualization and graphic design, Truchet tiles are square tiles decorated with patterns that are not rotationally symmetric. When placed in a square tiling of the plane, they can form varied patterns, and the orientation of each tile can be used to visualize information associated with the tile's position within the tiling.
Truch...

cedar kilnBOT
#

@supple wigeon Has your question been resolved?

supple wigeon
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this is more what im visualizing

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but maybe truchet isn't the right word...

random swift
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I think "truchet" is talking about the tiles themselves, not the tiling?

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What do you mean by "real" also?

supple wigeon
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i think the term 'grid based rounded shapes' rather than truchet might be more accurate

cedar kilnBOT
#

@supple wigeon Has your question been resolved?

cedar kilnBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

cedar kilnBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

craggy haven
cedar kilnBOT
craggy haven
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im slumped

silk gust
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!status

cedar kilnBOT
#
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
craggy haven
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i don’t know where to go from here

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the answer i got was wrong

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it should be 4

silk gust
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im not really sure i see what the chart is for

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i have another way but i want to hear your thought process first

craggy haven
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we learnt it like that

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idk

silk gust
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ok uh

craggy haven
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heh

silk gust
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dyk why there are specific values of 5 and 3 on the rightmost column?

craggy haven
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no that’s what i got after mathing