#help-0

1 messages · Page 736 of 1

willow wadi
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For this question do u get
**
Resolve a force of 200N in the direction S 22 degree E into its regular componets
do u get **
East = 200 cos (68) and South = 200 sin (68)

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<@&286206848099549185>

wary stream
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If that force is Southeast, then that angle you used is technically wrong

willow wadi
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oh if not

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then its right

wary stream
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You used the proper trig functions for each direction

bitter sage
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hey anyone know how to solve this question?

tight locust
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what is B?

noble sinew
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Only 1 value of B possible such that LHS limit equal to RHS limit

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But not rly required to even calc RHS limit

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Just calc LHS limit and set A equal to that

bitter sage
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wdym calc lhs limit?

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can you show what u mean?

noble sinew
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Calculate limit as x approaches 1 from the left

bitter sage
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so i use the x^2 + 2x - 3/x - 1 and lim x-> 1

noble sinew
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Yes

bitter sage
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and that gives me a?

silk veldt
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Is this the correct process for the algebraic question?

bitter sage
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so a = 4?

noble sinew
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Si

bitter sage
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Ok

noble sinew
bitter sage
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The question seems like it would be a lot harder

silk veldt
noble sinew
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Yep

silk veldt
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Thanks for the help

ashen plaza
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Oooooooo

spice imp
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So me and my mate were talking about how fast you would need to move to stay the same spot under the moon at all times. I said 1670km/h, since its just moving the circumference of the earth in 24hrs. He isnt satisfied, and we want to know if the moons orbit would factor into this in any meaningful way

ionic jewel
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it's about the right answer, but for the wrong reason

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it actually takes 27 days for the moon to orbit the earth

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you just get to use the earths rotation to help

spice imp
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So could i make it more accurate? Nvm dont tell me, ill try figure it out and come back

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So, if the earth didnt rotate to start, you would need to go 24.7km/h to stay under the moon. The earth rotating seems the complicated bit now, considering youd add or subtract(not sure) the relative velocity of the rotation at whatever point on earth youre at, right?

normal hazel
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Lmao are these kindergarten questions?

ionic jewel
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I'm pretty sure your first answer was mostly accurate, but i was just pointing out how it could be more complex if you wanted to look more into it

glass lichen
ionic jewel
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of courses, the moon's orbit isn't a perfect circle either, so there's plenty of other things that could be a problem

spice imp
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Yeah, unfortunately i dont have the know how or patience to factor the moons orbit or earths rotation into it

ionic jewel
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your approximation is about right

modern wren
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IS anyone Familiar with Ramsey Theory?

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I found a Transform Function for base 3

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It generalizes but ill be doing that tonight

modern wren
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?

alpine sable
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<@&268886789983436800>

sly mantle
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ty

wary stream
# sly mantle ty

Just to confirm, people can't promote other servers? I was gonna ping mods but I had to look at the rules to double check and didn't see anything so I was hesitant

heavy otter
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The rule is against unsolicited advertisement

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there's no problem with linking a server if it's relevant to the conversation and/or the other person asked for it

wary stream
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Ah, I see, thanks for clearing that up

wary stream
elfin talon
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Ok

sly mantle
elfin talon
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I disappoint my self sometimes lol

alpine sable
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If you can't swim with the sharks you aren't a titan.

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one thing that I can't wrap my head around is that we always say that subtraction does not share the same properties that addition does (i.e commutative and associative) yet subtraction can be written as addition? e.g 4-5 = 4+(-5), a+b-c= a+(-c)+b

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hey guys what's the difference between sin and |sin|? what does | mean?

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I believe it is the absolute value? https://en.wikipedia.org/wiki/Absolute_value

In mathematics, the absolute value or modulus of a real number x, denoted |x|, is the non-negative value of x without regard to its sign. Namely, |x| = x if x is positive, and |x| = −x if x is negative (in which case −x is positive), and |0| = 0. For example, the absolute value of 3 is 3, and the absolute value of −3 is also 3. The absolute valu...

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thanks

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np

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is that clojure?

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your avatar

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or some other lisp dialect

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that's the DeepMind logo

unkempt tulip
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aaaaaaaa

honest hawk
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Do you mind if i get some help on this one?

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The formula in question is this:

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But, I guessed the right answer due to the difference of 80 and 30 being 50.
How would one mathematically apply this to show proof though?

astral dagger
honest hawk
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ah

astral dagger
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also, this logarithm is base 10

honest hawk
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For reference, it gives me the explanation, but it isnt the best:

ocean sealBOT
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SubGui

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SubGui

honest hawk
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(thanks for the assistance, by the way. Im a bit all over the place today.)

astral dagger
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such that you just need to put 80 and 30 on the left side of the equation and solve for the maximum and minimum intensities

ocean sealBOT
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SubGui

honest hawk
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ah. that makes sense. Ive always been murky with reverse engineering logarithms

north hemlock
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Hello! I am trying to write an analysis of this histrogram and boxplot but I don't know what more there is to discuss about these

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I need 2 slides but I only have one so far with what seems to be all the relevant information

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is there anything I am missing or things I can talk more about?

north hemlock
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<@&286206848099549185>

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👀

queen nova
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what is it called when a line on the graph is horizontal and straight

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<@&286206848099549185>

plucky radish
queen nova
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I'm trying to write a function for the following problem: Jeania’s parents have given her a interest-free loan of $100 to buy a new pair of running shoes. She plans to pay back the loan with monthly payments of $20 each.

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I put P = b(p) = -20m + 100 is that right?

topaz scaffold
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It should be b(m)

queen nova
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the question said to set it to b(p)

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Write a function rule for the balance of the function B(p), where p represents the number of payments Jeania has made.

topaz scaffold
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Then you gotta use p instead of m

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Since it's a function of p

queen nova
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oh ok

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so -20p + 100?

topaz scaffold
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Yea

lucid beacon
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Could anyone help point out the errors in my solution? Also I'm not sure if this is the correct channel

queen nova
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ok got it tysm

lucid beacon
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Question: 2log(x+3) = log(ax) has only one solution. Find the value of a

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I assume that's it is an integer solution but it isn't specified

ionic jewel
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slap the 2 into the log using the relevent log rule, then remove the logs

topaz scaffold
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Bring the 2 inside the log

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Oh

lucid beacon
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I managed to get a = (x+3)^2/x

ionic jewel
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,w (x+3)^2 = ax, a > 0

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:thonk:

topaz scaffold
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Then solve the quadratic

glass lichen
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why the hell did I think it was a cubic sully

topaz scaffold
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So a = 12

lucid beacon
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Yeah I thought a trivial solution was a = 0, lol

glass lichen
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no

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cause then you'd have log(0)

lucid beacon
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Yeah

glass lichen
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so a clearly cant be 0

ionic jewel
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i mean there's multiple integer solution pairs for (x,a)

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there's no global a that works for all x

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so idk what they want

glass lichen
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they want the quadratic you get to only have 1 solution

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so ||discriminant of 0||

lucid beacon
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Okay thanks guys

north hemlock
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Hello! I am trying to write an analysis of this histrogram and boxplot but I don't know what more there is to discuss about these. I need 2 slides but I only have one so far with what seems to be all the relevant information. is there anything I am missing or things I can talk more about?

snow nest
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oh my god

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is that an AMC question

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holy shit that gave me chills for some reason

frosty jungle
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Guys what is 1 + 1 ?

north hemlock
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pain

topaz scaffold
wanton orbit
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hello friends. i'm trying to wrap my head around this one, but how do i calculate a percentage increase to another percentage? (x% rises / falls to y% , the difference measured in a percentage)

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i hope it's not too much of a dumb question angerysad

alpine sable
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@wanton orbit do you mean for example: x is increased by y% to z%, where you know y and z but not x?

wanton orbit
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i think not,

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lemme try rephrase it

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x% of a random number rises to y%, and i need the difference in a percentage?

alpine sable
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i'm not really sure what you mean, sorry

wanton orbit
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it's ok man

queen nova
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what is the constant term in this equation: -8x2 + 54x + 140

ionic jewel
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140

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it's the one without the variable

queen nova
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ah ok

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ty

topaz scaffold
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y%/x% -1 should be the percent increase

wanton orbit
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oki doki

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minus one?

topaz scaffold
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Yea

wanton orbit
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okay

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thank u

north hemlock
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pog

wanton orbit
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hold on, man. i don't know if this is the right one. the calculus isn't adding up.

topaz scaffold
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Oof

north hemlock
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calculus on percentages kekw

wanton orbit
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a 15.4% of the population claimed to be evangelical, in ten years, it rose to 22.2%, this news article claims it has risen in 61%, i'm trying to get the formula of this thing so i can continue with this assignment

north hemlock
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imagine if the news is fake xd

wanton orbit
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it's probably not, it's has data from the national demographics center

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which have (presumably) better mathematicians than me

north hemlock
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well 15.4% to 22.2% is a 44.2% increase

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44.15584415584415

wanton orbit
north hemlock
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,w ((22.2 - 15.4)*100)/15.4

north hemlock
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yep

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or u can do ,w ((22.2)/(15.4))-1

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,w ((22.2)/(15.4))-1

north hemlock
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which is the same but not as a percent (yet)

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to get that to be a percent, just *100

ionic jewel
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,calc 1.61*15.4

ocean sealBOT
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Result:

24.794
ionic jewel
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definitely not 22.2

north hemlock
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true

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"news article claims it has risen in 61%," #FakeNews ggwp

wanton orbit
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,w ((22.2)/(9)-1

wanton orbit
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seems legit

north hemlock
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hm

wanton orbit
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angerysad gosh darn it

north hemlock
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what're you trying to do exactly

wanton orbit
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calculate percentage growth

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from 22.2% to 31%

ionic jewel
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we already did that didn't we

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,w .31/.222-1

wanton orbit
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that makes it a

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39% increase?

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from 22.2% to 31%?

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is that it? flonshed

unborn dome
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can someone help me with this?

alpine sable
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Hey guys need some help checking this... I think I did it right? But I got slight different numbers for the solutions. I know the end result is the same because there are no solutions but... not sure if I messed up somewhere ?

alpine sable
# unborn dome can someone help me with this?

I could be very very wrong, but from what I remember you just pick some random number ( in between the constraint) as your "w" and then solve for all those possible solutions... which If I remember correctly means you just say + 1/2pi... or whatever to resemble all solutions in that range

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So basically you need to come up with a formula that works for all solutions in that range

undone dock
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i think its just a quadratic in terms of cos(w)no?

alpine sable
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Yeah its a quadratic

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But it wants every solution for every possible angle between 0 and 2pi

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I remember it was pretty easy I just forgot exactly how you do the notation

alpine sable
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Im pretty sure this is the exact same problem with just a quadratic

unborn dome
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hm

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ill have to watch that

alpine sable
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Yw lol

unborn dome
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ty

alpine sable
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I remember alot of geometry.. since I took it THREE FREAKING TIMES. If you need the DL lemme know

azure forge
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hello can someone help me with this word problem arithmetic sequence?

ionic jewel
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for which one

azure forge
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both hopefully

ionic jewel
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well lets do the first one

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so lets say it has 1 unit of air it in it start

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then after 1 second, it loses 1/20 of it

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so how much air does it have now? @azure forge

azure forge
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0.95?

tight locust
glass lichen
tight locust
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have you? i've clearly helped him more than you have

jade kestrel
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Been dealing with modular arithmetic a lot lately and I wanted to find an easy algorithm for computing exponents.

So I figure out that
I could simply reduce the output after each operation using mod. Quite obvious solution.
So then
2^5 mod 5

2*2 = 4
4*2 = 8 = 3
3*2 = 6 = 1
1*2 = 2

But what if I do
2^5 mod 4

2*2 = 4 = 0
0*2 = 0
0*2 = 0

This is problematic.

glass lichen
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You didnt help them at all but ok

ionic jewel
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it would be A(.95)^6 for an original amount A

azure forge
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what does ^ mean?

tight locust
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it asks for the percentage

glass lichen
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exponent

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$a^b$

ocean sealBOT
ionic jewel
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exponent

azure forge
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oh okay thanks

tight locust
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A doesn't matter

ionic jewel
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i mean its still a different number

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,w 1 - 1/20^6 = 1(.95)^6

tight locust
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and it asks for the amount remaining. hence the subtraction from 1

tight locust
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learn to read

glass lichen
tight locust
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i'm not

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i'm exercising great restraint

ionic jewel
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also ur still not right

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ur telling me that despite the fact it loses 1/20 of the air just on the first second, it still has 99.999999% left?

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if you absolutely need the disparaging comments at least be correct

alpine sable
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Can I get help on this problem on which I am stuck at from yesterday night?

glass lichen
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Also given b was about exponential growth and decay, and they're both from the same sheet of questions, you can safely guess that a is also about exponential growth and decay

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aside from the fact the wording implies 1/20 of the air in the containter per second

unborn dome
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uh

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i know one of the answers is 0.666 so i rounded that to 0.67 and got partial creddit

tight locust
ionic jewel
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fair enough, in that case its the same thing 👍

unborn dome
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but its accepting 0.67

lusty plaza
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weird

unborn dome
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not so sure how 5.61 is wrong tho

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i converted 0.67 into degrees

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subtracted that by 360

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then turned that answer into radians again to get 5.61

azure forge
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idk who to follow 😳

alpine sable
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(1-1/20)^6

glass lichen
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$1-\sin^2(w)-\sin(w)=0$

ocean sealBOT
alpine sable
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Becomes a quadratic 😳

unborn dome
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yea

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one of the solutions gets crossed out because it goes below the limit in the inequality

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the other one that doesn't get crossed out is

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sqrt5 - 1 / 2

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arcsin(sqrt5 -1 / 2) = 0.666 or 0.67

glass lichen
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,w solve x^2+x-1=0

tight locust
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not quite golden

unborn dome
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cant you re-order it

glass lichen
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yeah so you're solving $\sin(w)=\frac{\sqrt{5}-1}{2}$

ocean sealBOT
unborn dome
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yep

tight locust
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plus or minus

glass lichen
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already been accounted for...

unborn dome
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the minus gives u a negative answer which is below the limit

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so yu take postiive

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arcsin of that

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thats 0.67

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after that i convert this into degrees

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so

glass lichen
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does it just want the exact answers...?

unborn dome
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yea.

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its taking in the 0.67

glass lichen
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yeah cause that's an approximate answer

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im asking does it want the exact answers

unborn dome
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tried it with pi o na previous question and it made it incorrect so im not sure

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for now i'd assume decimal is the safe route

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okay hear me out @glass lichen , 0.67 into degrees thats 38.39

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360 - 38.39 thats 321.61

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i then converted 321.61 back into radians

glass lichen
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that's wrong

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that's why

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it's sine not cosine

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sine is negative in quad 4

unborn dome
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oooooooooooooooooooooooooooooooooooooooh

glass lichen
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you want pi-(reference angle)

unborn dome
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aaaahhhhh that hurts

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so pi - 38.39 ?

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or pi - 321.61

glass lichen
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no...

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$\pi -\arcsin(\frac{\sqrt{5}-1}{2})$

ocean sealBOT
unborn dome
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wow

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I feel like a complete jackass 😦

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for overseeing that sin thing aaaah

void hearth
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I tried finding some way to express RM in other vectors, and came up with RM - RS = SM <=> RM - b = SM

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then I tried finding some way to express SM in other vectors, and came up with SM + MQ = SQ <=> SM = SQ - a

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sub the 2nd equation into the first, I get

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RM - b = SQ - a

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I cant figure out what to do next

unborn dome
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can someone help me out with this question btw

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this is cancerous

void hearth
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use double angle formulae

strong furnace
# void hearth

if you look at the diagram you have kind of only used the quadrilateral SQRM for the equations you have right now , doing similar things with the other quadrilateral would help you get there

unborn dome
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im assuming i do something like this @void hearth

void hearth
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sin2x = 2sinxcosx, you can use pythagorean to solve for cosx

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x is the angle, not the side

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but youre on the right track

unborn dome
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yea

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so

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x^2+7^2 = 8^2 @void hearth

void hearth
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yeah

unborn dome
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x = sqrt 15

void hearth
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cosx = sqrt(15)/8

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and you have double angle formula so

unborn dome
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wait what...

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where di d u bring cos from

alpine sable
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A plank of wood 24m long has an 8m long piece cut off it. Express, in simplest form the ratio of the length remaining to the length cut off?

void hearth
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sin(2x) = 2sin(x)cos(x)

main zephyr
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is this correct?

charred flint
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,rotate cw

ocean sealBOT
charred flint
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nah, you found BA

main zephyr
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oh

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so i need to sub 5

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aight thanks

charred flint
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yup

unborn dome
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wait

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for sin wouldnt that just be for sin thats 2/1 * 7/8 * 7/8? @void hearth

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cuz they're already giving me sin

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oh shoot that cos(x)

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adjacent over hypotneuse

void hearth
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yeah you have to find cos(x), ratio of adjacent and hypotenuse and plug that in

unborn dome
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i mean

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yea

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whoops

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sqrt 15 / 8

void hearth
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so

unborn dome
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2/1 * 7/8 * sqrt 15/8

void hearth
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sin(2x) = 2sin(x)cos(x) = 2(7/8)(sqrt(15)/8)

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yeah

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and you simplify

unborn dome
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thats 7sqrt15/32

void hearth
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yeah

unborn dome
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LETS GOOOOO

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now its tangent time boi

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uh

void hearth
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tan(2x) = sin(2x)/cos(2x) so you can figure something out

unborn dome
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thats 2tan a

void hearth
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by dividing the first 2 results you get

unborn dome
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wait really

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thats it?

void hearth
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yeah

unborn dome
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wow... im really...

void hearth
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comes from tan(x) = sin(x)/cos(x), same idea

unborn dome
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its -7sqrt15 /17

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pog

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got it right

void hearth
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yeah

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just remember whenever you see 2x, x/2, or something involving 2 double angle formula helps

unborn dome
#

got it

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thank you chief

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and now I'm confused again @void hearth pepehands

void hearth
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cos^2(x) - sin^2(x) = cos(2x)

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you see the first terms, they have the same number right

unborn dome
#

wait

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isnt that just 74 degrees

void hearth
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yeah

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youve got it

unborn dome
#

wow....

void hearth
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just multiply or divide by 2

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mindblown

unborn dome
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i feel so...

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well i got it right

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thanks man

tame horizon
#

Help please

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I don't understand the question

unborn dome
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can someone help me on this please

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for sin this is what I got

rigid smelt
#

the half-angle formula for sine is $\sin(x/2)=\pm \sqrt{\frac{1-\cos(x)}{2}}$

ocean sealBOT
rigid smelt
#

you messed up your sign

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oh wait nvm cos(x) is negative

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and cos(x) is not -sqrt(35)/4

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you probably miscalculated somewhere

unborn dome
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oh shoot

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its

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sqrt 35/6

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wtf.

rigid smelt
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-sqrt(35)/6 but yeah

unborn dome
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yes

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wait no

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wouldnt it become a positive

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because 2 negatives

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make a positive sign

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if its 1 - (-sqrt35/6 / 2

rigid smelt
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yeah i know

rigid smelt
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i was implying that cos(x)=- sqrt(35)/6 not the the number in the square root

unborn dome
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AH i got it

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LETS GOO

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and for tan i can just divide the two right @rigid smelt White

rigid smelt
#

yeah

rigid smelt
#

and im not walter white thonkzoom

unborn dome
#

you are now Waler White from now on

rigid smelt
#

...

unborn dome
#

say my namee...

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anyways thanks for the help

sudden tulip
#

How do I solve iii

gray isle
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Consider that a rhombus is a special type of parallelogram

slate heron
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$\overline{PQ}=\overline{QR}=\overline{RS}=\overline{SP}$

ocean sealBOT
sudden tulip
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Hmm

slate heron
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all sides of the rhombus are equal

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just prove that

sudden tulip
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Ok thanka

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9 how do I do

rigid smelt
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when two graphs of two functions meet, they equate each other

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but before doing that, i'd suggest finding y

sudden tulip
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Ok how do I find y ?

rigid smelt
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algebra?

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if i gave you xy + 2 = x, can you find y?

sudden tulip
#

Yep

frosty notch
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is pi = 4

rigid smelt
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idk man, i wish there is some kind of tool for us to type in our simple and probably very frequently-asked question so we can get the answer

slate heron
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π=C/d

topaz scaffold
rigid smelt
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yeah but who am i to create such a thing

slate heron
#

What

topaz scaffold
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Obviously the best is $π = 4 \sum_{n=0}^{\infty} \frac{(-1)^n}{2n+1}$

ocean sealBOT
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RipeOrange

carmine lion
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uh what

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anyways,

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how do i know if this is unique

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$f(x)=-x[(x+4)(x-3)]^2$

ocean sealBOT
astral dagger
carmine lion
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the only way for the function to be not unique

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would be if i didn't know its y-int

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so what i gave is correct right?

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oh nvm

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the function can be compressed

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or expanded

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nvm

astral dagger
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I think that as you're talking about polynomials, compressing or expanding would mean multiplying by some factor in front of the equation

carmine lion
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yes

astral dagger
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so it'd still be the same function?

carmine lion
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so it would be unique only if i knew the y-coordinate of at least 1 turning point

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here the turning points have no listed value

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so its not unique

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¯_(ツ)_/¯

astral dagger
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being a poly'al, its derivatives are 0 at some point, so maybe there's such behavior on it's critical points and concavity but..

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maybe it doesn't answer your question

carmine lion
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if you know where dP(x)/dx=0

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then its unique

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that should be enough reasoning

astral dagger
#

it is a 5th degree polynomial

carmine lion
#

yes

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look

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if i change the value of a

astral dagger
#

doesn't look the same

carmine lion
#

the turning point y-coordinates change

#

so that means the function ain't unique

#

because it doesn't give enough information

astral dagger
#

indeed

carmine lion
#

alr

#

👍

#

just wanted to clarify

#

ty

astral dagger
#

If I was of some help

#

well, am going sleep, have a good night KEK

topaz scaffold
#

Gn

deft stirrup
#

hey guys i have a question about courses, im going to be a junior next year and have the choice between pre-calc and stats, what is the difference and which do you recommend

ionic jewel
#

difference: they are completely different classes with literally no overlap

advice: depends what you want to do, but if you have literally any interest in a STEM field of any kind you will need both eventually

#

most people do the pre-calc into calculus route first though

deft stirrup
#

what if im interested in finance

#

ive heard stats is more useful for that

ionic jewel
#

you will want both still

topaz scaffold
#

I would say do precalc

ionic jewel
#

if you plan on doing a college degree you can look at the finance graduation requirements, iirc at my university you need up to calc 2 and one stat class

deft stirrup
#

ah ok

ionic jewel
#

i would recommend pre-calc as well

topaz scaffold
#

Helps build the fundamentals

deft stirrup
#

awesome this was really helpful thanks

topaz scaffold
#

What's up with the exclamation mark?

main escarp
#

hey I need help,
With this question am i the stupid one or is my teacher

here when she take -2 away from -12 isnt that -10 not -14?
(-12)-(-2) = 10?

#

^ the question

#

its during the first butterfly step

#

ping me pls

#

(might be confusing due to annotations but ignoring x3

slate heron
#

Taking away a negative number adds it. imagine if someone takes away a parking ticket from you - you dont have to pay the parking ticket so you sort of "gain" money

#

wait one sec

#

ive read your thing wrong

main escarp
#

?

slate heron
#

why is she wrong?

main escarp
#

idk

#

im confused

slate heron
#

shes subtracting 2 from -12

main escarp
#

yes

#

waot

slate heron
#

-12-2

main escarp
#

i did wrong

slate heron
#

not -12-(-2)

main escarp
#

yeah

#

i see now

#

i read inccorrectly

#

thanks for help

#

lol

manic glade
#

this is wrong right? the 1/1 shouldnt be there(?)

placid zinc
#

That's sus. Is there a context?

manic glade
#

its part of a longer proof but its self contained

#

thats the only other part relevant to and preceding it, but its the same issue

#

(0,1) doesnt include 1 right?

placid zinc
#

True

#

Yeah you're right, so the subset symbol is a lie

#

Likely just a printing mistake, and it is hard to gauge how important the mistake is

ionic jewel
#

the first screenshot is correct though, isn't it?

#

wait $\frac11 \subset \bQ$

ocean sealBOT
ionic jewel
#

so it's fine i can't read, it's not fine

manic glade
#

yeah i guess the cardinal is the same anyway

#

should have screenshoted the subset part

#

but still, shouldnt be there since they reach that conclusion by starting with the subset claim

slate heron
placid zinc
#

Does making it [0,1] break everything?

manic glade
#

the question is specifically about (0,1)

#

just starting with 1/2 should be fine though i reckon

ionic jewel
manic glade
#

btw anyone know a good math editor addon for googledocs?

#

currently using hypatia and its pretty terrible

#

everything is a struggle and it bugs out a lot

#

also no colors

slate heron
#

use latex lmao

manic glade
#

well it is latex but you need an addon to add it to docs

#

afaik

#

theres no built in options it adds math as images

slate heron
#

must you use docs

ionic jewel
#

hes saying using latex instead of google docs

#

like literally worst case you can use latex for your equations in a different program then screenshot and add to google docs lmao

slate heron
#

lol. go on #bots, render latex with the bot, copy image, paste

manic glade
#

but i can already do that within the doc using any of the addons, thats literally what they are for

#

its just latex editors

halcyon pulsar
#

What would be Exterior angle of pentagon?

manic glade
#

theres just a bunch of them was wondering if anyone has experience with a nice one

halcyon pulsar
#

?

#

Or 72°

manic glade
#

72

#

assuming its a regular one, it can vary otherwise

ionic jewel
manic glade
#

rip

halcyon pulsar
manic glade
#

i googled the question tbh

halcyon pulsar
#

Hmm

#

Shouldnt interior angle be 72• insteat of exterior angle being 72°

manic glade
#

360 / sides

opal pier
#

What is the mathematical chance a portion land in my yard

woeful pulsar
opal pier
#

3 pigeons in my neighborhood

#

~ 100 other yards

placid zinc
#

Depends on how much bird seed you own

woeful pulsar
opal pier
#

No

woeful pulsar
placid zinc
#

In order to predict a pigeon, we gotta think like a pigeon

alpine sable
#

is the ans tan-1(x) ?

pure hill
#

try substituting x with tan^2t and you will get your answer

tribal geyser
#

Hey guys can someone help me with 9a)? I don’t get where L came from in the answer

#

Like I worked it out but instead of L I got dB

ionic jewel
#

(or L = dB)

tribal geyser
#

Oh because I literally don’t see L anywhere haha

#

but thank you for the confirmation

#

@ionic jewel

alpine sable
#

can you help

pure hill
alpine sable
#

i tried, but dont kno

#

i think i am doing some mistake

#

i get a wierd ans

pure hill
#

see when you substitute x with tan^2t then in denominator you can write 1+ tan^2 t as sec^2 t

#

then its all done

alpine sable
#

instead of tan sq t

pure hill
#

ohh that explains the weird answer

alpine sable
#

ya

#

thx bro

pure hill
#

alpine sable
#

"the equation 3x
2

  • kx − x + 3 = 0 has real roots."
#

Help

vale wigeon
#

did you mean 3x^2 + kx - x + 3 = 0?

alpine sable
vale wigeon
#

and what is the question? are you asked to find the values of k which make this true?

alpine sable
vale wigeon
#

yeah, ok, so you are asked to find the values of k that make this true

#

have you been able to do parts a through i?

alpine sable
#

Yeah

vale wigeon
#

then what's troubling you with part j?

#

it's much the same as all the otehrs

alpine sable
#

J, I need to do by myself

#

The A to I were done by others

vale wigeon
#

.-.

alpine sable
#

In class

vale wigeon
#

okay so then why did you answer "yes" to my question of "have you been able to do parts a through i?"

alpine sable
#

Cause I write 😎

vale wigeon
#

"i have done them myself" and "they were done in class and i copied them down without understanding" are two very different things.

#

anyway, whatever.

#

tell me, does the word "discriminant" ring any bells to you?

alpine sable
#

Idk

#

Me is too dumb

#

🍞

vale wigeon
#

so that's a no?

alpine sable
#

Ye

vale wigeon
#

does the expression b^2 - 4ac sound familiar at all?

alpine sable
#

No

vale wigeon
#

no? then how did you do it in class?

royal magnet
#

the difference between two numbers is 4 and six times the smaller is equal to four times the greater. find the numbers

#

can somebody help me in this? ⬆️

alpine sable
#

Nvm I got ot

split citrus
alpine sable
#

@vale wigeon

#

?

#

Just wanted to do some trolling

plucky radish
vale wigeon
brave thicket
#

hello, i need help in adding 1^2 + 2^2 + ... + 50^2

#

does anyone know a fast way on solving this and how?

vale wigeon
#

there happens to be a convenient readymade formula for the sum of the first n squares, actually.

brave thicket
#

i found a way of solving this, with this formula:

n(n+1)(2n+1) / 6

vale wigeon
#

yeah, that's what i was going to share now

brave thicket
#

however, idrk how that formula came to be

#

do you know how that formula was made?

vale wigeon
#

there are many ways to arrive at it

#

are you comfortable with big sigma notation? i might be able to show you one way to derive it.

vale wigeon
#

excellent

#

so what we're looking for is an expression for $\sum_{k=1}^n k^2$

ocean sealBOT
vale wigeon
#

what i will start with is this: $\sum_{k=1}^n (k^3 - (k-1)^3) = n^3$

ocean sealBOT
vale wigeon
#

does this require explanation?

brave thicket
vale wigeon
#

i'm writing out the following sum:
1^3 - 0^3

  • 2^3 - 1^3
  • 3^3 - 2^3
  • ...
  • (n-1)^3 - (n-2)^3
  • n^3 - (n-1)^3
#

notice how, when the sum is written out this way, a lot of terms cancel out

#

this is deliberate, of course

#

after you cancel everything out, all that remains is n^3 - 0^3, or just n^3.

#

does this make sense?

brave thicket
#

yes

vale wigeon
#

okay, great

#

now if you expand and simplify k^3 - (k-1)^3, you get 3k^2 - 3k + 1

#

let me just double-check that...

#

,w simplify k^3 - (k-1)^3

vale wigeon
#

okay yeah

#

so we have $\sum_{k=1}^n (3k^2 - 3k + 1) = n^3$

ocean sealBOT
vale wigeon
#

in other words, $3 \sum_{k=1}^n k^2 - 3 \sum_{k=1}^n k + \sum_{k=1}^n 1 = n^3$

ocean sealBOT
vale wigeon
#

do i need to continue or can you see it already?

brave thicket
vale wigeon
#

alright

#

you know that $\sum_{k=1}^n k = \frac12 n(n+1)$, right?

ocean sealBOT
brave thicket
#

yes

vale wigeon
#

and $\sum_{k=1}^n 1 = n$, of course.

ocean sealBOT
vale wigeon
#

so now we have: $$3 \sum_{k=1}^n k^2 - \frac{3}{2} n(n+1) + n = n^3$$

ocean sealBOT
vale wigeon
#

it's a matter of simple algebra from here on out.

#

@brave thicket

brave thicket
#

any other simpler way of arriving to the formula? i might need an easy way to explain the formula to a friend

vale wigeon
#

hmm

#

i remember seeing a geometric demonstration somewhere but idr what it was

brave thicket
#

alright then, thanks for the help once again

alpine sable
#

@pure hill

#

@vale wigeon

#

<@&286206848099549185>

#

how to prove onto?

vale wigeon
#

@alpine sable you should not ping random people out of the blue like this

alpine sable
#

kk

#

pls help tho

hexed viper
#

Graph it

alpine sable
#

we r supposed to prove that it is invertable

hexed viper
#

It’s obvious if you graph it

noble sinew
#

You need to show that for all x and y that f(x)=f(y) implies x=y. So start with suppose f(x)=f(y) and then try to deduce x=y

#

its not a proof to graph it

hexed viper
#

Graphing makes how to prove it obvious

noble sinew
#

Need to show for every y there is an x such that g(x)=y. So let y be arbitrary (in (-1,1)) and try to find a correct x

alpine sable
#

i get x=-y/1-y

hexed viper
#

You can either use a continuity argument with intermediate value theorem and limits or split it into cases of x being positive and negative and manually invert it in those cases

alpine sable
#

and x=-y/y-1

#

what am i to do then?

#

@noble sinew

noble sinew
#

not sure how you got x=-y/(1-y)

#

but once you get the correct 2nd solution then you have a correct value for x when y>=0 from one equation and another equation for when y<0

#

and you have proven onto

barren plover
#

is this correct

#

pls ping w answer

wary stream
#

Looks right

barren plover
#

just cuz it loosk right doesnt mean it is

#

ru sure

#

@wary stream

wary stream
#

Are you sure it's right?

barren plover
#

im not

#

thats why im asking u

#

obv

wary stream
#

Well, what's the formula?

barren plover
#

i have no idea lol

#

i guessed

alpine sable
#

A tangent and a secant

wary stream
#

It's a tangent and chord

alpine sable
#

its a secant sully

wary stream
#

Secant is a line, in that diagram, it's a line segment, therefore chord

slate heron
alpine sable
#

I think so, that's why I am not helping lol

barren plover
#

a secant is a line that intersects it twice ykyk

#

bro why does everyone in this servr

#

think that

#

i am not cheater 😠

alpine sable
#

because it looks like that

slate heron
#

because youre afraid of inputting any answer without 100% confidence

alpine sable
#

I mean it has been enough time I dont think it is a test anymore

wary stream
#

And submit it

barren plover
#

yea bcuz its like a practice test before i take my final test tomorrow

#

if i score below an 80 on it

#

i dont get access to the final

#

until 6 hours before it closes

slate heron
#

practice for the next 5 hours, take the test in the final 1 hour

#

if you cant do the practice test without help online, it probably wont get you a much better grade for the final

barren plover
wary stream
#

And if you have to confirm your answers, it proves that you're not confident in your knowledge of that concept meaning more studying

alpine sable
#

in that case I guess its fair

barren plover
#

i looked through my notes to get the answer to this but theres nothing for a question like this

#

i juts used a protractor and guessed

alpine sable
#

Its a secant and a tangent intersecting

#

I guess you must have learnt something relating to that

#

what happens when 2 chords of a circle intersect?

barren plover
#

i thought i remembered problems that look like that but they r nowhere in my notes so idk

alpine sable
#

what is the angle formed at the point of intersection?

barren plover
#

uhh

#

i am sutpid cry_about_it

alpine sable
#

well go through your notes again then

#

tommorrow is your exam

wary stream
#

It's there

alpine sable
#

it would be safe to assume SR as a chord tbh

#

tangent chord is what you need

#

@wary stream you were right

wary stream
#

Told you it's a chord

barren plover
#

its not doe

alpine sable
#

it is a chord too and a secant too

barren plover
#

i guess so

#

yea

alpine sable
#

i guess you have the answer now

barren plover
#

huh

#

how lol

wary stream
#

Secants are lines

alpine sable
#

Angle formed by a chord and a tangent intersecting is 1/2 of the arc

wary stream
#

Chords are line segments

#

That is a line segment

#

Therefore is a chord

alpine sable
barren plover
#

wait so was i right

#

i think im right

#

yes

alpine sable
#

Yes

barren plover
#

YAYAY

#

OKAY

#

TY

alpine sable
wary stream
#

Well guess it's a secant that's a chord

alpine sable
#

you can't just say that because its a line segment on a circle, its a chord

alpine sable
slate heron
#

yeah i think it's a tangent and a secant

pure hill
#

the answer to this problem is given -10 can someone explain why it will not be |10| instead?

gray gorge
#

If x is negative, can the expression be positive?

pure hill
#

but it gets cancelled out won't that mean there will be no effect of the sign on the answer?

copper gust
#

1/(1+x^2) ≤ a. ; what happens to the inequality when i sqrt

pure hill
#

can you tell me the procedure you used for this problem?

gray gorge
#

Well, how did you arrive at an answer of +10?

pure hill
#

I took x^2 from the numerator and cancelled it with x in the denominator

alpine sable
#

$n_{1}(2n_{1}-1)+n_{2}(2n_{2}-1)+n_{3}(2n_{3}-1)+n_{4}(2n_{4}-1)+...+n_{i-2}(2n_{i-2}-1)+n_{i-1}(2n_{i-1}-1)+n_{i}(2n_{i}-1)$

And,
$n_{i}=n_{i-1}+1$

Say,
$n_{1}=1$

Can we somehow formulate this in terms of $n$?

ocean sealBOT
#

IDrinkWine

alpine sable
#

And, $n_{i}=10$

ocean sealBOT
#

IDrinkWine

gray gorge
pure hill
#

thanks a lot

gray gorge
#

Np

eager badger
#

Hello, I'm not sure how best to describe this but I'm looking for algorithm to find an optimal bijection between two sets of 2D points, I have tried something with munkres-kuhn hungarian algorithm and fiddled around with the norm i used for the distance between points, but it doesn't look clean for, say, more than 500 points. Here's my result so far

#

i want my result to have "no intersections"

#

you can tell this version is working because some clusters move together, and the shape is still rectangular during the transition

#

also there may be somewhere better for this sort of question but I didn't really know where else to go

robust phoenix
#

x=9-3÷1÷3+1 how do we solve it ?

#

x-1=9-3÷1÷3
=3x-3=9-3÷1
=3x-3=6
=3x=9
x=3
I know i have a problem i just don't know what is it

vale wigeon
#

you're completely ignoring the order of operations here

#

x-1=9-3÷1÷3
=3x-3=9-3÷1

#

this move is illegal and also unnecessary

robust phoenix
vale wigeon
#

$9 - \frac{3/1}{3} + 1$ can and should be just evaluated as normal.

ocean sealBOT
robust phoenix
#

so how should i solve it

#

x-1=9-((3/1)/3)

vale wigeon
#

no

#

you're overthinking it again

#

are you not able to calculate 9 - (3/1)/3 + 1

#

by doing arithmetic

#

step by step?

robust phoenix
#

i am

vale wigeon
#

so what's the problem?

robust phoenix
#

no i am but i want to solve it in steps like the one above

vale wigeon
#

not worth the effort.

robust phoenix
#

Yeah

robust phoenix
vale wigeon
#

sure...

robust phoenix
vale wigeon
#

what is the goal here? to find the area of the region marked with S?

robust phoenix
#

yes

vale wigeon
#

okay

#

have you made any progress so far?

robust phoenix
#

yeah

vale wigeon
#

would you mind sharing?

robust phoenix
#

i was just expanding my field of view

vale wigeon
#

i have to say, this problem looks nasty

#

maybe it is possible to do it by coordinate-bashing

robust phoenix
#

what do you mean by nasty, nasty as good or bad lol

vale wigeon
#

i thought 'nasty' was an unambiguously negative descriptor...

robust phoenix
#

well yeah but sometimes it isnt i like nasty problems

#

oh i think i got it

#

idk if it may help but sure

vale wigeon
#

that 4.72 is almost certainly inexact.

robust phoenix
#

i used the pythagorean theorem

vale wigeon
#

and you took the root of something.

#

and your calculator gave you a decimal approximation.

#

anyway, idk about you, but this is how i would begin.

robust phoenix
#

yeah its 4.71 something

#

but i did it by my mind tbh

golden arch
#

What am I doing wrong?

golden arch
vale wigeon
#

@golden arch channel busy please move

#

the process that springs to mind right now is:

  • write down the coordinates of every point i can
  • write down the equations of lines OF and CE
  • find the coordinates of K and L
  • use the above data to find the length of LF and the altitude of triangle KFL originating from K
robust phoenix
#

OF is about 5.4

vale wigeon
#

why are you so insistent on decimal approximations?

#

also i didnt say to find the length of OF

#

i said to find the equation of the straight line going through O and F

robust phoenix
#

ohhh

vale wigeon
#

which in this case will be $y = \frac{2}{3}x$

ocean sealBOT
robust phoenix
#

and i don't use a calculator i use my mind

alpine sable
#

Hi, i need help from a question from calculus 3. Its about directional derivatives and finding the gradient of f.
This is the question from webassign, and couldn't understand what i did wrong.

#

I took the partial derivative for x and y respectively and plugged it into the calculator and got the unit vectors of <-48,72>, but somehow its wrong?

vale wigeon
#

<-48, 72> is not a unit vector.

#

they ask for a unit vector, i.e. a vector whose length is 1.

alpine sable
#

i forgot, what was the formula for the unit vector?

vale wigeon
#

...divide the vector by its own length

#

that's how you scale it down to length 1

#

how else?

novel lintel
#

a <= b means a < b or a = b

alpine sable
#

oh i got it

robust phoenix
novel lintel
#

So if I know a < b, can I conclude that a <= b

vale wigeon
#

yes

novel lintel
#

but

#

ikd

#

seems odd

#

idk*

#

I mean a neq b but it is smaller

#

seems like cheating lol

alpine sable
robust phoenix
vale wigeon
#

@alpine sable yes, that's what i said.

novel lintel
#

got it

vale wigeon
#

muhannad is misleading you a bit here.

#

yes, you can conclude a ≤ b if you know a < b.

#

it doesn't work the other way around, of course.

robust phoenix
vale wigeon
#

nobody says that

robust phoenix
#

huh

vale wigeon
#

a ≤ b doesn't mean "there is a scenario in which a = b"

robust phoenix
#

it means or

vale wigeon
#

yes, it means "a < b or a = b"

robust phoenix
#

oh i think you are correct

#

OR gate

vale wigeon
#

yes.

robust phoenix
vale wigeon
#

????

robust phoenix
#

your math level is great

vale wigeon
#

i mean... thanks ig

#

i'm not going to share my entire life story here lmao

robust phoenix
vale wigeon
#

please don't reply-ping me so much.

#

it's a bit annoying.

robust phoenix
flat vale
#

What do we call a particular character in an equation?
e.x

2 * x + 5

#

is there a word for 2, x and 5?

#

same word

#

not coefficient, pronumeral

dawn bison
#

terms?

flat vale
#

thanks!

#

what about + and *

#

can that be term as well?

#

not operator?

dawn bison
#

2 * x is 2x. so 2x is a term. the terms of the expression you gave would be : 2x and +5

novel lintel
#

oh so if a < b then a <= b

short turtle
#

quick question, is sin4x the same as 2sin2x?

#

okok i just suddenly forgot thinking it can be 2sin2x

ocean sealBOT
#

balance

alpine sable
#

very simple question, but

#

is 2-(5*(the square root of 9) )considered a perfect square?

vale wigeon
#

$2 - 5 \sqrt{9}$?

ocean sealBOT
vale wigeon
#

...why isn't the bot here

alpine sable
#

2-(5*sqrt9)

vale wigeon
#

so... -13

alpine sable
#

technically you can fully simplify it

#

but does that make it a perfect square

#

or no, because if you reverse factor it

vale wigeon
#

no, hiding it behind obfuscation like this does not change whether or not your number is a perfect square.

#

being a perfect square isn't a matter of 'consideration' either.

#

there is no integer that gives -13 when squared.

alpine sable
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well thats why its i

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but while sqrt(25*9) might be a perfect square

vale wigeon
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it isn't.

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sqrt(25*9) = 15

alpine sable
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25*9 is 225

vale wigeon
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sqrt(25*9) = 15

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15 is not a perfect square.

alpine sable
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wait im so confused

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what makes it a perfect square

vale wigeon
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what makes what a perfect square?

alpine sable
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2-5*sqrt9 is a perrfect square

vale wigeon
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what?

alpine sable
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is it?

vale wigeon
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no it's not.

alpine sable
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why not

vale wigeon
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-13 isn't a perfect square!

alpine sable
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oh

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its what you get at the fully simplified version of the equation

alpine sable
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nothing squared is negative

vale wigeon
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you're acting as if 2 - 5*sqrt(9) and -13 aren't one and the same...

vale wigeon