#help-36

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fading berry
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@fading berry Has your question been resolved?

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wanton pine
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how do i solve for the values of x in the equation $e^x(1+x)=1-x^2$

soft zealotBOT
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Galaxy

dry light
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Move everything to one side, then factor 1+x

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So $e^x(1+x) - (1-x^2) = 0$

soft zealotBOT
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Umbraleviathan

dry light
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Factor out 1+x from both terms

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vale reef
#

I’m not sure how to use the Pythagoras method

vale reef
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Do u plot (1,1) on a graph and make a triangle to start?

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After that i get confused tho

trim crown
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you can just focus on unit vectors

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as they uniquely determines the matrix

vale reef
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Hmm

trim crown
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so first find where x-unit vector goes to

vale reef
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To 0?

trim crown
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no

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it gets rotated 45 degrees

vale reef
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Fuck wait

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Oh I thought its root 2 but its not idk why its root2/2

trim crown
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root 2 is approximately 1.414

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it's longer than the hypotenuse

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2x^2=1
x^2=1/2

final saddleBOT
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@vale reef Has your question been resolved?

chrome cove
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Can you tell what the module of the vector you are trying to find is supposted to be?

vale reef
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Wdym

tulip coyote
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@vale reef Has your question been resolved?

vale reef
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Idek

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I’m gonna back to this

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hallow idol
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hi my channel just got closed

final saddleBOT
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Please don't occupy multiple help channels.

hallow idol
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.close

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empty leaf
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hi

final saddleBOT
empty leaf
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.close

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unreal anvil
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please do not troll.

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nova wasp
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nova wasp
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I'm stuck on b and c , part a was simialr but didn't have the inequality but rather a equality sign
I solved it using the theorem that says the amount of solutions is ( n + r -1 choose r)
I can't apply it this scenario

fallow wren
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@nova wasp Has your question been resolved?

nova wasp
fallow wren
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my previous question was refered to part a)

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tender jewel
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can anyone help me get started on this one?

vital crag
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Uhhh what theorems have you learned

tender jewel
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cauchy integral formula

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|integral| <= ML

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inequality

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maximum modulus theorem

tender jewel
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but at the same time that doesnt show f is necesarily a polynomial

final saddleBOT
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@tender jewel Has your question been resolved?

tender jewel
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<@&286206848099549185>

tardy fox
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Hey there. How is it going man?

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What you got here. Lez see

tender jewel
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im doing good

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@tender jewel Has your question been resolved?

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@tender jewel Has your question been resolved?

tender jewel
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/close

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.close

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brazen quest
final saddleBOT
brazen quest
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by taking limits on both side how we are getting the result?

desert mantle
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you have to show lim n->infty of U(...)-L(...)=0

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you have 0 <= U-L <= 1/n

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squeeze theorem

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0 <= lim U-L <= 0

brazen quest
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its not <=1/n

desert mantle
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< 1/n

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whatever. same thing

brazen quest
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ig not

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0<=U-L<0+ right after taking limits

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how we are concluding it will be 0

scarlet sequoia
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Second, when unneeded to know if 0 is 0+ or 0-, we just write 0 as the limit

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So 0 <= U-L <= 0

brazen quest
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yeah i dont have issue with writing 0 but its less than 0

scarlet sequoia
brazen quest
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can you explain bit about this

desert mantle
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0 <= 1/n^2 < 1/n

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if you take limits you still get 0 <= lim 1/n^2 <= 0

brazen quest
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hm i get this thing after taking limits it become large inequalities so we took <= sign

desert mantle
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or an even easier example of course, 0 < 1/n but if you take limits you get 0 = lim 1/n

brazen quest
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yeah i got that point

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but can you tell why strict inequalities become large inequalities

scarlet sequoia
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If an <= bn, the theorem of limits of inequalities states that lim(an) <= lim(bn)

desert mantle
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what do you want to hear for "why". I gave you two examples of why it cannot keep <

brazen quest
brazen quest
desert mantle
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ok are you confused about why it keeps some form of inequality at all?

scarlet sequoia
scarlet sequoia
brazen quest
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but here we are proving right

brazen quest
scarlet sequoia
brazen quest
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but its not false

desert mantle
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yes it is

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I gave two counterexamples

brazen quest
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i got ur point btw thanks

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hidden kiln
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.

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can someone help me pls with this quesiton pls?

hidden kiln
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can someone share their answers for this question pls

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just to check with my answer

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my answer: ||Mr Greenwell||

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@hidden kiln Has your question been resolved?

hidden kiln
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<@&286206848099549185>

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@hidden kiln Has your question been resolved?

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thick herald
final saddleBOT
thick herald
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Today with my teacher we were studying on finding the smallest and largest function in a given interval

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And i struggle to remember how we found this f(4)

urban maple
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You just plug $4$ into $f(x)$

soft zealotBOT
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OssihLikesBlue

thick herald
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so it's like my x is 4

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ahhhh i get it now, that's why we use the given interval to find it

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thanks a lot!

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tranquil pine
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wouldn't the x-intercepts of x(x+5)=0 be 0 and -5?

tired walrus
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you mean the solutions?

tranquil pine
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answer for this is x=-5

tired walrus
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or x-ints of y = x(x+5)

tranquil pine
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solutions i mean

tired walrus
tranquil pine
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no

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I factor it out to be x(x+5)=0

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but for some reason only -5 was accounted for

thorn grotto
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Try plugging x = 0 into the original equation

tired walrus
tranquil pine
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0 does not equal 0

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hmm

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weird

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then why do people regard x to be (x+0) and take it as a solution

thorn grotto
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0 / 0 is not 0

tranquil pine
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or is that only if it would work in the original function?

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so say the original function didn't have 0 in the denominator

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would 0 be a solution?

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@thorn grotto

thorn grotto
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If the equation was 2x/5 = x^2 - 5x, then 0 would be a solution

tranquil pine
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okay

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makes sense

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thanks

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acoustic finch
#

I have been taught to solve this problem by using trig substitution and letting x = 5sin(theta); theta element of [-pi/2, pi/2]. Would it theoretically be possible to instead say: x = 5cos(theta); theta element of [0, pi]?

acoustic finch
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weary canopy
#

how do i do this limit without using l'hopital?

weary canopy
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x-> negative inf of (x^3 + 2x -1)/(1-x^4)

urban maple
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Why would you need L'hopital here?

weary canopy
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my point is to not use it

urban maple
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fair enough but it's not really related

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anyway

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what do you know about limiting behaviour?

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or end behaviour?

acoustic finch
weary canopy
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FIASIOFHAIOSFH

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I FORGOT ABOUT THAT LMAO

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THANKS

acoustic finch
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lmao all good

weary canopy
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I've been using l'hopital for so long

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i just forgot all limit techniques lmao

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echo sinew
#

Need help with proportion if any ones free

final saddleBOT
echo sinew
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It’s pretty simple iirc

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I have 10000 ppl being 45% out of 100%

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How do I figure out the 55% like the number

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Do I do 10000/45?

warm ether
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many ways, most directly 10000/x=45/55 ie (10000/45)=(x/55)

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or find 5% and multiply by 11 or something

echo sinew
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So I would do

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500x11

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Being

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10500

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erm

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Let me verify

warm ether
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where did 500 come from

echo sinew
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nvm I confused myself

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Okay lemme re explain it I think I explained it bad

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45% is 10000
I’m trying to find the number that would be 55%

warm ether
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ik

echo sinew
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If j do 10000/45 it comes out as 22

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Does this mean the 55% is 22000?

warm ether
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22?

warm ether
echo sinew
warm ether
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that isnt 22

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that 222.222222222222...

echo sinew
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Oh I thought I should always take the 2 first numbers

warm ether
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what?

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why

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that would still be 220 even if i ignore the silliness

echo sinew
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Ohh

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Wait but how do I figure it out then???

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Sorry I’m awful at this…

warm ether
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its okay

warm ether
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that ^ or finding 5% then multiplying

echo sinew
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First one

warm ether
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alrighty
as a ratio
the whole number can be written as 10000/0.45 since 0.45(number)=10000 is 45% of said number

say x is 55% then x/0.55 is also the whole number

so we can say 10000/0.45 = x/0.55
i multiplied both sides by 1/100 for the fun of it before since it doesnt matter but this is what we have

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from there you just solve for x

echo sinew
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I have a question then, so why does the 222…. Show up when 10000/45?? Would that be part of the calculation??

warm ether
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it can be
10000/0.45 = x/0.55 is the same as 10000/45 = x/55

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no real difference

echo sinew
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To solve for x what should I do then??

warm ether
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what do you think?

echo sinew
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0.55 x 100

Then the result of that x 10000?

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Nvm that makes 550000

warm ether
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theres no particular reason to multiply by 100

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how would you get x=...
from 10000/0.45=x/0.55

echo sinew
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So sorry for this again but I don’t know

warm ether
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how could you solve $a=\frac{x}{b}$ where a and b are just some numbers

soft zealotBOT
#

AℤØ

echo sinew
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I’m really confused rn, let me try and explain what I know

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I know that na: would be 10000 + 55%

Ne: would be 10000
And p would be 45

So to find na they tell me do 10000/45 but then the same issue comes up where its 222.22222222…

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Is that how you do it normally??

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To find na?

warm ether
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what are ne and na

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and why is 10000/45=222.222 an issue?
10000/45=222.2222...=x/55

echo sinew
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They taught me that na is the total number, and ne is the number that are being experimented on basically

15 would be the ne of 30 (na) which 15/30 would be 50%

echo sinew
warm ether
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i never said it was

echo sinew
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Ohh

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Wait

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I think I understand it

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So now I multiply it by 100 to make it inline with the other numbers?

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And then the total would be

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22222 + 10000?

warm ether
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idek what you did

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stop thinking about 100

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theres no way for you to get an addition from this

echo sinew
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Alright

echo sinew
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I just tried another way rq

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Since 45 is 10000 I multiplied 10000 twice to get 90

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And then I just found 10% of 20000 which is 2000

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And that would add up to 22000

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Would that work?

warm ether
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i mean, no, that would be 54%

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if youre going to go about it that way, why not just get 5% and multiply by 11
or get 1% and multiply by 55 or something?

echo sinew
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Uhhh, can you explain the 5% way then if that’s possible

warm ether
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if 45% is 10000, what is 5%

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just leave it as a fraction

echo sinew
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I’m sorry this takes so long I’m just uh

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Really bad at this

warm ether
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its okay, take your time dw about it

echo sinew
#

Wouldent it be 500?

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Or are you asking for 5% of 45%

warm ether
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how do you get to 5 from 45?

warm ether
echo sinew
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45/9?

warm ether
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yeah exactly, you divide by 9

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so what is 5%

echo sinew
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900?

warm ether
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not quite

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if 45%=10000, and you divide by 9 to get 5% then 5%=10000/9

echo sinew
#

Should I divid

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Oh

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Then 5% of 10000 would be

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1111

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?

warm ether
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yeah but im against rounding until you finish

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just leave it as 10000/9 for now

echo sinew
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Alright

warm ether
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how would we now get 55%?

echo sinew
#

Multiplying the result of 10000/9 6 times?

warm ether
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why 6?

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that would be 30%

echo sinew
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Wait sorry I got confused

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11*

warm ether
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its alright

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yup, 11

echo sinew
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So 55% is 1111 x 11 which is: 12221

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Is that correct??

warm ether
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roughly, but use exact values

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,calc 10000/9 *11

soft zealotBOT
#

Result:

12222.222222222
echo sinew
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So I do 12222.222222222 + 10000?

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To find 100%

warm ether
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i guess that works, sure

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could just do 10000/0.45

echo sinew
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Oh

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So the exact answer is about

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22222?

warm ether
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,calc 10000/0.45

soft zealotBOT
#

Result:

22222.222222222
warm ether
#

ish

echo sinew
#

Alright, thanks a lot

warm ether
#

np

echo sinew
#

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supple nest
final saddleBOT
supple nest
#

i have never been so stuck on a problem before

#

i dont know what the issue is for me

tender jewel
#

,tex $\int_1^{e^x} ln(u^5)du = F(e^x) - F(1) $

soft zealotBOT
#

epiphonically

tender jewel
#

,tex then ${d \over dx} \int_1^{e^x} ln(u^5)du = {d \over dx} F(e^x) - {d \over dx} F(1) $

soft zealotBOT
#

epiphonically

supple nest
#

see i dont know what this means is the issue

tender jewel
#

,tex ${d \over dx} F(e^x) - {d \over dx} F(1) = f(e^x) {d \over dx} e^x - 0$

soft zealotBOT
#

epiphonically

supple nest
#

could you try to put this into simpler terms lol

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before, i just had the lower boundary as 1 and the upper boundary as x

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so for the answer i could just enter the function given

tender jewel
#

,tex do u know that $\int_a^b f(x) dx = F(b) - F(a)$

soft zealotBOT
#

epiphonically

supple nest
#

yes

tender jewel
#

,tex do u agree then $\int_1^{e^x} f(x) dx = F(e^x) - F(1)$

soft zealotBOT
#

epiphonically

supple nest
#

i guess that would make sense yes

tender jewel
#

,tex Then ${d \over dx} \int_1^{e^x} f(x) dx = {d \over dx} F(e^x) - {d \over dx} F(1)$

soft zealotBOT
#

epiphonically

supple nest
#

let me show you where i get hung up

tender jewel
#

kk

supple nest
#

so with this problem

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why would that not be e^(-x^7)-e^(-2^7)

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wait

tender jewel
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when you differentiate the constant term goes away

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to 0

supple nest
#

is it because d/dx(F(1)) is 0

tender jewel
#

yea

supple nest
#

so its just taking the derivative of ln(e^x)^5)?

tender jewel
#

not exactly

supple nest
#

or like

tender jewel
#

,tex its $ln(e^{5x}) \cdot {d \over dx} e^x$

supple nest
#

oh wait

soft zealotBOT
#

epiphonically

supple nest
#

because its continuous

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and F'(x) is just f(x)

tender jewel
#

yes

supple nest
#

would the answer just be 5ln(e^x)

tender jewel
#

no

supple nest
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but f(x) would be ln(e^x)^5)

tender jewel
#

,tex u wanna find ${d \over dx} F(e^x) $

soft zealotBOT
#

epiphonically

supple nest
#

thats just e^x right

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oh wait

tender jewel
#

no

supple nest
#

d/dx ((e^5x))

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so

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5e^5x

tender jewel
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,tex ${d \over dx} F(e^x) = f(e^x) e^x$

soft zealotBOT
#

epiphonically

tender jewel
#

using chain rule

supple nest
#

e^x * 5e^5x?

tender jewel
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no

#

,tex f(x) in the problem is $\ln(x^5)$

soft zealotBOT
#

epiphonically

supple nest
#

e^x (5x^4/x^5)

tender jewel
#

no

supple nest
#

wait

#

no im dumb

#

5/x

#

e^x(5/x)

#

5e^x/x?

tender jewel
#

not quite

#

,tex $\ln\left(e^{5x}\right)e^{x} = 5xe^{x}$

soft zealotBOT
#

epiphonically

supple nest
#

so that would be the answer

tender jewel
#

yes

supple nest
#

ok

#

oh yeah

#

i forgot i wouldn't need to take the derivative of ln(x) because thats already the derivative

#

ok i dont know why that took me so long tysm

#

i think the introduction of another function totally threw me off

#

.close

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quiet holly
#

Let A ⊂ R be non-empty. If A has a supremum but no
maximum, then for every ε > 0 there are infinitely many a ∈ A with
sup (A) - ε < a < sup (A).

quiet holly
#

guys

#

how prove this question <@&286206848099549185>

#

hepl plz

final saddleBOT
quiet holly
#

sorry homie

tired walrus
#

!status

final saddleBOT
#
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
quiet holly
#

didn't know

tired walrus
#

well now you do

quiet holly
tired walrus
#

ok

#

If A has a supremum but no maximum, then for every ε > 0 there is at least one a ∈ A with sup (A) - ε < a < sup (A).

#

i've replaced the "infinitely many" with "at least one" in this statement

#

do you know how to prove this one?

quiet holly
#

lemme think

tired walrus
#

(yes, it's weaker. but trust me, it's a stepping stone towards the real thing)

quiet holly
#

one sec

#

does it have anything to do with proving by induction ?

tired walrus
#

not really, no.

quiet holly
quiet holly
# tired walrus not really, no.

ok it makes sense. Sup(A) - ε is itself in set A as it is a value that is smaller than the supremum yet it exists in the set A. Right?

tired walrus
#

Sup(A) - ε is itself in set A
incorrect

quiet holly
tender jewel
tired walrus
#

sure it belongs to A for some epsilons, but not for all of them.

quiet holly
#

ahh

quiet holly
#

would we use the fact that the set is non empty?

tired walrus
#

well

#

i wouldnt say so directly

#

the way i know how to prove that (∀ε>0)(∃a ∈ A)(sup(A) - ε < a < sup(A))

#

is by contradiction

#

if this werent the case, then sup(A) would be separated from the rest of A by a gap of some size (corresponding to the epsilon for which there does not exist any a)

#

and we can't have that, bc then the supremum would not be the supremum.

quiet holly
#

huh

#

ok

tired walrus
#

so then you can say

#

each interval of the form (sup(A) - 1/n, sup(A)) contains at least one point of A

#

and these fuckers are nested

#

so within each one theres actually infinitely many points of A bc of that.

quiet holly
#

would that be a valid proof to show that at least one element exists in the set A between sup(A) - ε and sup(A) ?

tired walrus
#

and lets assume that sup(a)-ε is not ∈ A. then we would conclude that then, Sup(A) would actually not be the supremum of set A
no

#

sup(A) - ε ∉ A by itself doesnt place a gap between sup(A) and A.

#

or.

#

ok fuck your wording of it is clunky sorry

quiet holly
#

lemme try to reword it

tired walrus
#

im going off to sleep

#

ive said everything i wanted to say and i dont have the energy to pick through and unclunk wording

quiet holly
#

ok

#

well

#

thanks for the help eitherway

#

<@&286206848099549185> Can someone help with this question? The previous helper went to bed. opencry

final saddleBOT
#

@quiet holly Has your question been resolved?

tender jewel
soft zealotBOT
#

epiphonically

tender jewel
#

since sup(A) - ε is not an upper bound

soft zealotBOT
#

epiphonically

#

epiphonically

#

epiphonically

#

epiphonically

tender jewel
#

and this repeats to infinity

final saddleBOT
#

@quiet holly Has your question been resolved?

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tranquil pine
#

How do I solve

final saddleBOT
tranquil pine
#

Do I have to foil it all out

toxic arch
#

It's easy to factor bc the constant terms cancel

tranquil pine
#

Not really sure how id convert that to interval notation tho

toxic arch
#

Bc 9 is on RHS

#

not 0

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gaunt shadow
#

I need my work checked

final saddleBOT
gaunt shadow
#

I’ve gone through my work twice and I caught two mistakes but it’s still wrong

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#

@gaunt shadow Has your question been resolved?

gaunt shadow
#

<@&286206848099549185>

#

<@&286206848099549185>

#

<@&286206848099549185>

#

<@&286206848099549185> I need help

gaunt shadow
#

<@&286206848099549185>

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@gaunt shadow Has your question been resolved?

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hybrid sun
#

Can someone factorize this completely everytime i do it i get diffrent answers: 6p^2+7p-20

wraith crater
#

What’s ur answer

hybrid sun
tawny bluff
#

that's not a correct factorization, sadly

#

3p*-5 + 4*2p = **-**7p

hybrid sun
#

wym

heavy loom
#

double check your signs

hybrid sun
#

is it suppose to be subtract instead of + for (3p+4)

tawny bluff
#

yup

#

you can think of it this way:

#

the 2p*3p is correct, you get 6p^2

hybrid sun
#

yh but the teacher said factorize it completely

#

and in class she did smth abt

#

a b and c

#

value

#

idek how to get that

tawny bluff
#

the -(+4 * +5) = -20 is correct, so one of 4 OR 5 is negative

#

+4 and -5 gave -7 instead of 7, so flipping the signs will give -4 and 5 for 7

#

a b and c? You'll have to be more specific, sadly, as those are very common names for coefficients

#

unlike, say, m and b, which are more distinctive

hybrid sun
#

wait can i send you a screenshot of my classmates workout and u tell me if its wrong or right

tawny bluff
#

sure

hybrid sun
tawny bluff
#

genuinely not sure what they're doing

#

but a b and c seems to refer to standard quadratic form

#

ax^2 + bx + c

hybrid sun
#

yh

#

thats what we doing

#

the last line on left side suppose to be final answer

#

the other side i think

#

is the

#

values?

#

and factors

tawny bluff
#

as shown on the right, the issue is you get -7 for b

#

when your initial question had +7

#

on the second line they wrote it wrong

#

they expanded 7p into 8p - 15p instead of -8p + 15p

#

from there the mistake is preserved

#

make sense?

hybrid sun
#

ohh ok

#

so whats the correct answer

tawny bluff
#

well, the process is right

#

[6p^2+7p-20]
[6p^2-8p+15p-20]
[2p(3p - 4) + 5(3p - 4)]
[(3p - 4)(2p + 5)]

soft zealotBOT
hybrid sun
#

respect astral

tawny bluff
#

np

hybrid sun
#

ah bro you can close this now

#

or unoccupie it i mean

tawny bluff
#

.close

final saddleBOT
#
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tawny bluff
#

P:

#

have a good evening!

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wide folio
#

.close

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cedar copper
final saddleBOT
cedar copper
#

Hello

#

I have this one here

#

So i know some basics rule

#

that the exponenet will be in front and stuff like that

#

And that i will add 3 logs here

#

to expand it

#

But for example square root x alone will be x^1/2

#

how about when they have this exponenents

final saddleBOT
#

@cedar copper Has your question been resolved?

faint edge
#

You have a nested situation going on.

#

Easier to write then to type it. Gimme a sec.

#

,rotate

soft zealotBOT
faint edge
#

@cedar copper

#

From this point onward is just simplifying exponents and applying the rules of logs you mentioned.

#

The easiest way is to probably just work from the outside inward

cedar copper
#

Oh

#

Woah that look confuse

#

Ok

#

Ohhhh

#

those square roots on top of each other so 1/2 for 3 of them

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#

@cedar copper Has your question been resolved?

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pulsar patio
#

Ok so Im confused with how to find the interest on the second part.

pulsar patio
#

Im basically just asking for guidance in the right direction cause I got no clue

shadow aspen
#

How much you got from interest is however much more money you got since depositing

pulsar patio
#

Yeah I would calculate it by saying 36300 = PV PMT = 37,835.30 I/YR = 9.5 % P/YR = 1 N = 42

#

And then subtract 36300 from the total

#

but it would be wrong

shadow aspen
#

I do not understand these units at all. If I means interest though I can tell you 378535.30 I/yr is not right

pulsar patio
#

36300 is the present value, 37,835.30 is the payments per period, 9.5% is the interest rate, the periods is one per year, the N which is periods times time is 42

#

cause 42 times 1 is 42

#

thats my units

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#

@pulsar patio Has your question been resolved?

final saddleBOT
#

@pulsar patio Has your question been resolved?

sturdy cypress
#

you withdraw 37835 18 times and there's no money left

#

that's the total

#

37835× 18

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#

@pulsar patio Has your question been resolved?

magic sparrow
#

@robust mulch

robust mulch
#

Oh hi

magic sparrow
#

is this close enough

robust mulch
#

Bro stop pinging people

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wanton mortar
#

One student argues that a satellite in orbit is in free fall because the satellite keeps falling toward Earth. Another says a satellite in orbit is not in free fall because the acceleration due to gravity is not . With whom do you agree with and why?

wanton mortar
#

It would be in a freefall no?

neon slate
#

l because the acceleration due to gravity is not . --> typo here? what is that supposed to say?

wanton mortar
#

perhaps lol

#

but thats what im being asked lol 😂

neon slate
#

what, the problem just says that?

wanton mortar
#

yes just that

#

id say freefalling

neon slate
#

well it's hard to agree with that second student then : )

#

but yeah, objects in orbit are in general in free fall

wanton mortar
sturdy cypress
#

"the first student gives no reason, and the second student makes no coherent point at all"

wanton mortar
#

rofl

#

sounds like a good amount of students no

sturdy cypress
#

"I agree with the second student, it's not our job to explain physics"

wanton mortar
#

and thats just because the force of gravity

neon slate
#

definition of free fall is i think if there is no force acting on the object other than gravity

#

so is that true for the satellite?

wanton mortar
#

if it was a planet different story right?

neon slate
#

🤔

wanton mortar
#

they have tangetial velocity no?

#

or samething happening here?

neon slate
#

velocity doesn't imply a force is acting on an object, acceleration is what implies a force

#

that's the whole point of Newton's law of "an object at rest remains at rest, an object in motion remains in motion" unless a force is acting on it

wanton mortar
#

that makes sense

neon slate
#

i guess you can say technically a body is in free fall around the body it is orbiting, not sure if that is a useful description but whatever

#

even for something like moon around a planet or a planet around the sun

#

so yeah i'd agree with the first student

#

i think the main point to understand is an object in orbit only experiences the force of gravity, how you decide to describe that in words is a bit relative, no pun intended

wanton mortar
#

so from my understanding

#

what makes the circle

#

is that tangetial velocity

neon slate
#

ellipse*

#

😄

wanton mortar
#

true

#

lol

#

so where does this velocity come from with the satellite?

neon slate
#

well that depends how the body got into orbit, a rocket used its engines to gain velocity, the moon...we don't fully understand how it formed but either from the original momentum of the solar system forming or from some forceful impact with the earth and a chunk breaking off with enough velocity to put it in orbit

#

then when an object is in orbit, just gravity is acting on it and redirecting that velocity into a slightly different direction constantly

wanton mortar
#

"Considering that the only force that is being exerted on the satellite is the force of gravity I would agree with the first student that the satellite is in free fall this is because the satellite possessed enough initial tangential velocity to offset the free fall and produce perpetual orbit. "

#

coolin?

neon slate
#

perpetual orbit is a redundant term at best and incorrect / confusing at worst, the word orbit by itself implies revolutions around an object

#

so just strike out perpetual :p

wanton mortar
#

okay gotcha! thank you

#

yeah i thought it was in a freefall

#

i just couldnt exactly state how it was continue to move.

neon slate
#

just say, it has enough tangential velocity to keep missing the earth as it is falling

#

because thats basically what it is

wanton mortar
#

okay thats true!

neon slate
#

😄

wanton mortar
#

i appreciate helping me fully understand it! i knew they were not* spending thousands in gas to keep that thing having tangetial velocity.

neon slate
wanton mortar
#

to me it reminds me of a basketball when it goes around the hoop for awhile

#

kinda different ofc lol 😂

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#

@wanton mortar Has your question been resolved?

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rugged yoke
#

how did they get this?

final saddleBOT
rugged yoke
#

by the quotient rule, shouldn't it be $\frac{u(y)u'(x+y)-u(x+y)u'(y)}{u(y)^2}=0$?

soft zealotBOT
#

Kalgar

desert mantle
#

the x is just in the numerator

#

u(y) is a constant

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#

@rugged yoke Has your question been resolved?

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marble wing
final saddleBOT
marble wing
#

Hello guys what first derivative is correct in this case

marsh temple
#

The first

#

You seem to have forgotten about the +2x term in the second between these two lines

marble wing
#

Oh okay… thank you

#

.close

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marble wing
#

From 4e^x-x^2e^x

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marble wing
#

And how do I make stationary points from 4e^x-x^2e^x

marble wing
#

.close

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ivory lynx
#

hello, for letter a, how do i do the double angle identity for this? its not a special angle unfortunately

ivory lynx
#

22.5*2 = 45

neon slate
rich tide
#

sin(2x)=2sin(x)cos(x)

neon slate
#

its half angle identities not double angle here, but yeah you could derive one from the other

#

oh sorry yeah youre right @rich tide you can use the double one more easily for a

ivory lynx
#

how do u get sin 22.5 and cos 22.5

#

the exact values of it

rich tide
#

You don't need 'em

neon slate
#

x = 22.5

rich tide
#

By using the formula I gave, You can achieve sin of an angle that is pretty much known by everyone

neon slate
#

so 2sin(22.5)cos(22.5) = 2sin(x)cos(x) = sin(2x) = sin(45)

ivory lynx
#

OHHHHH

#

i see

#

thank

ivory lynx
rich tide
#

yes

#

tan(2x)=2tan(x)/(1-tan^2(x))

ivory lynx
#

thank you

rich tide
#

hol up

#

you don't have a square in the denominator tan

#

You need to manipulate it a bit

ivory lynx
#

damn

#

so its not tan 30?

rich tide
#

unfortunately no

ivory lynx
#

fuck

ivory lynx
#

how to get the value of 15 degrees

rich tide
#

well seems like you'll have to calculate the value of tan(15) for this

#

using tan(2x)=2tan(x)(1-tan^2(x))

ivory lynx
rich tide
#

well, we don't need one

#

we can calculate it by hand

ivory lynx
#

2 sqrt3

#

2 - sqrt 3

#

wait how tho

#

15 is not a special angle unlike 30 45 and 60

rich tide
#

$\tan\left(30\right)=\frac{1}{\sqrt{3}}=\frac{2\tan\left(15\right)}{1-\tan^{2}\left(15\right)}$

soft zealotBOT
#

B-eard

rich tide
ivory lynx
#

why

rich tide
#

I do wonder the same

ivory lynx
#

are multiples of 15 special ang

#

les

#

15, 30, 45, 60, 75?

rich tide
#

(extra: even 37,53 are standard angles. tan(37)=3/4, tan(53)=4/3)

rich tide
ivory lynx
#

ye

rich tide
#

18 degrees is also standard

#

back to the question

rich tide
# soft zealot **B\-eard**

let tan(15) to be another variable let's say y.
So, you have a quadratic in y which can be solved fr two values of y.
One of them will be rejected due to its sign (15 is in first quadrant and so tan of it must be positive)

rich tide
#

yes

ivory lynx
ivory lynx
#

because, as u said 15 is in first quadrant

#

ASTC

rich tide
#

well, no

ivory lynx
#

ah'

rich tide
#

$\frac{1}{\sqrt{3}}=\frac{2y}{1-y^{2}}\ ⟺\ y^{2}+2\sqrt{3}y-1=0$

soft zealotBOT
#

B-eard

rich tide
#

cross multiplication

ivory lynx
rich tide
#

now, do you know the quadratic formula?

ivory lynx
#

-b +- sqrt

#

b^2 - 4ac / 2a

rich tide
#

so, solve for y

ivory lynx
rich tide
#

yes

ivory lynx
#

ooooo perfect square

rich tide
#

are you sure?

ivory lynx
#

sqrt3^2 = 3

#

2^2 = 4

#

4*3 is 12

#

-4(-1) = positive 4

#

12 + 4 is 16

#

sqrt 16 is 4

#

and since 2 is ur denominator; therefore it will be

rich tide
#

Okay there was abit of misinterpretation

#

So you mean the discriminant is perfect square

ivory lynx
#

wdym discriminant

#

oh no

#

i mean ive heardf but i forgot

rich tide
#

Okay just proceed

#

to find the value of tan(15)

ivory lynx
#

consider the +-4 i did wrong in my next part

rich tide
#

well you are near the solution

#

recheck the last step (coefficient of sqrt(3) is not halved)

ivory lynx
#

can u cancel +- 4 and denominator 2

rich tide
#

you should end up with tan(15)=-sqrt(3)+-2

ivory lynx
#

or no

rich tide
#

Okay, so you would have tan(15)=2-sqrt(3) or tan(15)=-2-sqrt(3)
But as I said, one value would be rejected

#

just consider the other value and plug in

ivory lynx
rich tide
#

no

ivory lynx
#

ay wait

rich tide
#

But as I said, one value would be rejected

#

tan(15) should be positive

#

well I gtg now

rich tide
#

so if you have any questions, ask it real quick

ivory lynx
rich tide
soft zealotBOT
#

B-eard

rich tide
#

tan(15)=2-sqrt(3)

#

as per our calculations

ivory lynx
rich tide
ivory lynx
#

yeah

#

4sqrt3/11

#

am i doing it wrong

#

tis what i got

ivory lynx
final saddleBOT
#

@ivory lynx Has your question been resolved?

final saddleBOT
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spice rapids
#

Hi, i have a table of weight of sugarcubes. i have to calculate the chance that i only need two sugarcubes to get 9 grams of sugar. how do i do this?

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#

Please don't occupy multiple help channels.

spice rapids
#

.close

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rapid folio
final saddleBOT
rapid folio
#

how do i do this

final tangle
#

we're going to need the full question

#

(what's the original sequence)

rapid folio
final tangle
#

and did you do part a)?

rapid folio
#

6n-1

final tangle
#

what do you get when you square that and add 5?

rapid folio
#

wait so do u just do (6n-1)^2 +5?

final tangle
#

that'll be the general term of the new sequence

rapid folio
#

ohh okay

#

it will be 36n^2-12n+6

#

or 6(6n^2-2n+1)?

final tangle
#

yes

rapid folio
#

oh okay

#

thank you

#

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verbal steppe
#

$f^-1(f(x))$

final saddleBOT
soft zealotBOT
#

Merineth

verbal steppe
#

Where:

#

$f(x) = x ^2$

soft zealotBOT
#

Merineth

verbal steppe
#

Why is the answer x ?

#

.close

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muted ore
final saddleBOT
muted ore
#

How should I draw M?

desert mantle
#

can you find some points in M?

muted ore
#

I wrote it as a square with:

0,1 - 1,1
I I
0,0 - 1,0

desert mantle
#

yes

muted ore
#

I don't actually know how it should be explained?

desert mantle
#

well if you have any point in the square, then its x coordinate is between 0,1 and same for y coordinate

#

so M includes the square

muted ore
#

ah, okay

desert mantle
#

and if you have a point outside the square then either x or y coordinate is not between 0,1

#

so it is not in M

muted ore
#

but since its two vectors

#

can they be added together ?

desert mantle
#

two vectors?

#

where

muted ore
#

v1, v2

desert mantle
#

v1 and v2 are numbers

muted ore
#

oh

#

Then I was just confused by the lettering

#

normally v is chosen for vectors

desert mantle
#

¯_(ツ)_/¯

#

pretty normal to write something like v=(v1,v2)

#

v is a vector with the entries v1 and v2

muted ore
#

"Let gamma1, gamma2 in R and define.."

#

Draw L_a(M), which means the amount {...} in the following scenarios:

desert mantle
#

that letter is called lambda, not gamma

#

$\lambda$ and $\gamma$

muted ore
#

ah, lambda

soft zealotBOT
#

Denascite

muted ore
#

I don't know how to understand exercise B

desert mantle
#

so, you have to check where the square gets mapped to

#

first do it for the corners

#

so L_A(v) for v=corners

#

then for example middle of the edges

#

then some random point in the middle of M

#

and at some point you should see whats going on

muted ore
#

im not sure how to understand

desert mantle
#

what is L_A(v) is v is one of the corners

muted ore
#

lambda_1 = 1 and lambda_2 = 2

#

does that mean that I have to find the vector to times with A to get them in the corner 1,1?

desert mantle
#

no

#

less complicated

#

A times (1,1)

muted ore
#

textbook says (0,0)

#

for the first one

desert mantle
#

thats for A times (0,0)

muted ore
#

but why is (0,0) the answer

#

I don't understand

#
  1. lambda_1 = 1, lambda_2 = 1
#

why is the answer (0,0) here?

desert mantle
#

matrix vector multiplication

#

A is (1,0; 0,1)

#

v is (0,0)

#

if you multiply that you get (0,0)

muted ore
#

Yes

#

but we want lambda_1 = 1 and lambda_2 = 1

#

why would we want 0,0

desert mantle
#

yes

#

I plugged those into the diagonal

muted ore
#

oh

desert mantle
#

then took a corner of the square

muted ore
#

we have the diagnola

desert mantle
#

and checked where A maps it to

muted ore
#

we plug lambda_1 = 1 and lambda_2 = 1 in

#

so we get:

10
01

#

right?

desert mantle
muted ore
#

And we want to multiply with what ?

#

what is v1 and v2 in this case

desert mantle
#

0 and 0

muted ore
#

but how do you know that they are 0 and 0

#

its not stated that v1=0 and v2 = 0

desert mantle
#

the lower left corner of the square

#

we are taking some points in M and just check where they get sent to

#

next we will take another v

#

for example (v1,v2)=(1,0)

#

or (0,1)

#

or (1,1)

#

or some other point which isnt a corner

#

(0.5,1)

#

or (0.8, 0.3)

#

and so on

#

until we see whats going on

muted ore
#

lambda_1 = 1 and lambda_2 = 1

#

we get a matrix:
10
01

#

right?

#

and because we have the opposite diagonal (0,0), we get 0,0 ?

desert mantle
#

no no no

muted ore
#

could you draw it in like paint ?

desert mantle
#

I am on mobile

muted ore
#

oh

desert mantle
#

we have the matrix

#

10
01

#

that is fixed

#

we dont change it for now

#

and then we check what matrix* v is

#

where v is some vector in the square M

muted ore
#

mhm

#

a nd how do we find v?

desert mantle
#

and because we dont yet know whats going on we just try out some values for v

#

wr dont "find" it

#

theoretically we would have to do it for every v in M

#

but we just do it for a few and then we understand whats going on so we will skip the rest

muted ore
#

right, okay

#

so it should be set up as an equation?

desert mantle
#

no

muted ore
#

im just gonna draw the matrices now then

#

we have:

(0,0), (1,0), (0,1), (1,1)

#

in case 1 it means we have corners in (0,0), (1,0), (0,1), (1,1)

#

Or what ?

#

like can you show me calcuation/method for:
lambda_1 = 1, lambda_2 = 2
lambda_1 = 2, lambda_2 = 3
lambda_1 = -1, lambda_2 = 2

desert mantle
#

its the same method as for lambda_1=1, lambda_2=1

muted ore
#

But why does the teacher write "Corner point in (0,0)" as the answer to lambda_1=1, lambda_2=1

#

that answer does not make sense to me

desert mantle
#

the set that you are trying to figure out will again be a square

#

one of its corners will be in (0,0)

muted ore
#

right¨

#

all of this just gives a bunch of 2x2 matrices right? @desert mantle

desert mantle
#

what do you mean with "all of this"

muted ore
#

The answer says:
" It holds that... in several cases L_a(M) is a rectangle with corner points (0,0) (lambda_1,0), (0, lambda_2), (lambda_1, lambda_2)

#

I just don't understand what they wanted from me

desert mantle
#

finding out that the set will end up being a rectangle with those corners

muted ore
#

but how will the rectangle look with lambda_1 = 2 and lambda_2 = 3

#

won't it always be a 2x2 matrix ?

desert mantle
#

A will always be a 2x2 matrix, yes

#

but a different one each time

muted ore
#

right, I think I got it

desert mantle
#

and different matrices change space differently

muted ore
#

I basically multiply the original A with a set of vectors

#

and so we get for example a 2x3 square

#

with corners:

(0,0), (2,3), (2,0), (0,3)

#

And the idea is just to show that for all cases, it holds that:

(0,0) (lambda_1,0)... is the corner

#

right? x)

desert mantle
#

yes

muted ore
#

Okay, makes much better sense now

#

with M and A in R^2x2 as before ,check that the area of L_a... is the same as the determinant of A