#help-17

1 messages · Page 181 of 1

wild meteor
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0, 6 and 1, 8 right?

strange crater
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it's asking for the x-intercept, too

wild meteor
wild meteor
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how do you get from this step to that step

strange crater
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for the x-intercept you should be solving 0 = 2x + 6

wild meteor
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(i sent another question to ask)

strange crater
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just solve for x

wild meteor
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then

wild meteor
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-6=2x

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-3=x?

strange crater
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yeah

wild meteor
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is the points i mark?

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wiat no

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what do i mark on my graph

strange crater
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the two intercepts

wild meteor
strange crater
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the x and y intercepts

wild meteor
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so/?

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what is that

wild meteor
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so what do i mark

strange crater
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what do you mean? that is a point

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the other is (0, 6)

wild meteor
vocal sleetBOT
#

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vocal sleetBOT
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north python
vocal sleetBOT
north python
#

can someone help me with this, for some reason this isnt the answer

pale perch
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your method?

vocal sleetBOT
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@north python Has your question been resolved?

north python
#

for my equation

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but its not right

vocal sleetBOT
#

@north python Has your question been resolved?

vocal sleetBOT
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@north python Has your question been resolved?

north python
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teal pelican
#

how do i find the perimeter of this

vocal sleetBOT
dull wind
#

notice that total length of red lines equals to yellow line

teal pelican
#

yes

dull wind
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so what's next?

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what's the length if yellow line

teal pelican
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the length is 10

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of the yellow line

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/close

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finite hatch
#

hi

vocal sleetBOT
finite hatch
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some how my friend said im doing this wromg

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can i plz have some help

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he said i shouldve got 4 and -1

vital iron
finite hatch
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was for perpendicular

vital iron
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well when we cross product two parallel vectors the resultant is zero since the angle between them is 0

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and sin0 = 0

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so you should cross product and equate with zero

finite hatch
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can i not use the property of

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q = kp

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where k is a scale factor

vital iron
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sorry im unaware of that property

finite hatch
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because you know how parallel vectors

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the red can just be multipled by a scale factor to be the same as blue

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and they are parallel :D

vital iron
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4 and -1

strong grove
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@finite hatch ^

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u are to find value of m and not k

finite hatch
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ok thx

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rich sinew
#

Question 15: Points A and B have coordinates (2,0) and (6,0) respectively. Points C and D have coordinates (a,4) and (-a,4) respectively.

a) Find the equation of line AC in terms of a.

b) Find the equation of line BD in terms of a.

c) Find the coordinates of P the point of intersection of line AC and line BD in terms of a.

d) Prove that P lies on the line x+y=4

rich sinew
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i dont really want the answer for this

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its a question on an assessment task

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however i have spent an embarrasing amount of time on this question and am begining to question whether its possible or not

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so before i spend an even more embarrasing amount of time on it, i wanted to come here and make sure its possible

dull wind
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can you draw a coordinate system with the points A, B, C, D for me

rich sinew
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can you do that with unknowns?

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parts a b and c all make sense to me

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but there is no way P is on that line

dull wind
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now let's find the equation of line AC

rich sinew
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remember i dont want the answer

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i just need to know if its possible or not

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part d) in particular

dull wind
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after you find the coordinates of P

rich sinew
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in my working out i found P to be (a,4)

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i dont see how thats on the line

dull wind
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check if it satisfies x+y = 4

rich sinew
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not unless a=0

dull wind
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man bc the pic is wrong

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i'll draw again

rich sinew
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x=a, y=4

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it satisfys both equations

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but it dosent lie on x+y=4

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so im wondering if i made a mistake somewhere or if the question is written wrong

vocal sleetBOT
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@rich sinew Has your question been resolved?

rich sinew
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i have to go to sleep

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ill post question again tmr

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sly imp
#

I calculated the total number of possibilities and subtracted from it the number of possibilities where 2 girls do sit next to each other.

The real answer however is 1440, so ig I calculated the number of of possibilities where 2 girls do sit next to each other as too high? How so?

sly imp
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Don't need the answer to the question itself, just why my calculation was wrong

wary fiber
sly imp
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I calculated the the number of ways 3 girls could be randomly selected and arranged in 2 spaces as 3p2, then multiplied it by 6 cuz these 2 linked spaces can be in 6 spots in total, then multiplied that by 5p5 cuz the rest 5 people can be arranged in 5 spaces randomly

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Now that I think about it, another girl could still be on either side of the 2 girls standing next to each other by this calculation, or just one side when the linked spaces are on either of the farthest edges

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How would I account for that by this method?

wary fiber
sly imp
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Apparently calculated it as too high since subtracting it from the total gives a lower answer than the correct one

wary fiber
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true

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also you could just try another method overall since this may lead to some errors

sly imp
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Let me phrase it this way: How could I calculate the number of possibilities where only 2 girls are standing next to each other in this situation?

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Since that's what I'm trying to subtract from the total number of possibilities

wary fiber
sly imp
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Yeah

wary fiber
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4320 possible combinations occur when 3 girls and 5 boys are arranged in a row such that all 3 girls are always together

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however in your question it says 4 boys not 5

sly imp
vocal sleetBOT
#

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desert flax
#

I am stuck on number two I don’t know how to find the variables after finding the equations

twin meteorBOT
desert flax
#

<@&286206848099549185>

idle pasture
#

Hello hello

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Hm

desert flax
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Hello

idle pasture
#

One sec

desert flax
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Ok ok

idle pasture
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Alr so the each Sold amount of t Shirts and hoddies IS X

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X IS a variable for an unknown number

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I got 95 t Shirts and 94 Hoodies Not completly Sure If thats true

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Bassically did (5680 / 20€) - 189

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Which Is 95

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And how i calculated the hoddies should be clear

vocal sleetBOT
#

@desert flax Has your question been resolved?

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raw flax
#

Hello

vocal sleetBOT
raw flax
#

I need help with integrals

vast shale
#

dm me

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digital sedge
vocal sleetBOT
digital sedge
#

i need help with these type of equations

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ik u do 0=x-0.15x^2

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but idk what to do after that

pliant lintel
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For part B we can use the information given in the picture that the arc of rosies path is a parabola with a vertex x value that can be found by using the vertex formula -b/2a

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ring a bell?

digital sedge
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yes ik that part

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i just cant do a

pliant lintel
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For part a, we know that the points of interest are the points at where rosie is touching the ground

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therefore, when h(x)=0

digital sedge
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yes

pliant lintel
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So if you set h(x)=0 and solve for x, that will give you 2 points where rosie is on the ground

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so you know those values are for where she first jumps, and where she lands

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where she lands is your distance

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setting h(x)=0 you get x-0.15x^2 = 0

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you may factor that and set each factor to 0

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youll get one factor that states x=0, thats the value where rosie started, but the other value you get is where she landed (the distance)

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This works because h(x) is equal to 0 when the object is at ground level

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and since we know that the only time rosie is at ground level is when she jumps and when she lands, those are the 2 values youre looking for

digital sedge
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yes so x-0.15x^2=0

pliant lintel
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correct

digital sedge
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and x1 will be 0

pliant lintel
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right

digital sedge
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but idk how to do the equation

pliant lintel
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so we have x-0.15x^2=0

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we see we can factor an x out of the left side

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giving us x(1-0.15x)=0 right?

digital sedge
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yes

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ohh

pliant lintel
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So you see, one of the values of x would be 0 which is where rosie started on the ground

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setting the other factor to 0 would give you the other point she was on the ground which has to be where she landed

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so what do you get when you do that

digital sedge
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is x2

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(1-0.15x)=0

pliant lintel
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Thats right

digital sedge
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and 0.15x=1

pliant lintel
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right

digital sedge
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then 1/0.15

pliant lintel
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Exactly

digital sedge
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= 6.7

pliant lintel
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rounded to the nearest 10th yes

digital sedge
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yeah its like 6.666666

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and if i do b

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i want middle of the jump

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so 6.7/2?

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h(3.35)= 3.35 -0.15*3.35^2 ?

pliant lintel
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Close, but that wont give you the exact answer because youre plugging in a rounded value

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usually you want to plug in an exact value

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so it would be 6.66666/2 and then you plug in h(3.333)

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you can also do this by recognizing that the given equation is a parabola, and knowing that the x value of the vertex of a parabola is -b/2a

So from here you can just see that b=1 and a=-0.15

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So you can calculate -1/(2*-0.15) and get your x value that way

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then plug that x value in for the equation

digital sedge
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i got 1.7

pliant lintel
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Rounded to the nearest 10th that should be right

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remember to include your units

digital sedge
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can we do another similar one rq

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this one

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a is 40

pliant lintel
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Correct, we use the same method in the last one to solve for b

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We see that the width is given by where the parabola touches the x axis

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and we know that at the x axis, x=0

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So we know that h(x) is going to be 0 at these 2 points, the start and the end

digital sedge
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0=-0.0023x^2+40

pliant lintel
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Right, we see that we cant factor an x out there so what do you think we should do

digital sedge
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factor something other than x maybe

pliant lintel
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You could but that wouldnt get you both values of x

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Since we cant immediately factor an x out here to get both roots, we must do it a different way

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We could isolate x instead by getting the 40 to the other side

digital sedge
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so -0.0023x^2=40 ?

pliant lintel
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=-40*

digital sedge
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oh yeah

pliant lintel
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Then from there we can further simplify to isolate x by multiplying both sides by -1 to get rid of the negatives

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so we get 0.0023x^2 =40

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Then to further isolate x we just divide both sides by 0.0023

digital sedge
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x^2= 17391 ?

pliant lintel
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Yes, but depending on how specific you need your answer, you need to not approximate until you get to the final answer

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x^2 ~ 17391

digital sedge
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17391.30435

pliant lintel
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That is still an approximation but closer to the values we want

digital sedge
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thats as far the calculator we use went

pliant lintel
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What must we do do get both values of x here

digital sedge
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sqrt17391.30435

pliant lintel
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right, you square root both sides

digital sedge
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then x = plus minus

pliant lintel
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Careful though because you must take the positive and negative square root

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Yeah

digital sedge
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plus minus 131.88

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then the bridge would be 131.88 *2

pliant lintel
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Exactly

digital sedge
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~264

pliant lintel
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Correct, however since you approximated the square root, your value is rounded to the nearest whole number

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Rounded to the nearest 100th, the answer would be 263.76 but depending on what your instructor wants, your answer might be fine

digital sedge
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yeah cheat sheet says 264

pliant lintel
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just make sure in the future, to not approximate values until the final answer

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if they want you to round to the nearest 10th or 100th, rounding values before your final answer will skew your final answer

digital sedge
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yeah

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if i get -wtvx= -wtvy

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can i times it with -1 and get both positive

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like we did before

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na nvm

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thanks

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ur good at explaining

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latent magnet
#

Can you take the laplace transform of the unit step function alone? The definition usually is L{f(t-a)u(t-a)} = e^-as F(s) where F(s) = L{f(t)} but in the ode I'm trying to solve the right hand side is just 1 - u(t-2) and idk how to take the laplace transfrom of that

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latent magnet
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<@&286206848099549185>

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latent magnet
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<@&286206848099549185>

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vernal isle
#

An aircraft weighing 238,000 Newtons drives at 40 degrees to the horizontal with a speed of 21.5 meters per second. Compare the load factor at this instant with the load factor at the lowest point in the pull-out. Calculate also the aerodynamic lift at both instances. The radius of turn is assumed to be constant at 12.2 meters.

vernal isle
#

what is load factor

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#

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unique glade
vocal sleetBOT
unique glade
#

Trying to find value of Tan(22.5degrees)

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I did it twice and I keep getting the same answer, but on the website it says the answer is

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Squareroot 2, - 1

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I get squareroot 2, -2

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unique glade
vocal sleetBOT
unique glade
#

Answer is what I have, but the 1/2 is negative

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What did I do wrong?

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Trying to find sin 9pi/8

outer warren
#

in the half angle identities,
there is a +- for the root
here it doesn't say that both signs are valid, but that you should determine the appropriate sign based on the angle

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i.e you should identify what quadrant 9pi/8 is in
and whether sin is positive or negative in that quadrant

unique glade
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idk if im losing my mind

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but i keep getting it to quadrant 1

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pi/4 9 times

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gets me back to quadrant 1

outer warren
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you want the location of the original angle for the final sign

unique glade
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9pi/8

outer warren
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yes, what quad is that in

unique glade
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quadrant 3 i think

outer warren
#

yes

unique glade
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ok thanks g

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that was confusing for some reason lol

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fading spruce
#

Hi, i need some help on a proof. I wanna show, that the following matrix is positive definite.

fading spruce
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this is in essence the statement i have been trying to proof. Idk if there is an easier way

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this is where im stuck

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<@&286206848099549185>

vocal sleetBOT
#

@fading spruce Has your question been resolved?

vocal sleetBOT
#

@fading spruce Has your question been resolved?

fading spruce
#

<@&286206848099549185>

thin vale
fading spruce
#

yes

thin vale
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the dimension is arbitrary?

fading spruce
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were supposed to check which dimensions work

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n=1 is trivial

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n=2 too

thin vale
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is there a cap on n?

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or you're checking for all natural numbers

fading spruce
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it cant be infinity

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but any arbitrary natural number is allowed

fading spruce
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at least not in a way i could think of

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btw technically im supposed to check for every n wether A represents an inner product

thin vale
#

have you shown all but positive definiteness

fading spruce
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A is obviously symmetric, and im pretty sure its positive definite aswell, but i have no idea how to proof that

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yes

thin vale
#

have you tried showing that <Ax, x> >=0

fading spruce
fading spruce
thin vale
thin vale
fading spruce
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A is positive definite then x^T A x > 0

thin vale
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yes

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and what did you compute x^T A x to be

thin vale
fading spruce
thin vale
fading spruce
thin vale
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are any of the x_i negative

fading spruce
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in order for this to be 0, the absolute value of the second term must be smaller than the first term

fading spruce
thin vale
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ah

fading spruce
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i played around with the x_i's a bit but i could proof the inequality

thin vale
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maybe rewrite the second sum to be to n

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and subtract off the nth term

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so that way you can combine the sums

fading spruce
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already did that

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i dont see how that helps tho

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because intuitively, this inequality must be true, i just cant get to the point of actually proving it and it annoys me

thin vale
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you have to take the absolute value

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of the x_i x_i+1 sum

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then you want to show the difference is > 0

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and then you can use the triangle inequality

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the absolute value of the sum will be less than the sum of the absolute values

#

then you can combine them as you did above, or perhaps differently as I recommended (not sure if either way is better)

#

but you could reindex the second sum instead of the first

fading spruce
#

everything you just explained i already did

thin vale
#

Okay, I'm just spitballing ideas and in the last pic you sent I don't see that stuff

#

sorry it hasn't worked

fading spruce
#

1 sec

#

im not criticizing you, im just very frustrated with that problem

thin vale
#

Maybe my friend will know

thin vale
fading spruce
#

yeah but there are no cancelling terms

red bear
#

what is happening

fading spruce
red bear
#

uh yes this looks right

thin vale
red bear
#

because of rearrangement inequality

#

can prove with cauchy schwarz i believe

fading spruce
#

cauchy schwarz only works if thats already an inner product no?

red bear
#

actually something more is true, any $\sum^n_{i=1}x_i^2 \ge \sum^n_{i=1}x_ix_{\sigma(i)}$ for any permutation $\sigma$ of ${1,2\dots,n}$

twin meteorBOT
red bear
twin meteorBOT
fading spruce
#

the xi's are not vektors

#

theyre real numbers

red bear
#

yeah...

#

im talking about the vector $(x_1,\dots,x_n)$

twin meteorBOT
fading spruce
#

oh thats what you meant

#

i dont think were allowed to use cauchy schwarz

red bear
#

bruh why not

fading spruce
#

we have to follow our script and the cauchy schwarz inequality comes after that ex

red bear
#

well im not sure how to help you then

fading spruce
red bear
#

can you first prove cauchy schwarz?

#

it's very easy

fading spruce
#

well technically i could

#

if thats the only way to do the ex i think its okay

fading spruce
red bear
#

im not sure if its the only way, but i think it is by far the easiest and cleanest and i wouldn't really want to think of a different way

red bear
fading spruce
#

okay wait let me write it down

#

just based on this

#

i wouldnt know how to get from this to the inequality that i want to show

red bear
#

ok so the left hand side is the square of the sum you want minus one of the terms right

fading spruce
#

the inequality is flipped

red bear
#

both terms in the right hand side are the same, since the vectors have the same magnitude

#

so you just square root both sides

#

and you are done

fading spruce
#

maybe im just being stupid but that doesnt make sense to me

red bear
#

what are you confused about

fading spruce
#

oh wait

red bear
#

just plug in both vectors, and do some algebra and you will see

fading spruce
#

i just misread

#

you were talking about the x vector and permutation vector

red bear
#

when

fading spruce
#

this

red bear
#

right

fading spruce
#

sorry, im very tired but that makes sense now

#

thanks

red bear
#

Cool

red bear
#

So if I have 5 apples 3 bananas and 1 orange, and I want to assign prices to maximize profit, I should 3 dollars to apples, 2 dollars to bananas and 1 dollar to oranges

fading spruce
#

the problem wasnt that i didnt know it had to be true, i just didnt see a way to proof it but the cauchy schwarz inequality makes it very easy to proof yeah

#

i visualized it with 2 squares

#

but i didnt see the trick

red bear
#

@thin vale doubt clarified

thin vale
red bear
thin vale
red bear
#

astronaut floating in space: wait it's all cauchy schwarz?
astronaut behind him with gun: always has been

fading spruce
#

i didnt look at anything later on in the script because usually youre supposed to use the stuff that you already know

#

but i was kinda helpless

thin vale
#

cauchy schwarz is so intuitive you're supposed to know it since birth

red bear
#

you can multiply both sides by two

#

and then move everything over to one side

#

and factor everything into squares

fading spruce
#

omg

#

i think thats how were supposed to do it

#

i just tralized that thats possible

#

thats way easier lol

#

i cant believe i didnt see that

#

im crying

red bear
#

I think this and the Cauchy shwarz are about the same level of difficulty though

fading spruce
#

i just crossed out the factor of 2 because i didnt think it would be important

red bear
#

,rotate

twin meteorBOT
fading spruce
#

but that way you can just neatly factor everything

#

into squares

red bear
#

well you need an extra x_1x_n term, but it only helps you

fading spruce
#

yeah but i shouldve seen that earlier

#

.close

vocal sleetBOT
#
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inner patrol
#

Hi, I have this stats question. So, I am wondering about question 3b and 3c. I'm confused on the difference. My approach to 3b was follows:
Take $\mathbb{P}(|\bar{Y} - \mu| \le 0.5) = \mathbb{P}(-0.5 \le \bar{Y} - \mu \le 0.5$. and then by dividing both sides by $\sigma / \sqrt{n}$, we get the standard normal cdf. So, we get $2\Phi (\frac{-0.5}{\sigma / \sqrt{n}}) = 0.1$ by saying that n is large enough for it to approximate a normal distribution. thus, we want $\Phi (\frac{-0.5}{\sigma / \sqrt{n}}) = 0.05$ by plugging qnorm(0.05) into R, I get that $\frac{-0.5}{\sigma / \sqrt{n}} = -1.64485$. And then solving for n gives the approximation.

inner patrol
#

hold on a sec

twin meteorBOT
#

theaveragejoe6029

inner patrol
#

wouldn't it be the exact same answer since in b we say n is bigger enought that we assume it to be a normal distribution and c we assume its a normal distribution

#

also sorry for my bad latex above

vocal sleetBOT
#

@inner patrol Has your question been resolved?

vocal sleetBOT
#

@inner patrol Has your question been resolved?

inner patrol
#

Sorry to do this, but <@&286206848099549185>

vocal sleetBOT
#

@inner patrol Has your question been resolved?

vocal sleetBOT
#

@inner patrol Has your question been resolved?

#
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edgy ginkgo
#

hey
for this exercise I am asked to write down the first 3 terms of the Maclaurin series of the functions given to me
Then I am asked to find for which values of x does the Maclaurin series of that function absolutely converges
Here's what I've done

edgy ginkgo
#

made a mistake
where I write Radius of convergence I meant Interval of convergence

#

the thing I'm mostly unsure of is when I have two separate series that describe a function, is the overall interval of absolute convergence their intersection?

(for example I found that for the first series the Interval of convergence is from -♾️ to ♾️ whereas in the second series I found that the Interval of convergence is from -1 to 1. Will the final interval of convergence be their intersection aka -1 to 1?)

vocal sleetBOT
#

@edgy ginkgo Has your question been resolved?

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#

@edgy ginkgo Has your question been resolved?

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#
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stark grail
vocal sleetBOT
stark grail
#

Question 8 pls

uneven belfry
#

ahem who is @flint topaz

#

what does it say in the first part

flint topaz
#

What is the value of theta

vocal sleetBOT
#

@stark grail Has your question been resolved?

stark grail
#

No

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stark lagoon
#

Working through some past paper questions on integrals, theyre just mcq but I struggle with some, mainly u substitution struggles me a bit

stark lagoon
#

1, 2, 3 are easy enough

#

4 ive got a bit done but got stuck

#

and the rest im lost

robust python
scenic ravine
#

for 5 use Integration by parts

robust python
#

doing the from (something) to (something) is easy enough u just find top minus bottom

stark lagoon
vocal sleetBOT
#

@stark lagoon Has your question been resolved?

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nova pecan
#

Choose polynomials whose degrees are equal

vocal sleetBOT
nova pecan
#

help

outer warren
#

do you know the definition of "degree" in the context of polynomials

outer warren
#

look for the term with the highest power on the variable
that power will be the degree

robust python
#

Also if theres mutliple variables

#

u gotta add the degrees of each variable

#

on every term

robust python
#

basically what they just said

outer warren
#

there isn't much more detail for single variable polynomials

#

unless you don't know the definition of power

nova pecan
#

what should I do in such a situation?

outer warren
#

exactly as i described

robust python
# nova pecan tell me more in detail

What's the degree of k? Well k=k^1, so 1
What's the degree of 3k^4? 4
What's the degree of -2k^2? 2
What's the degree of 5? There's no variable, so 0
So you take the biggest
meaning ur degree is 4 for the top left

#

try doing that for every polynomial on there

#

until u find the same degree for 2

nova pecan
#

is that right answer?

outer warren
#

no

#

go through the powers term by term

#

what is the power of m in:
3m^2
3m^4
5m^7
7m^3

outer warren
#

yes

vocal sleetBOT
#

@nova pecan Has your question been resolved?

#
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#
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gray monolith
#

Hello
I just found this question online and when I tried to solve it I get a result different than the answers provided
The question is " what is the ratio of the colored area to the uncoloured area)

gray monolith
#

And By the way
This question assumes that pi is equal to 22/7

sharp frost
gray monolith
#

You can also use the rombo area formula for the uncoloured area and you would still get 2r²

winter thistle
sharp frost
#

Is the answer c ?

winter thistle
winter thistle
sharp frost
#

Area of uncoloured is 2r^2

gray monolith
#

This is what I have done

sharp frost
#

Now area of coloured

gray monolith
sharp frost
#

,rotate

twin meteorBOT
winter thistle
#

why 2 pi r^2?

gray monolith
winter thistle
gray monolith
winter thistle
#

yup

gray monolith
#

Thank you @winter thistle @sharp frost
Sometimes I make stupid mistakes ( a lot of times😭)

winter thistle
gray monolith
#

.close

vocal sleetBOT
#
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vocal sleetBOT
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quartz beacon
#

Does anyone know what the number 19 means here? When you calculate binomial distributions in this app geogebra it will generate a number for your distribution, but I was curious as to what it meant

robust python
#

forgive??

#

oh

cyan talon
#

variable / distribution idk

robust python
#

distribution

quartz beacon
#

Distribution

cyan talon
#

it's just the number of steps I think

grim lotus
#

is it just be or is the distribution wrong

cyan talon
#

the doc just says "returns a bar graph"

grim lotus
#

shouldn't the max be at 10

grim lotus
#

oh maybe it's adding all probabilities

cyan talon
#

sum of probabilities = 19 sure

grim lotus
#

kind of a dumb thing to return cuz it's just 20-1 and 20 is ur input

quartz beacon
grim lotus
cyan talon
#

yeah it's the cumulative distribution that's plotted

quartz beacon
#

Im just curious because the number looks random at sight

#

But surely there’s some reasoning

cyan talon
#

I literally cited the documentation of geogebra

#

that's why I think it's just a number of bars or some dumb stuff like that

#

just change the n a bit, we'll see

quartz beacon
#

This is for 60

autumn stratus
#

what are you trying to do?

#

because this command is missing an argument

grim lotus
#

personally i don't like geogebra

quartz beacon
#

huh

cyan talon
autumn stratus
quartz beacon
#

Yeah

grim lotus
quartz beacon
#

451

grim lotus
#

maybe we should plot all values and do regression KEK

cyan talon
#

hehe

autumn stratus
#

it might be the expected value

#

nvm

grim lotus
#

i think it's just a number where the probability is close to 1

autumn stratus
#

if you increase p what happens

#

say 0.9

quartz beacon
#

what n do u want

cyan talon
#

if you remove the true and just look at the pdf, the return is 1

grim lotus
#

so ur saying it's the sum of the sum?

#

like sum the value at each point

cyan talon
#

it's the sum of the cdf

#

which is kinda dumb

grim lotus
#

yea

#

opencry why would that be useful

quartz beacon
#

wait what is it haha

grim lotus
#

u sum the cumulative probabilities

#

like sum P(X <= i) for i = 1 to n

quartz beacon
#

oh

grim lotus
#

wait that's just n - expectation

cyan talon
#

but for n=10 the output is 10 tho

#

wtf

grim lotus
#

what's p

#

maybe it's n - np = n*(1 - p)

autumn stratus
quartz beacon
#

Isnt it still right for n=10

#

If you just count it up

quartz beacon
cyan talon
#

n(1-p) + 1 it seems

#

yea

quartz beacon
#

So n(1-p)+1 yes

#

What does that mean tho

grim lotus
#

good question

cyan talon
#

well prolly the area under the bar graph

quartz beacon
#

kinda the estimated value for failure + 1?

cyan talon
#

+1 cause they included the last point for some reason

quartz beacon
#

This is hurting my brain

#

Hm

cyan talon
#

what have we become

quartz beacon
#

because estimated value for binomial distribution is n*p

cyan talon
#

yea sure

quartz beacon
#

But then the one wouldn’t make sense

#

It all doesn’t make sense to me tbf

cyan talon
#

we're not the geogebra devs

#

don't ask us really

quartz beacon
#

I wish

grim lotus
#

this is why i don't like geogebra

quartz beacon
#

my teacher didn’t know so I got curious

cyan talon
#

fking docs

quartz beacon
#

😭

#

we have to use geogebra

#

Ok thanks tho

#

.close

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#
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vocal sleetBOT
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forest lichen
#

How do i find the surface area of a shape like this?
(i already know what the base is, and the height is 6.)

grand rune
#

Multiply cross sectional are of base by the height

haughty arrow
haughty arrow
grand rune
forest lichen
forest lichen
#

thank you very much thanks

#

.close

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#
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vast shale
#

can i square root the whole 8k^2-k^4=16

#

just a simple yes or no

winter thistle
#

no

vocal sleetBOT
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west plaza
#

How do I determine the second differential to this general solution?

west plaza
#

I can't take the derivative of it twice

#

the differential should be sin(x)y'' - cos(x)y' = 0 but i have no idea how to get there

strange crater
#

why can't you take the derivative twice?

vocal sleetBOT
#

@west plaza Has your question been resolved?

west plaza
#

if you do that and you plug it into the differential, you get -C2sin(x) + C1 = ?

west plaza
west plaza
#

y' = -C2sin(x)

#

y'' = -C2cos(x)

#

y'' + y' + y = ? the right hand side cant be 0 because of C1

#

then just plug the values in it

#

idk

winter thistle
#

well you shouldn't just plug it into y'' + y' + y, the general form of a second order differential is something like f(x)y'' + g(x)y' + h(x)y = 0, and if you plugged in y'', y' and y into the left hand side, and compare coefficients of C1 and C2, you should be able to find what f, g and h are

#

although, I've never seen a question asking what the 2nd order differential of a general soln is before, so I'm not 100% sure

vocal sleetBOT
#

Please show the original problem, exactly as it was stated to you, with the entire original context. A picture or screenshot is best. If the original problem is not in English, then post it anyway! The additional context might still be helpful. Do your best to provide a translation.

dusk vale
#

?

vocal sleetBOT
#

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#
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tropic juniper
#

you can have it you're the goat anyway

vocal sleetBOT
tropic juniper
#

.close

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orchid lodge
#

hi

vocal sleetBOT
orchid lodge
#

A bend in a road is formed from two concentric arcs with inside radius 𝑟 and
outside radius 𝑅, each of a third of a circle with the same centre. The road is
then formed of tangents to the arcs.
A cyclist cuts the corner by following an arc of radius 𝑥 which is tangent to
the outside of the road at its ends and tangent to the inside of the road in the
middle.
Prove that 𝑟 + 𝑥 = 𝑘 𝑅 for some number 𝑘 to be found.

#

can someone explaint his?

vocal sleetBOT
#

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upper warren
#

😳

vocal sleetBOT
upper warren
#

.close

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frozen viper
#

helpo

vocal sleetBOT
frozen viper
#

basic problem but I'm slumped lmao

heavy yoke
#

use trigonometry

crude arrow
#

say we draw a equilateral triangle

#

of side length 2x

#

then we put a perpendicular bisector

frozen viper
#

perpendicular bisector is what

crude arrow
frozen viper
#

I sent it already

crude arrow
#

no

#

draw a equilateral triangle
of side length 2x

#

@frozen viper

frozen viper
#

yeah

#

so just 10 x 60

crude arrow
#

what

#

draw the triangle man

frozen viper
#

10 | x | 60 degree

crude arrow
#

mathematics is about DOING

#

it's not a spectator sport

frozen viper
#

fuck mathematics I want the answer

#

lol

crude arrow
#

language man

frozen viper
#

how do I get the answer with no paper

dapper jay
dapper jay
#

sin, cos, or tan?

frozen viper
#

tan

dapper jay
#

ok

twin meteorBOT
#

cwatson

dapper jay
#

in the image

frozen viper
#

opposite over adjacent

glacial osprey
#

look im all for trig but why dont we just use special right triangles

frozen viper
#

you guys could literally have just said 5tan(60)

glacial osprey
#

The point is that you learn how to do the problem so that you dont need to ask again

frozen viper
#

I learned that I could just do that

glacial osprey
#

Well good job then

#

🏅

vocal sleetBOT
#

@frozen viper Has your question been resolved?

vocal sleetBOT
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crude arrow
vocal sleetBOT
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daring marsh
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How do I solve this?

vocal sleetBOT
sharp frost
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Do you know 5^3?

daring marsh
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yeah

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125

sharp frost
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So

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125^1/3?

daring marsh
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5

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ah I see now

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thanks man

sharp frost
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Nice

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What did u get @daring marsh

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Ans

daring marsh
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1/625

sharp frost
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Yep

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That's right

daring marsh
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cool

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.close

vocal sleetBOT
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vocal sleetBOT
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Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
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cedar linden
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still cant solve this

vocal sleetBOT
cedar linden
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\begin{align*}
\int_{1}^{2}  \frac{x}{(x - 2) (x - 4)} & = \left[ x = (x - 4)A + (x-2)B \right] \\
&4 = (2)B \quad \Rightarrow \quad B = 2 \\
&2 = -2A \quad \Rightarrow \quad A = -1 \\
&= \int_{1}^{2} \frac{-1}{x - 2} + \int_{1}^{2} \frac{2}{x - 4} \\
&= - \ln|x - 2|  + 2 \ln|x - 4| + c      
\end{align*}```
twin meteorBOT
silk osprey
cedar linden
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not everyone are as smart as you 😦

silk osprey
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try this

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instead of the limit being 2

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let it be some number b

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and take the limit

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as b -> 2

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but use b instead of 2 in your anti derivative

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so evaluate i from 1 to b

silk osprey
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so you have 2ln(x-4)-ln(x-2)

cedar linden
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\begin{align*}
\int_{1}^{2}  \frac{x}{(x - 2) (x - 4)} & = \left[ x = (x - 4)A + (x-2)B \right] \\
&4 = (2)B \quad \Rightarrow \quad B = 2 \\
&2 = -2A \quad \Rightarrow \quad A = -1 \\
&= \int_{1}^{2} \frac{-1}{x - 2} + \int_{1}^{2} \frac{2}{x - 4} \\
&= - \ln|x - 2|  + 2 \ln|x - 4| \Bigg|_{1}^{B}  
\end{align*}```
twin meteorBOT
cedar linden
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you meant this

silk osprey
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yea sure

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yea

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but not

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the same B

cedar linden
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so i dont need to conver them into infinity

silk osprey
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you used in partial fraction

cedar linden
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can you correct my latex?

sharp frost
cedar linden
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so knief say instead of look for the B, just use the variable itself

silk osprey
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yea and take the limit as b->2

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same thing but might be easier to understand

sharp frost
silk osprey
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can you rewrite the -ln(x-2)+2ln(x-4)

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in terms of one log

cedar linden
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to multiply

silk osprey
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it makes it easier to plug in the limits

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how would you rewrite it

sharp frost
silk osprey
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yup

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i’m aware

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we did this problem earlier

silk osprey
cedar linden
twin meteorBOT
silk osprey
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yes

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now plug in the limits

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and lmk what you get

cedar linden
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i think

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im just idiot

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$= \lim_{b \to 2} , \ln | \frac{(x - 4)^2}{x - 2} |$

twin meteorBOT
cedar linden
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this is all i have

silk osprey
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ok and what about the lower limit

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like the 1

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should be that -ln(9)

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it doesn’t matter obviously but

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yea

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@cedar linden

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so did you try to evaluate that limit

cedar linden
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i tried to solve that fraction to see if i could eliminate the x - 2 but i couldnt

sharp frost
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It doesn't bring a indeterminate form

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Like 0/0 or infty/infty

cedar linden
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well

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i think i wont be able to solve this hahaha

silk osprey
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and the limit as x->2 for (x-2)^2

cedar linden
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for x - 2 is 0
and for the other one is 0 too

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if im not in the same thing then just tell me

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and i will close this

silk osprey
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well

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(2-4)^2 is 4 yes

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and 2-2 is 0

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so

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you have

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ln(4/0)

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but hmm

cedar linden
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yeah

silk osprey
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you can’t divide by zero right

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but

cedar linden
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yes

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but

silk osprey
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does that ring any bells

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division by zero

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with a nonzero numerator

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what happens

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when you divide by zero or take the limit and the denominator approaches zero

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what happens to the quotient

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if it helps

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think of what happens if you took 1/0.0000000000001

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if you divided by a reallllly small number

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what would happen to the quotient

cedar linden
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wont be indeterminate

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mmm

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you are telling me to do something

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like

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let B equal to 2.0000000001

silk osprey
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really like B=1.999999999 but yes

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because we’re coming from the left

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the interval is 1 to 2

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so we’re on the left side of 2

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but it doesn’t matter

cedar linden
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okay okay

silk osprey
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well think of the graph of 1/x

cedar linden
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so we can say
let b be equal to 1.99999999

silk osprey
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what is the lim x->0

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of 1/x

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,w graph 1/x

silk osprey
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lets just look at it from one side

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either one

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as x goes to zero

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what does 1/x go to

cedar linden
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to 0.01

silk osprey
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how’d you get that

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don’t look at the numbers on the axes

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just look at the behavior

cedar linden
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ah to positive infinite_

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?

silk osprey
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yes

cedar linden
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okay okay

silk osprey
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think about it if i did 1/0.00000001 that’s really like multiplying 1000000000

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so as it gets smaller and smaller

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the quotient blows up

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to infinity

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does this make sense

cedar linden
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yes

silk osprey
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so

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you have ln(2/0)

cedar linden
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because from 1 to 0 there are infinite numbers

silk osprey
cedar linden
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to positive infinite too

silk osprey
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yes

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because lim x->2 of (2/(x-2)) goes to infinity

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so

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ln(infinity)

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is infinity

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this make sense?

cedar linden
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sure

silk osprey
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no like fr

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you understand that?

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2/(x-2) was just the inside

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of the ln

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because we had ((x-4)^2/(x-2))

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and i just simplified the numerator to 2

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because x->2

cedar linden
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sure we evaluated to limits so we got positive infinite
so we say ln (infinite) and thats equal to infinte

silk osprey
cedar linden
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yes

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\begin{align*}
\int_{1}^{2}  \frac{x}{(x - 2) (x - 4)} & = \left[ x = (x - 4)A + (x-2)B \right] \\
&4 = (2)B \quad \Rightarrow \quad B = 2 \\
&2 = -2A \quad \Rightarrow \quad A = -1 \\
&= \int_{1}^{2} \frac{-1}{x - 2} + \int_{1}^{2} \frac{2}{x - 4} \\
&= - \ln|x - 2|  + 2 \ln|x - 4| + C \\
&= \ln | \frac{(x - 4)^2}{x - 2}| \\
&= \lim_{b \to 2} \, \ln | \frac{(x - 4)^2}{x - 2} | = +\infty \\
&= +\infty - \ln | (\frac{25}{-3}) | \\
&= + \infty + \ln | \frac{25}{3} | + C        
\end{align*}
#

@silk osprey

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whats your opinion

heavy yoke
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remove the $$

twin meteorBOT
cedar linden
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now?:D

silk osprey
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if its infinite then there’s no need to add the constant terms

cedar linden
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,w \int_{1}^{2} \frac{x}{(x - 2) (x - 4)}

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aight

silk osprey
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and if you plugged in 1 you’d get ln(9)

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it’s really infinity-ln(9) but that’s just infinity

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and for a definite integral there is no +C

cedar linden
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yeahh

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im stupid

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ahaha

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the nervious

silk osprey
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no worries

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just state it’s divergent

cedar linden
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but my answer is correct?

silk osprey
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without the ln(25/3) and +C

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then yea

cedar linden
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what i do with the ln 25/3?

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i did it because i evalute 1

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what

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wiat

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i didt wrong

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i just realilzed

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xD

silk osprey
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yup

cedar linden
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JAJAJAJ

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yeah

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i did with -1

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idk why nervious

silk osprey
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no worries

cedar linden
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so it will be

  • infinite + ln(9)
silk osprey
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doesn’t matter because it’s infinite

silk osprey
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infinity plus any number is stil infinity

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so you can just write infinity

cedar linden
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vaaaaaa

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vava

silk osprey
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infinity isn’t a number

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you don’t add numbers to infinity

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it’s just infinity

cedar linden
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hey

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htanks

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probably my teacher wrote that integral wrong

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because we are not working with limits or ln | 0 |

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but it was fun