#This limit pls

161 messages · Page 1 of 1 (latest)

glad vigil
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Thus limit

untold oak
glad vigil
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One is cubic

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The other is normal

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Like the 2

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Nothing

untold oak
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In that case, start by factoring x from everything here. Then both roots will be of the form (1 + const/x)^a.

glad vigil
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I got an indeterminate form

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0x infinite

untold oak
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So, remember how there's a nice series for (1 + x)^a for x -> 0?

glad vigil
untold oak
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Ah, although, just to clarify.

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Is that x^2 or x^3 under the first root?

glad vigil
untold oak
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If we factor x out from everything here, what do we get under the first root?

glad vigil
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Wait do u want me to like factor by x even outside the root?

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Like Xroot of 1/x+ 2/x^2?

untold oak
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But one of the roots just goes to 0.

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So, there isn't actually an indeterminate form.

glad vigil
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But infini x0 is indeterminate form

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@untold oak

untold oak
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Ah, wait...

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It's x. Sorry, didn't notice.

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In that case, notice how the first term grows like x^(2/3), but the second grows as x^(1/2).

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So, which grows faster?

glad vigil
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1/2?

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Oh no wait 2/3

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Since 2/3>1/2

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But even so how do i demonstrate it

untold oak
# glad vigil Since 2/3>1/2

In this case we can try factoring x^(2/3) from both, instead. The first root will approach 1, but what about the second root?

untold oak
glad vigil
glad vigil
untold oak
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Well, I don't see any other easy methods.

fossil hound
# glad vigil Thus limit

since its a difference of cubic roots, maybe you can multiply and divide by the factor so in the numerator it simply becomes x^2+1 -x +2

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like, how would you factorize a^3-b^3?

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mhm i dont think this will work cause its still indterminate at the numerator

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well i tried

fossil hound
glad vigil
fossil hound
glad vigil
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What if i actually just add -x and +x each side since the udneterminate is + ♾️- ♾️

glad vigil
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The method u will simplify cubic one isnt the same as root one

fossil hound
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u wrote a 3 on both sides

fossil hound
fossil hound
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so u can get some variables out of the square root and they will be the highest grade variable

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mmmmm

glad vigil
fossil hound
glad vigil
fossil hound
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you get like cubic root of (x^2+1)^2 -x+2

glad vigil
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The issue here

fossil hound
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mhm

glad vigil
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Is that u need a number to set the conjuagate of cubic root

fossil hound
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cant u just use the cubic root

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at the denominator you get an infinity + infinity so its fine

glad vigil
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Its like a^3-b^3/a^2 +ab+b^2

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This is rhe conjuagte

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Of a term

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Cub

fossil hound
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but you just told me they arent cubic roots

glad vigil
fossil hound
fossil hound
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the rest isnt important

glad vigil
fossil hound
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the result will probably be 0 or infinity

fossil hound
fossil hound
glad vigil
glad vigil
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Then u cant

fossil hound
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ok lerts to bacvk a bit

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how wouilòd u solve limit for x that tends to + infinity

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of (2x^2+1)/(3x^2+2)

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?

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@glad vigil u there=

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?

fossil hound
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@glad vigil died 😔

glad vigil
glad vigil
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U u siplify

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2\3

fossil hound
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same principle

fossil hound
glad vigil
fossil hound
glad vigil
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Functions have limits

fossil hound
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why can you “forget” about the x but not the x^2 ?

glad vigil
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Wdym wai

fossil hound
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do u want the answer

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?

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btw it’s useless to learn maths without understanding what you are doing

glad vigil
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Give me the methode and ill see if i understand it

fossil hound
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so the trick is to group the highest grade variable:
x^2(3 -x/x^2 - 2/x^2)

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note that something like 2/x^2 tends to 0 when x tends to infinity ♾️

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so in the parenthesis u basically only have the 3

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so u get x^2(3 -0 -0)

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so the result in this case is simply infinite

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when u have a fraction , you group the highest grade for the numerator and denominator

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then simplify

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the result is either 0, ♾️ if the variable on the top has a higher grade than the one on the bottom

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or a certain value if they have the same grade

glad vigil
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Can u do that in a piece of paper

fossil hound
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try to write what i said urself

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i have troubles too understanding this stuff when it’s written like this 🥲

glad vigil
fossil hound
fossil hound
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@glad vigil is it clear now?

glad vigil
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Its a polynome

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Why even do that

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U could just take the higher x/ higher x

fossil hound
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you are doing this acritically

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you just following rules you dont understand

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obviously when solving u can skip these passages, but this is the reason of why it works

wide heraldBOT
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@glad vigil

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glad vigil
wide heraldBOT
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@fossil hound @untold oak The user still needs help with this help request.

fossil hound
glad vigil
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Functions

fossil hound
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you just use it acritically

glad vigil
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Yea how do i understand it?

fossil hound
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the picture i sent

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is the explanation

glad vigil
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U got it as zero

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It didnt get to zro if i di ur methide

fossil hound
fossil hound
glad vigil
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U solved the limit and u got zero

fossil hound
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wait

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mb LOL

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result is 2/3

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i missed up