Not sure where to integrate

[tulip tangle]

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[lament seal]

i feek confused about the "through 360°" thing

[trail vessel]

You need to Subtracted these two volumes

[lament seal]

ohhh i get the 360° now after seeing this

[trail vessel]

360° just means taking a full revolution

[lament seal]

i was thinking 2-dimensionally when i read it, that's why i had to bring it up

[trail vessel]

Ohh

[lament seal]

I'm curious, where'd you get pi from?

[trail vessel]

Oh i think you don't know integration is also use for calculating volumes

[trail vessel]

I just integratedthe thin cylinders from -1 to 2

[lament seal]

I'm actually on that KA lesson rn lol

[trail vessel]

dy is the height

x is radius

Volume of cylinder: πx²dy

But integration is wrt y , so i just written the value of x in terms of y

As x = f(y)

[lament seal]

The only thing that I don't understand rn is the cylinder

[trail vessel]

Why?

Volume of cylinder is use to calculate volume of different shapes in 3d

[lament seal]

KA's teaching me squares and rectangles for some reason

[lament seal]

I think I'm not on that lesson yet

[trail vessel]

I tried to draw my best

See if you sum all the thin cylinders from bottom to top

You will ultimately get volume of this wierd looking object

[lament seal]

Wait, so... why are squares and rectangles being taught to me?

[trail vessel]

Can you show me?

[lament seal]

https://www.khanacademy.org/math/ap-calculus-bc/bc-applications-of-integration-new/bc-8-7/v/volume-with-cross-sections-perpendicular-to-y-axis

[lament seal]

I FINALLY VISUALLY GET IT

[trail vessel]

It's actually a different concept

It is volume by cross section

[trail vessel]

And this question is from volume by revolution

[lament seal]

No wonder I got confused by the 360°

[trail vessel]

Yea

[lament seal]

Well at least I understand everything now thanks to you

Math is just... so cool

[trail vessel]

😋yah

[lament seal]

I'm just curious as to how this can be applied in the real world

[trail vessel]

Almost every concept of Calculus have real life application

[lament seal]

I mean this part of calc specifically

Modeling maybe?

[trail vessel]

Are you studying double and triple integration??

[lament seal]

idk?? i'm just self-studying ap calc bc

[trail vessel]

Ap bc??

[lament seal]

yeah

[trail vessel]

I mean what is it?

[lament seal]

im not actually gonna take the test i just wanna learn lol

[trail vessel]

Full form

[lament seal]

calc 1 & 2 in high school

[trail vessel]

Oh

[lament seal]

my school doesnt offer APs so i just study them on my own

[trail vessel]

Do wanna study together with me?