Question

help please

help please

2c

http://prnt.sc/chmhxa

Answer 1

@agent0smith

Answer 2

this is what i graphed

http://prnt.sc/chn2qv

Answer 3

What is your question, sister?

Answer 4

idk how to solve it lol

Answer 5

Because the axis is y=-1, if you draw the radius for either, you should notice that the radius is 1 unit longer, than it would be if the x-axis was the axis of rotation.

So just add 1 to each of the inner and outer radius, washers should be easy.

Answer 6

hmm so then what would this be ?

washer or disk ?

Answer 7

You still haven't learned that they're basically the same thing ;P a washer is just a disk with a hole in it.

There's two radii right? You drew them in pink. A disk can't have two radii...

Answer 8

true so then its washer ? lool
aaahhhh i get em confuse idk whyyy

Answer 9

A disk has an outer radius.

A washer has an outer and inner radius.

Answer 10

HOW do you get em confused still x'd

Answer 11

If you shade in that area, then imagine rotating around y=-1, it's not gonna be a solid object, right? Finna look like a donut.

Answer 12

yeh .. draw it for me neega x'd

Answer 13

If you imagine rotating it, and it'll make a solid object with no holes, then it's a disk.

I can't draw it in 3D. Shade in the enclosed region between the two functions, and use your brain... imagine rotating it ;P

Answer 14

But memorize this:

A disk only has an outer radius.

A washer has both an outer and inner radius.

Answer 15

And they literally are the SAME thing gurl. They use the same formula. Washer and disk both use:\[\Large V = \pi \int\limits_{a}^{b} \text{Outer}^2 - \text{Inner}^2 \]If there is no inner radius at all, then inner radius is just zero.

Erase disk method from your brain. Use washer method. That's what i do.

A disk is just a washer, with no inner radius.

Answer 16

loooll ooo x'd

Answer 17

I've been trying to get you to realize this for weeks x'd they're the same damn thing! There should never be confusion!

Answer 18

Washer and cylindrical shells are different formulas.

Answer 19

yaas x'd

Answer 20

You got dis?

Answer 21

yesh lool u gona help me with some more ;p