- #1

jrg_pz

- 1

- 0

x=e^tsint,

and y=e^tcost where (t) is greater than or equal to (0) and (t) is less

or equal to pi divided by (2).

when it is revolved about

a) the x-axis

b) the y-axis (approximation with calc. (how?))

You are using an out of date browser. It may not display this or other websites correctly.

You should upgrade or use an alternative browser.

You should upgrade or use an alternative browser.

- Thread starter jrg_pz
- Start date

- #1

jrg_pz

- 1

- 0

x=e^tsint,

and y=e^tcost where (t) is greater than or equal to (0) and (t) is less

or equal to pi divided by (2).

when it is revolved about

a) the x-axis

b) the y-axis (approximation with calc. (how?))

- #2

amcavoy

- 665

- 0

jrg_pz said:

x=e^tsint,

and y=e^tcost where (t) is greater than or equal to (0) and (t) is less

or equal to pi divided by (2).

when it is revolved about

a) the x-axis

b) the y-axis (approximation with calc. (how?))

Around the x-axis you have:

[tex]\text{SA}_x=2\pi\int_{a}^{b}f(x)\left(\sqrt{1+f'(x)^2}\right)dx[/tex]

...the y-axis you have:

[tex]\text{SA}_y=2\pi\int_{a}^{b}x\left(\sqrt{1+f'(x)^2}\right)dx[/tex]

And I assume you can figure out what f(x) and dx are in terms of your parametric equations...

Share:

- Replies
- 10

- Views
- 325

- Replies
- 6

- Views
- 472

- Last Post

- Replies
- 1

- Views
- 449

- Last Post

- Replies
- 1

- Views
- 324

- Replies
- 2

- Views
- 192

- Replies
- 9

- Views
- 576

- Replies
- 9

- Views
- 471

- Last Post

- Replies
- 13

- Views
- 762

- Last Post

- Replies
- 4

- Views
- 840

- Last Post

- Replies
- 2

- Views
- 206