- #1
peripatein
- 880
- 0
Hi,
I have a question concerning solid of revolution.
The bowl-shaped volume formed by rotating the area circumscribed between y=bcosh(1) and y=bcosh(x/a) around the y-axis was given to us by the instructor as pi*b*int [x^2*d(cosh(x/a))] between 0 and a.
My question is why are the integration boundaries not -a and a, but 0 and a, OR, alternatively, why wasn't the final answer then multiplied by 2?
When the same area is rotated around the x-axis the integration boundaries are indeed -a and a. Why aren't the boundaries similar in both cases?
I have a question concerning solid of revolution.
The bowl-shaped volume formed by rotating the area circumscribed between y=bcosh(1) and y=bcosh(x/a) around the y-axis was given to us by the instructor as pi*b*int [x^2*d(cosh(x/a))] between 0 and a.
My question is why are the integration boundaries not -a and a, but 0 and a, OR, alternatively, why wasn't the final answer then multiplied by 2?
When the same area is rotated around the x-axis the integration boundaries are indeed -a and a. Why aren't the boundaries similar in both cases?