Question about calculating area and volume

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    Area Volume
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Homework Help Overview

The discussion revolves around calculating the area and volume related to the function y = x^3, specifically in the context of rotation around the y-axis and the area between two curves. Participants are exploring the definitions and implications of these calculations in a two-dimensional versus three-dimensional context.

Discussion Character

  • Conceptual clarification, Problem interpretation

Approaches and Questions Raised

  • Participants are attempting to differentiate between the volume of a solid of revolution and the area between two curves. Questions are raised about the nature of the area being calculated and whether it can be considered a surface area.

Discussion Status

The discussion is ongoing, with some participants providing clarifications about the nature of the area in question, emphasizing that it pertains to the xy-plane rather than a three-dimensional surface. There is an acknowledgment of the need to understand the importance of calculating area, though some express uncertainty about its relevance.

Contextual Notes

Participants are navigating the definitions of area and volume within the constraints of their homework, questioning assumptions about dimensionality and the implications of their calculations.

Miike012
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When calculating the volume of say y = x^3 rotated around the y-axis from -2<=x<=2 I am the calculating a space occupied by a 3D figure... but when I am calculating the area between say y = x^3 and y=(-x)^3 from 0<= y <=8 what exactly is this area? is it surface area?
 
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It's the sum of the areas of all those whisker-thin rectangles, each of height equal to the vertical distance between the curves, viz, x^3 - (-x)^3, and of horizontal width equal to dx or Δx. So it's an area on the x-y plane, a flat area. You could call it a surface area, if you wish, but then all areas could be considered surface areas. couldn't they?
 
Miike012 said:
When calculating the volume of say y = x^3 rotated around the y-axis from -2<=x<=2 I am the calculating a space occupied by a 3D figure... but when I am calculating the area between say y = x^3 and y=(-x)^3 from 0<= y <=8 what exactly is this area? is it surface area?
No, there is no "surface" are because this is not a three dimensional problem. It is simply area in the xy-plane.
 
I guess ill figure out the importance of calculating area later because right now I don't see it..
 

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