Area of a surface of revolution around the x-axis

In summary, there can be instances where the surface area of a revolution can be negative when distinguishing between the inside and outside of a surface. Depending on how the formula is set up, it may be necessary to alter it to get the desired result. The question of whether the surface area can be negative was also confirmed.
  • #1
Bachelier
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Can the Surface area of a revolution be NEGATIVE? I am calculating this in parametric equations?

finally I hope this is the right forum to ask this question.
 
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  • #2
Bachelier said:
Can the Surface area of a revolution be NEGATIVE? I am calculating this in parametric equations?

finally I hope this is the right forum to ask this question.

Yes.

It is quite common for negative areas to show up in some context when you distinguish the inside and the outside of a surface. Depending on how you set up the formulae, you may have a case like this. Depending on what you are trying to find, you may need to alter the formula.

Cheers -- sylas
 

FAQ: Area of a surface of revolution around the x-axis

What is the formula for finding the area of a surface of revolution around the x-axis?

The formula for finding the area of a surface of revolution around the x-axis is A=2π∫(x)(f(x))dx, where x is the variable of integration and f(x) is the function representing the curve.

Can this formula be used for any shape?

Yes, this formula can be used for any shape as long as the curve is rotated around the x-axis to create a solid shape.

How is this formula derived?

This formula is derived from the concept of calculus known as the "disk method", where the surface of revolution is divided into infinitely thin disks whose areas can be calculated using the formula for the area of a circle. The sum of all these areas gives us the total surface area of the shape.

What are the units of measurement for the surface area?

The units of measurement for the surface area will depend on the units used for the function representing the curve. For example, if the function is in meters, then the surface area will be in square meters.

Can this formula be extended to find the volume of a solid of revolution?

Yes, this formula can be extended to find the volume of a solid of revolution by simply integrating the function f(x) instead of multiplying it by x. The resulting formula would be V=π∫(f(x))^2dx.

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