Volume of revolution about the x-axis generated between curves

Volume of revolution about the x-axis generated between curves

Volume of Revolution about the x-axis

  • The volume of revolution around the x-axis is the volume of the solid body that is obtained when you revolve a planar region around the x-axis.
  • This volume is typically found by using the method of integration.

The Theory of Volume of Revolution

  • The general formula for the volume formed by revolving a curve about the x-axis is given by V = π ∫[a, b] [y(x)]² dx.
  • This tells us that we need to integrate the square of the function, multiplied by π, over the given interval [a, b].
  • In this formula, a and b are the limits of the region along the x-axis, y(x) is the function defining the curve, and dx indicates that it’s an integral with respect to x.

How to Find the Volume of Revolution

  • First, set up the integral using the formula mentioned above. That is, identify the limits a and b, and the function y(x).
  • Next, compute the integral. This may require using specific integration techniques, like integration by parts, substitution, or partial fractions.
  • After performing the integration, multiply the result by π to get the volume.
  • Don’t forget to interpret the results in the context of the problem.

Points to Remember

  • The method of calculating the volume of revolution about the x-axis involves the use of calculus, and specifically the operation of integration.
  • Sometimes, finding the integral can be quite complex and may involve the use of more advanced integration techniques. It is, therefore, important to brush up your integration techniques.
  • It is also essential to know how to correctly set up the limits of integration. These limits will be the end points of the region in the x-axis being revolved. -Attention to detail: Make sure to square the function y(x) within the integral, as the formula calls for y(x)².
  • Consistently practise previous exercises to enhance understanding and speed in solving problems related to volumes of revolution.