Is this double integral set up correctly?

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SUMMARY

The discussion centers on setting up a double integral to find the volume enclosed by the cylinder defined by the equation x² + y² = 1, the plane x = 0, and the plane z = y. The correct integral setup is identified as ∫^1_{-1} ∫^{√(1-x²)}_0 y dy dx, which integrates over the area above the x-axis. However, it is concluded that the combination of these geometric entities does not enclose a finite volume, as the cylinder is infinite and the planes do not create a bounded region.

PREREQUISITES
  • Understanding of double integrals in calculus
  • Familiarity with cylindrical coordinates
  • Knowledge of geometric shapes defined by equations (e.g., cylinders and planes)
  • Basic principles of volume calculation in three-dimensional space
NEXT STEPS
  • Study the properties of infinite cylinders and their intersections with planes
  • Learn about setting up double integrals for volume calculations
  • Explore the implications of integrating over unbounded regions
  • Investigate the use of z = 0 as a bounding plane for finite volume calculations
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Students and professionals in mathematics, particularly those studying calculus and geometry, as well as educators looking to clarify concepts related to volume calculations involving cylindrical shapes.

G01
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1.Set up the integral to Find the volume enclosed by the cylinder x^2 +y^2 = 1 x=0 and z=y


3. The area to integrate over is the part of x^2 + y^2 =1 above the x axis. X goes from -1 to 1 and y goes from 0 to sqrt(1-x^2) So the integral should be:

[tex]\int^1_{-1} \int^{\sqrt(1-x^2)}_0 y dy dx[/tex]

 
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The way you phrased the question, I don't think that the volume is above the x-axis (or the x-plane). The x=0 plane is the yz plane, so it is actually cutting your cylinder in-half vertically and the the z=y plane is slashing your cylinder diagonally.
 
G01 said:
1.Set up the integral to Find the volume enclosed by the cylinder x^2 +y^2 = 1 x=0 and z=y


3. The area to integrate over is the part of x^2 + y^2 =1 above the x axis. X goes from -1 to 1 and y goes from 0 to sqrt(1-x^2) So the integral should be:

[tex]\int^1_{-1} \int^{\sqrt(1-x^2)}_0 y dy dx[/tex]

Please go back and recheck the statement of the problem. x2+ y2[/suo] is an infinite cylinder and x= 0 is a plane crossing the x-axis. Together they bound an infinite "half-cylinder". z= y is a plane that crossing that half-cylinder. The three together do NOT bound a region of finite volume. The region either above or below z= y does not have finite volume. If the second equation were z= 0, then it would make sense.
 

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