asked 139k views
2 votes
Use polar coordinates to find the volume of the solid below the plane 2x+y+z=4 and above the disk x² +y² ≤1.

asked
User Tsilb
by
8.6k points

1 Answer

1 vote

Final answer:

To compute the volume of a solid under 2x+y+z=4 and above the disk x²+y² ≤1, we express x and y in polar coordinates and integrate the resulting function z over the specified domain.

Step-by-step explanation:

The question asks to find the volume of a solid defined by a specific plane and a disk using polar coordinates. The plane equation given is 2x+y+z=4, and the disk is restricted by x²+y² ≤1. To find this volume we can integrate the function that represents the height of the plane above the disk in polar coordinates. In polar coordinates, x=rcosθ and y=rsinθ, where r is the radius and θ is the angle. The plane's equation becomes 2rcosθ+rsinθ+z=4. Solving for z, we get z=4-2rcosθ-rsinθ. As the disk has a radius of 1, we integrate over r from 0 to 1 and θ from 0 to 2π to obtain the volume.

The integration setup is therefore:

∫∫^{2π}_{0}∫^{1}_{0} (4-2rcosθ-rsinθ) r dr dθ

To solve, we multiply the integrand by r (the Jacobian when converting to polar coordinates) and integrate with respect to r first, then θ. After calculating both integrals, the evaluated expressions will yield the volume of the solid.

answered
User Doseke
by
7.8k points
Welcome to Qamnty — a place to ask, share, and grow together. Join our community and get real answers from real people.