Find the volume of the region below the graph of f (x, y) = 16 − x2 − y2 and above thexy-plane in the first octant. Hint: convert to polar coordinates
Question
Find the volume of the region below the graph of and above the xy-plane in the first octant.
Hint: Convert to polar coordinates.
Solution
To find the volume of the region below the graph of f(x, y) = 16 - x² - y² and above the xy-plane in the first octant, we can use a triple integral in polar coordinates. Here are the steps:
-
Convert the function to polar coordinates: f(r, θ) = 16 - r², where r² = x² + y².
-
Set up the limits of integration. Since we're only considering the first octant, 0 ≤ θ ≤ π/2, 0 ≤ r ≤ 4 (since r² = x² + y² ≤ 16), and 0 ≤ z ≤ 16 - r².
-
Set up the triple integral: ∫ from 0 to π/2 ∫ from 0 to 4 ∫ from 0 to 16 - r² r dz dr dθ. The extra factor of r is due to the Jacobian determinant when converting from Cartesian to polar coordinates.
-
Evaluate the innermost integral: ∫ from 0 to π/2 ∫ from 0 to 4 [rz] from 0 to 16 - r² dr dθ = ∫ from 0 to π/2 ∫ from 0 to 4 r(16 - r²) dr dθ.
-
Evaluate the middle integral: ∫ from 0 to π/2 [4r² - r⁴/4] from 0 to 4 dθ = ∫ from 0 to π/2 (64 - 64) dθ = 0.
-
Evaluate the outermost integral: [0] from 0 to π/2 = 0.
So, the volume of the region below the graph and above the xy-plane in the first octant is 0.
Similar Questions
Evaluate the integral of f (x, y) = x over the region given by 4 ≤ x2 + y2 ≤ 16. Hint: convertto polar coordinates.Page 2 of 2
Find the volume of the given solid.Bounded by the cylinders x2 + y2 = 16r2, y2 + z2 = 16r2
Use a graphing utility to graph the polar equations. Find the area of the given region analytically.common interior of r = 8 sin(2𝜃) and r = 4
Determine the volume of the solid obtained by rotating the region bounded by𝑦 = 𝑥2 − 4x + 5, x = 1, x = 4 and the x-axis about the x-axis. (78𝜋5
Find the volume of the pyramid bounded by the plane x + 2y + 6z = 12 in the first octant(x ≥ 0, y ≥ 0, z ≥ 0)
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.