Respuesta :
Answer:
V = ∫∫∫rdrdθdz integrating from z = 2 to z = 4, r = 0 to √(16 - z²) and θ = 0 to 2π
Step-by-step explanation:
Since we have the radius of the sphere R = 4, we have R² = r² + z² where r = radius of cylinder in z-plane and z = height² of cylinder.
So, r = √(R² - z²)
r = √(4² - z²)
r = √(16 - z²)
Since the region is above the plane z = 2, we integrate z from z = 2 to z = R = 4
Our volume integral in cylindrical coordinates is thus
V = ∫∫∫rdrdθdz integrating from z = 2 to z = 4, r = 0 to √(16 - z²) and θ = 0 to 2π
Answer:
[tex]\displaystyle V = \int\limits^{2 \pi}_{0} \int\limits^{2\sqrt{3}}_{0} \int\limits^{\sqrt{16 - r^2}}_2 {r} \, dz \, dr \, d\theta[/tex]
General Formulas and Concepts:
Multivariable Calculus
Cylindrical Coordinate Conversions:
- [tex]\displaystyle x = r \cos \theta[/tex]
- [tex]\displaystyle y = r \sin \theta[/tex]
- [tex]\displaystyle z = z[/tex]
- [tex]\displaystyle r^2 = x^2 + y^2[/tex]
- [tex]\displaystyle \tan \theta = \frac{y}{x}[/tex]
Volume Formula [Cylindrical Coordinates]:
[tex]\displaystyle V = \iiint_T \, dV \rightarrow V = \iiint_T {r} \, dz \, dr \, d\theta[/tex]
Step-by-step explanation:
Step 1: Define
Identify given.
Solid sphere w/ radius 4 centered at (0, 0, 0) → x² + y² + z² = 4²
Plane z = 2
Step 2: Find Volume Pt. 1
Find bounds of z.
- [Sphere] Substitute in plane z:
[tex]\displaystyle x^2 + y^2 + 2^2 = 4^2[/tex] - Substitute in cylindrical conversions:
[tex]\displaystyle (r \cos \theta)^2 + (r \sin \theta)^2 + 2^2 = 4^2[/tex] - Simplify:
[tex]\displaystyle r^2 + 4 = 16[/tex] - Solve for r:
[tex]\displaystyle r = 2\sqrt{3}[/tex]
∴ 0 ≤ r ≤ 2√3
Step 2: Find Volume Pt. 2
- [Sphere] Substitute in plane z:
[tex]\displaystyle x^2 + y^2 + 4 = 16[/tex] - Isolate variables:
[tex]\displaystyle x^2 + y^2 = 12[/tex] - [Unit Circle] Graph [See 2nd Attachment]
∴ 0 ≤ θ ≤ 2π
Step 3: Find Volume Pt. 3
- [Sphere] Substitute in cylindrical conversions:
[tex]\displaystyle (r \cos \theta)^2 + (r \sin \theta)^2 + z^2 = 4^2[/tex] - Simplify:
[tex]\displaystyle r^2 + z^2 = 4^2[/tex] - Solve for z:
[tex]\displaystyle z = \sqrt{16 - r^2}[/tex]
∴ 2 ≤ z ≤ √(16 - r²)
Step 4: Find Volume Pt. 4
- Substitute in variables [Volume Formula - Cylindrical Coordinates]:
[tex]\displaystyle V = \int\limits^{2 \pi}_{0} \int\limits^{2\sqrt{3}}_{0} \int\limits^{\sqrt{16 - r^2}}_2 {r} \, dz \, dr \, d\theta[/tex]
∴ the volume of the region is found with the integral above.
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Learn more about multivariable calculus: https://brainly.com/question/17203772
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Topic: Multivariable Calculus
Unit: Triple Integral Applications
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