Math Problem Statement

Solve this question of Multivariable Calculus (Integration) till the end and give the final solution

Find the volume of the ellipsoid given by \( \frac{x^2}{a^2} + \frac{y^2}{b^2} + \frac{z^2}{c^2} = 1 \).

Solution

To solve the given problem, we need to compute the volume of the ellipsoid given by:

x2a2+y2b2+z2c2=1\frac{x^2}{a^2} + \frac{y^2}{b^2} + \frac{z^2}{c^2} = 1

Step 1: Volume formula for an ellipsoid

The volume of an ellipsoid is calculated using a standard formula derived from multivariable calculus:

V=43πabcV = \frac{4}{3} \pi a b c

Where aa, bb, and cc are the semi-axes of the ellipsoid.


Step 2: Integration Derivation (Optional Explanation)

To derive this, we use a change of variables that scales the ellipsoid into a unit sphere: Let: u=xa,v=yb,w=zc.u = \frac{x}{a}, \quad v = \frac{y}{b}, \quad w = \frac{z}{c}. Under this transformation, the ellipsoid becomes the sphere: u2+v2+w2=1.u^2 + v^2 + w^2 = 1.

The Jacobian determinant for this transformation is abcabc, so the volume of the ellipsoid is scaled by this factor relative to the volume of the unit sphere.

The volume of the unit sphere is 43π\frac{4}{3} \pi. Multiplying by the scaling factor abcabc gives: V=abc43π=43πabc.V = abc \cdot \frac{4}{3} \pi = \frac{4}{3} \pi a b c.


Step 3: Final Answer

The volume of the ellipsoid is:

V=43πabcV = \frac{4}{3} \pi a b c


Would you like further clarification or details on how this formula was derived? Let me know!


Related Questions:

  1. How is the Jacobian determinant used in multivariable calculus to change variables?
  2. Why does the unit sphere have a volume of 43π\frac{4}{3} \pi?
  3. Can you calculate the surface area of an ellipsoid?
  4. What happens if a=b=ca = b = c? How does the ellipsoid become a sphere?
  5. How would the volume change if one axis of the ellipsoid approaches zero?

Tip:

For ellipsoids with symmetry along axes, always verify the semi-axes lengths (aa, bb, and cc) before applying the formula!

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Math Problem Analysis

Mathematical Concepts

Multivariable Calculus
Integration
Ellipsoid Volume

Formulas

Volume of an ellipsoid: \( V = \frac{4}{3} \pi a b c \)

Theorems

Use of Jacobian determinant in variable transformations

Suitable Grade Level

Undergraduate level (Multivariable Calculus)