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Exercise 1791Calculus › Multivariable calculus › Multiple integralsL1Added 3 Nov 2026

Volume of a sphere by triple integral

#spherical coordinates#volume#sphere

Statement

Compute the volume of the ball BR={x2+y2+z2≤R2}B_R=\{x^2+y^2+z^2\le R^2\} using spherical coordinates.

Hint

x=rsin⁡φcos⁡θx=r\sin\varphi\cos\theta, y=rsin⁡φsin⁡θy=r\sin\varphi\sin\theta, z=rcos⁡φz=r\cos\varphi; Jacobian r2sin⁡φr^2\sin\varphi.

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Solution

Spherical. 0≤r≤R0\le r\le R, 0≤φ≤π0\le\varphi\le\pi, 0≤θ≤2π0\le\theta\le2\pi.

Jacobian. r2sin⁡φr^2\sin\varphi.

Compute.
V=∫02π∫0π∫0Rr2sin⁡φ dr dφ dθ=2π⋅2⋅R33=4πR33.V=\int_0^{2\pi}\int_0^\pi\int_0^R r^2\sin\varphi\,dr\,d\varphi\,d\theta=2\pi\cdot2\cdot\frac{R^3}{3}=\frac{4\pi R^3}{3}.

Conclusion. V=4πR33V=\frac{4\pi R^3}{3}.