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Exercise 1918Calculus › Multivariable calculus › Vector calculusM1Added 3 Nov 2026

Conservative fields in 3D

#conservative#3D#potential

Statement

Show that F⃗=(yz,xz,xy)\vec F=(yz,xz,xy) is conservative and find a potential.

Hint

∇×F⃗=0\nabla\times\vec F=0; find ϕ\phi with ∇ϕ=F⃗\nabla\phi=\vec F.

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Solution

Curl. ∇×F⃗=0\nabla\times\vec F=0 (computed earlier), so F⃗\vec F is conservative on R3\mathbb{R}^3.

Potential. Integrate yzyz in xx: ϕ=xyz+g(y,z)\phi=xyz+g(y,z). Then ∂yϕ=xz+gy=xz\partial_y\phi=xz+g_y=xz, so gy=0g_y=0; similarly gz=0g_z=0.

Result. ϕ=xyz\phi=xyz.

Conclusion. F⃗=∇(xyz)\vec F=\nabla(xyz).