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Determine whether the following vector field is conservative on R

3
. If so, determine the potential function. F=⟨3y+4z,3x+z,4x+y⟩ Select the correct choice below and, if necessary, fill in the answer box to complete your choice. A. F is conservative on R
3
. The potential function is φ(x,y,z)=. (Use C as the arbitrary constant.) B. F is not conservative on R
3
.

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User Wbk
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1 Answer

2 votes

Explanation:

The vector field F is conservative on R^3 if and only if it satisfies the condition of being a curl-free vector field.

We can check if F is conservative by computing the curl of F.

curl(F) = (∂Q/∂y - ∂P/∂z)i + (∂R/∂z - ∂P/∂x)j + (∂P/∂y - ∂Q/∂x)k

where P = 3y + 4z, Q = 3x + z, and R = 4x + y.

After computing the partial derivatives, we get:

curl(F) = 0i + 0j + 0k

Since the curl of F is zero, we can conclude that F is conservative on R^3.

To find the potential function, we need to integrate each component of F with respect to its corresponding variable.

φ(x,y,z) = ∫Pdx = ∫(3y + 4z)dx = 3xy + 4xz + C1(y,z)

φ(x,y,z) = ∫Qdy = ∫(3x + z)dy = 3xy + yz + C2(x,z)

φ(x,y,z) = ∫Rdz = ∫(4x + y)dz = 4xz + yz + C3(x,y)

where C1(y,z), C2(x,z), and C3(x,y) are arbitrary functions of the variables not being integrated.

To find the potential function, we can equate the three expressions for φ and solve for the arbitrary constants.

3xy + 4xz + C1(y,z) = 3xy + yz + C2(x,z) = 4xz + yz + C3(x,y)

Solving for the arbitrary constants, we get:

C1(y,z) = yz + C

C2(x,z) = 4xz + C

C3(x,y) = 3xy + C

where C is an arbitrary constant.

Therefore, the potential function for F is:

φ(x,y,z) = 3xy + 4xz + yz + C

answered
User Muhammad Taqi
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8.5k points