Answer: The field F has a continuous partial derivative on R.
Step-by-step explanation:
For the field F has a continuous partial derivative on R, fxy must be equal to fyx and since our field F is āf,
āf = fxi + fyj + fzk.
Comparing the field F to āf since they at equal, P = fx, Q = fy and R = fz
Since P is fx therefore;
āP āy = ā āy( āf āx) = ā2f āyāx
Similarly,
Since Q is fy therefore;
āQ āx = ā āx( āf āy) = ā2f āxāy
Which shows that āP āy = āQ āx
The same is also true for the remaining conditions given