In Cartesian coordinates the vector operators for gradient, divergence, rotational and Laplacian are of the form
∇ϕ = grad ϕ = i ∂ϕ/∂x + j ∂ϕ/∂y + k ∂ϕ/∂z.
∇ ⋅ V = div V = ∂V_x/∂x + ∂V_y/∂y + ∂V_z/∂z.
∇ × V = curl V = i(∂V_z/∂y - ∂V_y/∂z) + j(∂V_x/∂z - ∂V_z/∂x) + k(∂V_y/∂x - ∂V_x/∂y).
∇²ϕ = ∇ ⋅ ∇ϕ = div grad ϕ = ∂/∂x ∂ϕ/∂x + ∂/∂y ∂ϕ/∂y + ∂/∂z ∂ϕ/∂z = ∂²ϕ/∂x² + ∂²ϕ/∂y² + ∂²ϕ/∂z² (the Laplacian).
determine the expressions for each operator in coordinates
a) Cylindrical
b) Spherical