Problem:
Find the curl of the vector field $f(x,y,z)\uvec{i} + g(x,y,z)\uvec{j} + h(x,y,z)\uvec{k}$ where $f(x,y,z) = \cos \left(x y^3\right)$, $g(x,y,z) = -\sin \left(x-y^3\right)$, and $h(x,y,z) = \tan \left(\frac{x}{y^3}\right)$
from sympy import *
from sympy.vector import *

C = CoordSys3D('C')
x, y, z = C.x, C.y, C.z
f = cos(x*y**3)
g = -sin(x-y**3)
h = -sin(x-y**3)
print(curl(f * C.i + g * C.j + h * C.k))

