Problem:
Find the laplacian of the function $f(x,y,z)$ where $f(x,y,z) = \sin (x-y-z)$
from sympy.vector import *
from sympy import *

C = CoordSys3D('C')
x, y, z = C.x, C.y, C.z
f = sin(x-y-z)
print(laplacian(f))
