### 5.52.2 Laplacian : laplacian

laplacian takes two arguments : an expression F of n real variables and a vector of these variable names.
laplacian returns the Laplacian ofF, that is the sum of all second partial derivatives, for example in dimension n=3:

∇2(F)= |
∂2 F
∂ x2
| + |
∂2 F
∂ y2
| + |
∂2 F
∂ z2

Example
Find the Laplacian of F(x,y,z)=2x2y−xz3.
Input :

laplacian(2*x`^`2*y-x*z`^`3,[x,y,z])

Output :

4*y+-6*x*z