What the meant of the symbols # and & on the following example

[Chris]

Bellow is presented an eigenvalue resultant of a jacobian matrix... where appears (..)#1 and (..)#1^2,& what it means?

Root[C0 CG^2 vG^2 vL \+(2 C0 CL^2 vG vL \[Alpha]^2 \[Rho]L^2+C0 CL^2 vL^2 \[Alpha]^2 \[Rho]L^2) #1+([Alpha] \[Rho]L^2-C0 CL^2 vG \[Alpha]^2 \[Rho]L^2-2 C0 CL^2 vL \[Alpha]^2 \[Rho]L^2) #1^2&,1]

best regards

[svke...@aol.com]

This is what Mathematica calls a pure function. The # represents a variable. #1 is one variable, #2 would be another. In your result, #1 is one new variable Mathematic added. #1^2 is that variable squared. The & is just a sign that the preceding is a pure function.

For example, you could write a function lixe this:

f[x]:= x^2

or you could write it as a pure function:

f=#^2&

Either way, f[3] would give you an answer of 9, and f[x+y] would return (x+y)^2.