13.2.2 Functional derivative
The function_diff
command finds the derivatives of functions (as opposed to expressions, see Section 8.2.1).
-
function_diff takes
f, a function.
- function_diff(f) returns the derivative f′ of f.
Examples
| f(x):=x^2+x*cos(x):;
function_diff(f) |
To define the function g as f′:
The function_diff instruction has the same effect as
using the expression derivative diff (see Section 13.2.1)
in conjunction with unapply (see Section 8.2.2).
For example:
| g:=unapply(diff(f(x),x),x):;
g(x) |
Remark.
In Maple mode (see Section 2.5.2), for compatibility,
D may be used in place of function_diff. For this
reason, it is impossible to assign a variable named D in
Maple mode (hence you cannot name a geometric object D).