How to define a mathematical function in SymPy?
sympy.Function
is for undefined functions. Like if f = Function('f')
then f(x)
remains unevaluated in expressions.
If you want an actual function (like if you do f(1)
it evaluates x**2 + 1
at x=1
, you can use a Python function
def f(x): return x**2 + 1
Then f(Symbol('x'))
will give a symbolic x**2 + 1
and f(1)
will give 2
.
Or you can assign the expression to a variable
f = x**2 + 1
and use that. If you want to substitute x
for a value, use subs
, like
f.subs(x, 1)