code for check wether the given differential function is function g(x) or g(x,y) in matlab

how to check wether the given differential function is function g(x) or g(x,y) in matlab

maybe i am doing mistake

clear

clc

syms x y

a=input('f(x,y)=')

f=inline(a,'x','y')

g=inline(diff(f(x,y),x))

if g==f(x)

k=g(1)

elseif g==f(x,y)

k=(1,2)

end

Answer 1

[John D'Errico]

Easy. For example...

syms x y
expr1 = 2*x;
expr2 = x + x*y;

Now use symvar.

symvar(expr1)

ans = 

x

numel(symvar(expr1))

ans = 1

symvar(expr2)

ans = 

numel(symvar(expr2))

ans = 2

So expr2 is a function of two symbolic variables.