How to use the factorial function in Matlab

Hi everybody, I have a problem with Factorial function.

I wrote:

syms x
f= factorial(x)
....

(I want to calculate the limit of some function...)

Immediately, Matlab annouce: "??? Error using ==> factorial at 17 N must be a matrix of non-negative integers."

How can I fix this error? I want to calcualate the limit of y=f(x)=9^x/(x!)

Thanks.

Answer 1

[Walter Roberson]

Try

f = sym('x!');