Inline function is not working properly

So I am trying to make a stem graph and the text book uses inline to create a function for discrete time function but I keep having errors using it. The function is i just want to know for either an alternative or why the inline function isnt working with my code. Snippet of code not working:

n = -10:10;
f = inline('e^(-n/5).*cos(pi*n/5).*(n>=0)','n');
stem(n,f(n),'k');

Answer 1

[Guillaume]

is exp(x) in matlab. There is no need for inline:

f = @(n) exp(-n/5) .* cos(pi*n/5) .* (n>=0);

assuming is n>=0.