How can I plot two functions in the same graph?

I have a code like this:

fplot(@(x) cosh(x))

hold on

p(x) = 0.6671x^3-1.7921x^2+2.7580x-0.089

fplot(@(x) p(x))

hold off

since p(x) is a more complex function. And when I try to run the code, the command shows "Invalid expression. Check for missing multiplication operator, missing or unbalanced delimiters,

or other syntax error. To construct matrices, use brackets instead of parentheses."

I don't know how to fix for this. Please me, thank you!

Answer 1

[Torsten]

fplot(@cosh)
hold on
p = @(x)0.6671*x.^3-1.7921*x.^2+2.7580*x-0.089;
fplot(p)
hold off

Answer 2

[Jim Riggs]

Try this:

fplot(@(x) cosh(x));
hold on
fplot(@(x) 0.6671x^3-1.7921x^2+2.7580x-0.089);