Displaying a more precise answer when using diff()

Hi guys, I'm doing this in MATLAB

syms x

f = (cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(x)))))))))))))))));

c = sym('1');

diff(c)

And it gives me ans = 0. But I know the answer is not 0. How can I get a more exact answer? Specifically the answer to this derivative is 0.00178818.

Thank you!

Answer 1

[Roger Stafford]

In your code you have asked for the derivative of the constant 1, and of course its derivative will be zero. You need to find the expression for the derivative of f with respect to x and only then evaluate it for x = 1. That is, do diff(f,x) first, then find its numerical value at x = 1.

[Ramses Sanchez]

Awesome! Thank you.