Evaluating a symbolic function

Question

I want to find cos(5). Why is this expression invalid:

syms x
f=sin(x)
disp(diff(f)(5))

The error is

Line:         


        

Answer 1

Y = cos(x) will simply provide the cosine value of x. Or all the x.

I think in your code: disp(diff(f(5))) should work.