Create function handles for both the cos function and for an anonymous function, and then convert them to character vectors.

fh = @cos;
c = func2str(fh)

c =

cos

fh = @(x,y)sqrt(x.^2+y.^2);
c = func2str(fh);

disp(['Anonymous function: ' c])

Anonymous function: @(x,y)sqrt(x.^2+y.^2)

Create a function that evaluates a function handle for a single input.

Create the following function in a file, evaluateHandle.m, in your working folder.

function evaluateHandle(fh,x)

y = fh(x);
str = func2str(fh);

disp('For input value: ')
disp(x)
disp(['The function ' str ' evaluates to:'])
disp(y)

end

Use a function handle to evaluate the sin function at pi/2.

fh = @sin;
x = pi/2;
evaluateHandle(fh,x)

For input value: 
    1.5708

The function sin evaluates to:
     1

Use a function handle to evaluate for the specified matrix, A.

fh = @(x) x.^2+7;
A = [1 2;0 1];
evaluateHandle(fh,A)

For input value: 
     1     2
     0     1

The function @(x)x.^2+7 evaluates to:
     8    11
     7     8