how to correct (( ??? Undefined function or method 'FindZeros' for input arguments of type 'function_handle'. ))

??? Undefined function or method 'FindZeros' for input arguments of type 'function_handle'.

Rt = FindZeros(Ex4, 5, linspace(0,10*pi,100), []);

This is my codes>>

%Problem: 5.4

Ex4 = @(x) (sin(x)-x.*cos(x)) Rt = FindZeros(Ex4, 5, linspace(0,10*pi,100), [])

%Problem: 5.5

Ex5 = @(x,p) (2*cos(x)-(x/p-p./x).*sin(x)); p = [0.1 1]; for k = 1:2 Rt = FindZeros(Ex5, 5, linspace(0,10*pi,100), p(k))' end

[Star Strider]

Please post the code for ‘FindZeros’. It’s not in the File Exchange and the only other reference I can find is in Solve Equations Numerically.