Multiple fminbnd errors with a parametrized function

I am trying to use fminbnd for this function, where I was given parametrizations to plug in. It keeps giving me errors and I'm not sure what they mean. Any advice would be appreciated.

fun = exp(cos(t)) - sin((3^(1/2)*sin(t))/3);
t1 = 0;
t2 = 2*pi;
fminbnd(fun, t1, t2)

Error using fcnchk (line 107)
If FUN is a MATLAB object, it must have an feval method.

Error in fminbnd (line 198)
funfcn = fcnchk(funfcn,length(varargin));

Error in sevenbi (line 10)
fminbnd(fun, t1, t2)

Answer 1

[Torsten]

You are in the realm of numerical, not symbolic computations.

Here, functions are defined as handles:

fun = @(t) exp(cos(t)) - sin((3^(1/2)*sin(t))/3);

[Cassandra Meyer]

Ohhh yup I was trying the @ symbol but forgot to define t. Thanks!!

Answer 2

[Catalytic]

Here is a symbolic method, if that's what you wanted.

syms t f(t)
f(t) = exp(cos(t)) - sin((3^(1/2)*sin(t))/3);

vpasolve(diff(f,t)==0,[0,2*pi])

ans = 

6.0708220544184582393726949540477