# Multiple fminbnd errors with a parametrized function

1 view (last 30 days)
Cassandra Meyer on 25 Mar 2022
Commented: Cassandra Meyer on 25 Mar 2022
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)

Torsten on 25 Mar 2022
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 on 25 Mar 2022
Ohhh yup I was trying the @ symbol but forgot to define t. Thanks!!

Catalytic on 25 Mar 2022
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

R2021b

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!