MATLAB: Finding the minimum value of a function and corresponding x_min

minimum of a function and corresponding x_min

now after running this code we got plot like parabola by figure anyone can find what is the minimum value of phi1 and at which x it is minimum can any one suggest me how to find the minimum phi1 and what is x_min by code not by figure.so far i am using this code but by this i get incorrect value of x_min that's why i also get wrong min_phi1,x_min should be L/2 and this can be verified by the plot code is attached with question

Best Answer

doc min.
[val,idx] = min(phi1) ; % get minimum value of phi1 and it's index
x_min = x(idx) % x at which phi1 is minimum
phi1_min = val % minimum phi1