Tthe tutorial section of DifferentialEquations.jl on Boundary Value Problems states that: " The third argument of `BVProblem`

is the initial guess of the solution, which is constant in this example."

In this example the constant guess is u(t)=pi/2 and u’(t)=pi/2 for all t from the time interval. How can I make a nonconstant guess such as u(t)=sin(t) & u’(t)=cos(t)?