Write out the Picard iteration scheme. If possible, find the solution.
$x'=cos(x),x(0)=0$
I did the picard iterations but I don't know how to get the solution from this
$$u_0=0,...,u_3=\int_0^t\cos(\sin(s))ds$$
I know the solution is this
The solution to the IVP is $x(t)=2\tan^{-1}(\tanh(\frac t2))$