The D.E. is...
Taking into account that is...
... we can separate variables and integrate, so that we obtain...
I been working on this forever. I am stuck at the integration part.
the problem is:
cosysint dy/dt = sinycost
the answer is
Here is my attempt :
cosy/siny dy = cost/sint dt
arctany dy = arctant dt
then i integrate both side and get
some there i am stuck.. i dunno how to get the answer y=arcsin(c sint)