Declination of Sun

`delta_("Sun") = arcsin[sin( -"obliq"_"(Earth)") * cos(360^o /"Yr"_"tropical" *(N+10) + 360^o/pi * "Ecc"_"(Earth)" * sin(360^o/"Yr"_"tropical" (N-2)) ) ]`

`"Number of Days into the Year"`