Trigonometry -LRB- mathematics -RRB- : How do I prove that -LSB- math -RSB- -LRB- 1 + \ sin -LRB- \ theta -RRB- -RRB- -LRB- 1 - \ sin -LRB- \ theta -RRB- -RRB- = \ cos ^ 2 -LRB- \ theta -RRB- -LSB- / math -RSB- ?
Trigonometry -LRB- mathematics -RRB- : Is it possible to find -LSB- math -RSB- \ sin -LRB- \ theta/3 -RRB- -LSB- / math -RSB- when you 're given -LSB- math -RSB- \ sin -LRB- \ theta -RRB- -LSB- / math -RSB- ?