Jawabanmu

2014-05-20T11:04:35+07:00
Sin² α + sin² α cos² α + cos^4 α
= (1 - cos² α)+ (1 - cos² α) cos² α + cos^4 α
= 1 - cos² α + cos² α - cos^4 α + cos^4 α
= 1 . terbukti