Jawabanmu

2014-04-03T22:20:04+07:00
(secx−tanx)²
= (1/cosx − sinx/cosx)²
= (1−sinx)² / cos²x
= (1−sinx)² / (1−sin²x)
= (1−sinx)² / ((1−sinx)(1+sinx))
= (1−sinx) / (1+sinx)