Jawabanmu

2014-06-05T15:36:19+07:00
(1+sin x)/(1-sin x) x (1+sin x)/(1+sin x)
= 1 + 2sin x + sin² x / 1 - sin²x
= 1 + 2sin x + sin²x / cos²x
= (1/cos²x) + (2sin x/cos²x) + (sin²x / cos²x)
= sec²x + ( 2sin x/cos x)/cos x + (tan²x)
= sec² x + 2tan x sec x + tan²x
= (sec x + tan x)² (terbukti)