Jawabanmu

2014-06-10T15:14:01+07:00
(2 cos x - sin x)(cos x + sin x) = 0
2 cos x - sin x = 0
sin x = 2 cos x

dan

cos x + sin x = 0
son x = - cos x

jadi tan x
tan x = 2 cos x/cos x = 2
dan
tan x = -cos x/cos x = -1

D