Jawabanmu

Jawaban paling cerdas!
2014-05-06T18:41:22+07:00
D (tan x) = D (sin x / cos x) 

D (tan x) = (cos x D (sin x) - sin x D (cos x)) / cos^2 x 
^ = pangkat 
coz.. 
D {f(x) / g(x)} = (g(x) D f(x) - f(x) D g(x)) / g^2 x 

D (tan x) = (cos x . cos x + sin x . sin x) / cos^2 x 
coz.. 
D (sin x) = cos x 
D (cos x) = - sin x 
jadi tandanya berubah tuh dari "-" jadi "+" 

D (tan x) = 1/ cos^2 x 
coz.. 
sesuai pythagorean identities cos x . cos x + sin x . sin x = cos^2 x + sin^2 x = 1 

D (tan x) = sec^2 x