jika tan x = 2 dengan A terletak di kuadran III, maka hitunglah nilai dari sin (180-x) -sin(90-x) cos (90 +x) +cos(180-x)

tan x = 2

depan = -2
samping = -1
miring = √5

sin x = -2√5/5
cos x = -√5/5

= {sin(180 - x) - sin(90 - x)} / {cos(90 + x) + cos(180 - x)}
= (sin x - cos x) / -cos x - cos x
= -√5/5 / √5/5
= -1