jika tan x = 3/4 untuk x sudut lancip maka cos x =

Tan x = 3/4 = depan/samping
miring = √(3^2 + 4^2) = √(9 + 16) = √25 = 5
cos x = samping/miring = 4/5

tan x = 3/4 = y/x
r² = y² + x²
r² = 3² + 4²
r² = 25
r = 5

↓
Sudut lancip, maka
cos x = x/r = 4/5