kak tolong bantu yang nomer 1 yaa

Tan x = a = a/1 = depan/samping
miring = √(a² + 1²) = √(a² + 1)
Sin x = depan / miring = a/√(a² + 1)
Cos x = samping/miring = 1/√(a² + 1)

Sin 2x = 2 sin x cos x
= 2 . a/√(a² + 1) . 1/√(a² + 1)
= 2a/(a² + 1)