tolong jawab pakai caranya sec x = a , maka sin 2x = ..... ?

sec x = a
sec x = miring/samping = a/1
Depan = √(a^2 - 1^2) = √(a^2 - 1)
sin x = depan/miring = √(a^2 - 1) / a
cos x = samping/miring = 1/a

Sin 2x = 2 sin x cos x
= 2 . √(a^2 - 1)/a . 1/a
= 2√(a^2 - 1) / a^2