Question

Jika alpa sudut lancip dan sin 1/2 x = akar dari x-1 per 2x . Tentukan nilai tan alpha

Answer 1

Sin 1/2 x = √{(x-1)/(2x)} 
tan 1/2 x = √{(x-1)/(x+1)}

tan x = 2 tan 1/2 x / ( 1 - tan² 1/2 x )

tan x = 2 √{(x-1) /(x+1)}/ { 1 - (x-1)/(x+1)}
tan 2x = (x+1)√{(x-1)(x+1)}