Question

Jika cos 1/2x = 0,2 maka tan x=?

Answer 1

Cos 1/2 x = 0,2 = 2/10 = 1/5
cos x = 2(cos 1/2 x)^2 - 1
cos x = 2(1/5)^2 - 1
cos x = 2/25 - 1 = -23/25 = sa/mi ... kuadran 2
de = √(25^2 - 23^2) = √(625 - 529) = √96 = 4√6
tan x = de/sa = - 4√6 / 23