Question

1. ln l tan x sec x + sec²x l : ln l sec x + tan x l = sec x
buktikan

Answer 1

Mungkin maksudnya = ln|sec(x)|, ya ?

tan(x)sec(x) + sec²(x) = sec(x) (tan(x) + sec(x))
so,
ln |tan(x)sec(x) + sec²(x)| : ln |sec(x)+tan(x)
= ln|sec(x)(tan(x)+sec(x))| : ln |sec(x)+tan(x)|
= ln|sec(x)| * ln|sec(x)+tan(x)| : ln |sec(x)+tan(x)|
= ln |sec(x)|