Question

sin³x+cos³x/sin³x-cos³x , если tgx =2

Answer 1

(Sin³x/Cos³x + Cos³x/Cos³x) / ( Sin³x/Cos³x - Cos³x/Cos³x) =
= (tg³x + 1) / ( tg³x - 1) = (2³ + 1) / ( 2³ - 1) = 9/7 = (1)2/7