Найти D (f) если f(x) =корень из -5/х^2 +3х - х-1/х+1
Advantages: 1. You can study longer than others, who wants to sleep 2. You can read a lot of books 3. You don't waste your time to sleeping disadvantages: 1. You always feel tired 2. It can badly affect on your health 3. You will have a patient view