Question

Найдите f штрих (x) если f(x)=2x+1/x-3

Answer 1

$\displaystyle f`(x)=( \frac{2x+1}{x-3})`= \frac{(2x+1)`(x-3)-(x-3)`(2x+1)}{(x-3)^2}=\\\\= \frac{2(x-3)-(2x+1)}{(x-3)^2}= \frac{2x-6-2x-1}{(x-3)^2}= \frac{-7}{(x-3)^2}$