Question

f(x) =2x-7\
x+3 найдите f'(x), f'(-2).

Answer 1

f'(x)=((2х-7)'(х+3) - (2х-7)(х+3)' )/(х+3)^2=
(2(х+3)-(2х-7))/(х+3)^2=(2х+6-2х+7)/(х+3)^2=13/(х+3)^2
f'(-2)=13/(-2+3)^2=13/1^2=13/1=13