Question

производная
f(x)=4 ln (x-1)/(x+1) ; x=-3

Answer 1

f`(x)=4(x+1)/(x-1)*(x+1-x+1)/(x+1)²=4(x+1)/(x-1)*2/(x+1)²=8/[(x-1)(x+1)]=8/(x²-1)
f`(-3)=8/(9-1)=8/8=1

Answer 2

$y'=4* frac{x+1}{x-1} * frac{x+1-x+1}{(x+1)^2} = frac{4}{x-1} * frac{2}{x+1} = frac{8}{x^2-1} \ y'(-3)=frac{8}{(-3)^2-1}= frac{8}{8}=1$