Question

Найдите производную функции f(x)=(x^2-1)/(x^2+1)

Answer 1

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