Найдите производную 1/x^2+1

y = 1/(x^2 + 1) = (x^2 + 1)^(-1)y ' = - 1 * (x^2 + 1)^ (-2) * (x^2 + 1) ' == - (x^ 2 + 1)^( -2) * 2x = - 2x/ (x^2 + 1)^2