What is the second derivative of #1/(1+x^2)#? Calculus Basic Differentiation Rules Quotient Rule 1 Answer Andrea S. Dec 12, 2016 #d^((2))/(dx^2) (1/(1+x^2)) = frac (6x^2-2) ((1+x^2)^3)# Explanation: #f(x) = 1/(1+x^2)# Based on the chain rule: #f'(x) = d/(dx) (1+x^2)^(-1) =(2x)(-1)(1+x^2)^(-2) = (-2x)/((1+x^2)^2)# Using the quotient rule: #f''(x) = frac ((-2)(1+x^2)^2 +2x*2x *2(1+x^2)) ((1+x^2)^4) = frac ((-2)(1+x^2) +8x^2) ((1+x^2)^3)= frac (6x^2-2) ((1+x^2)^3)# Answer link Related questions What is the Quotient Rule for derivatives? How do I use the quotient rule to find the derivative? How do you prove the quotient rule? How do you use the quotient rule to differentiate #y=(2x^4-3x)/(4x-1)#? How do you use the quotient rule to differentiate #y=cos(x)/ln(x)#? How do you use the quotient rule to find the derivative of #y=tan(x)# ? How do you use the quotient rule to find the derivative of #y=x/(x^2+1)# ? How do you use the quotient rule to find the derivative of #y=(e^x+1)/(e^x-1)# ? How do you use the quotient rule to find the derivative of #y=(x-sqrt(x))/(x^(1/3))# ? How do you use the quotient rule to find the derivative of #y=x/(3+e^x)# ? See all questions in Quotient Rule Impact of this question 19342 views around the world You can reuse this answer Creative Commons License