What is the derivative of arctan(x)/(1+x^2)?

1 Answer
Feb 27, 2017

d/dx(arctan(x)/(1+x^2))=(1-2xarctan(x))/(1+x^2)^2

Explanation:

The quotient rule states that the derivative of a function f(x)=g(x)/(h(x)) is:

f'(x)=(g'(x)h(x)-g(x)h'(x))/(h(x))^2

Here we see that:

  • g(x)=arctan(x)" "=>" "g'(x)=1/(1+x^2)
  • h(x)=1+x^2" "=>" "h'(x)=2x

Then:

d/dx(arctan(x)/(1+x^2))=((1/(1+x^2))(1+x^2)-arctan(x)(2x))/(1+x^2)^2

color(white)(d/dx(arctan(x)/(1+x^2)))=(1-2xarctan(x))/(1+x^2)^2