Differentiation: find f' for f(x) = 2x/1+x^2

[startingover]

f(x) = 2x/1+x^2

f'(x) = (1+x^2)(2) - (2x)(1-x^2)(2x)/(x+1^2)^2

f'(x) = [2(1+x^2)] - [4x^2]/(1+x^2)

f'(x) = 2+2x^2-4x^2/(1+x^2)

f'(x) = 2-2x^2/1+x^2

f'(x) = 2(1-x^2)/1+x^2

 

[galactus]

Don't forget to square your denominator.