## Calculus: Early Transcendentals 8th Edition

$y'=\frac{2x}{1+x^4}$
Use the derivative of inverse tangent ($\frac{1}{1+x^2}$) and apply the chain rule to find the derivative of the equation: $y'=\frac{1}{1+(x^2)^2}\times2x=\frac{2x}{1+x^4}$