y'=[(4x^3+2x)(x^2+2)/(x^4+x^2)
-2xln(x^4+x^2)]/[x^2+2]^2
=[(4x^3+2x)(x^2+2)
-2x^3(x^2+1)ln(x^4+x^2)]
/[(x^2+2)^2(x^4+x^2)]
=[(4x^2+2)(x^2+2)
-2x^2(x^2+1)ln(x^4+x^2)]
/[(x^2+2)^2(x^3+x)]