Найти производную первого порядка (ln(sin(x/((x^4)-3*

(ln(sin( x/ (x^4 -3x)) )'=1/ sin (x/(x^4 -3x)) * (sin(x/(x^4 -3x) )'=
=1/sin(x/(x^4 -3x) ) * cos(x/(x^4 -3x) * (x/(x^4 -3x) )'=
=(cos(x/(x^4 -3x) ) /sin(x/(x^4 -3x))  * (1*(x^4 -3x)-x(4x^3-3) )/(x^4 -3x)^2=
=ctg (x/ (x^4 -3x) )  *(x^4 -3x  -4x^4+3x) /(x^4 -3x)^2=
=(-3x^4  *ctg(x/(x^4 -3x) ) ) /(x^4-3x)^2