Can someone help me with this derivative problem

y=sin(x^(1/3))+(sin(6x))^(1/3)

I've worked it out quite a few times, only to get the wrong answer =/

how do you know its wrong if you don`t know the answer ;)
y'(x)= cos(x^(1/3))/(3x^(2/3) ) + 6cos(6x)/ (3(sin(6x))^(2/3))