Differentiate y=sin(x)/5x^3 with respect to x

In order to complete this question we need to use the quotient rule (i.e. if an equation is of the form h(x)=f(x)/g(x) then h'(x)=(g(x)f'(x)-g'(x)f(x))/g(x)^2).In our example f'(x)=cos(x),g'(x)=15x^2, therefore dy/dx=(5x^3cos(x)-15x^2sin(x))/25x^6