What is the derivative of the function f(x) = ( x7 + 4x3 ) / x4
$$\\f(x) =\frac{ ( x^7 + 4x^3 ) }{ x^4}\\\\ f(x) = x^3 + 4x^{-1} \\\\ f'(x) = 3x^2-4x^{-2} \\\\ f'(x) = 3x^2-\frac{4}{x^{2}} \\\\$$