hey can someone check if this is correct. Just a differentiation of a function.

$\displaystyle

f (x) = 4x^5 - 13x + 8\sqrt[3]{x} - 9 + (\frac{4}{x}) - (\frac{5}{x^3})

$

differentiated to:

$\displaystyle

f '(x) = 20x^4 - 13 - 24x^{-4} - (\frac{4}{x^2}) - (\frac{15}{x^4})

$

correct?