http://en.wikipedia.org/wiki/Differential_of_a_function English English English English English English English English Differential of a function Differential of a function http://en.wikipedia.org/wiki/Differential_of_a_function http://en.wikipedia.org/wiki/Differential_of_a_function the differential of a function Różniczka https://en.wikipedia.org/wiki/Differential_of_a_function English English English https://en.wikipedia.org/wiki/Differential_of_a_function English http://en.wikipedia.org/wiki/Differential_of_a_function the differential of a function https://en.wikipedia.org/wiki/Differential_of_a_function English http://en.wikipedia.org/wiki/Differential_of_a_function English http://en.wikipedia.org/wiki/Differential_of_a_function