\(=\lim\limits_{h\to0 }\frac{1-(x^4+4x^3h+6x^2h^2+4xh^3-h^4)-1+x^4}{h}\\ =\lim\limits_{h\to0 }\frac{1-x^4-4x^3h-6x^2h^2-4xh^3-h^4-1+x^4}{h}\\ =\lim\limits_{h\to0 }\frac{-4x^3h-6x^2h^2-4xh^3-h^4}{h}\\ =\lim\limits_{h\to0 }\frac{h\cdot(-4x^3-6x^2h-4xh^2-h^3)}{h}\\ =\lim\limits_{h\to0 }-4x^3-6x^2h-4xh^2-h^3\\ =-4x^3\)
Rechne zur Sicherheit nach.