The Number that will not be changed by derivatives

The Exponential Function

1. Exponential $e=1+1+{1 \over 2!}+{1 \over 3!}+{1 \over 4!}+{1 \over 5!}+{1 \over 6!}+{1 \over 7!}....$
2. Exponential Function $(e^{x})'=e^{x}$

so when every you meet Exponential just remind your self it will not changed by the derivatives

examples

ex1:$f(x)=e^{x}+x^{4}$ answer1:$f'(x)=e^{x}+4x^{3}$

ex2:$f(x)={e^{x} \over x}$ answer2: Failed to parse (syntax error): {\displaystyle f'(x)={ x e^x - e^x \over x^2 }