Find the derivative of f(x) = 99x at x = 100.

Given: f(x) = 99x

By using the derivative formula,

\( \lim\limits_{h \to 0} \dfrac{99(100+h)-99\times 100}{h}\)

\( \lim\limits_{h \to 0} \dfrac{99h}{h}\)

\( \lim\limits_{h \to 0} 99=99\)

Hence,

Derivative off(x) = 99x at x = 100 is 99