If f(x)=axf(x) = a^xf(x)=ax, which of the following is equal to f(x+h)−f(x)h\frac{f(x+h) - f(x)}{h}hf(x+h)−f(x)?
axah−1ha^x \frac{a^h-1}{h}axhah−1
ahax−1ha^h \frac{a^x-1}{h}ahhax−1
axln(a)a^x \ln(a)axln(a)
axha^x haxh