Graph:

Solution (a) To graph $f( x) =\log _{2}x$, graph $y=2^{x}$ and reflect it about the line $y=x.$ See Figure 66(a).

(b) To graph $f( x) =\log _{1/3}x$, graph $y=\left( \dfrac{1}{3}\!\right) ^{\!\!\!x}$ and reflect it about the line $y=x.$ See Figure 66(b).

(c) To graph $F( x) =\ln x$, graph $y=e^{x}$ and reflect it about the line $y=x$. See Figure 66(c).

Figure 66