(a)

Squeeze Theorem :

If  when  is near to  and

 then .

The range of  is

Multiple with .

Apply .

From the Squeeze Theorem,

.

(b)

Graph :

Graph of the function  :

Observe the graph,

It touches asymptote at infinite times.

(a) .

(b) Graph of the function  is

The graph touches asymptote at infinite times.