(a)

where .

Observe the graph:

As  tends to  from right hand side,  approaches to .

.

(b)

where .

Observe the graph:

As tends to  from left hand side,  approaches to .

.

(c)

where .

Observe the graph:

Since the left hand limit and right hand limit are equal, the limit exists.

.

is continuous on the interval .

(a) .

(b) .

(c) .

is continuous on the interval .