The function is , where is the wall thickness in meters.

(a).

Find .

Substitute in .

The function is defined for .

Find if exists.

Construct a table that shows the values of for -values approaching from the left and from the right. 

Observe the table the value:

As tends to from the left and from the right , approaches to .

.

Observe above two conditions,

Since , is continuous at .

 (b).

The function .

Domain of above rational function is all real numbers except zero.

is undefined.

 The function is discontinues at .

Since is the wall thickness, the function does not have to be examined for the negative values.

Construct a table of for different values of approaching from the right.

Observe the table the value, as tends to from the right , approaches to .

  is discontinues at and has infinite discontinuity at .

(c).

Graph of the function :

 Observe the graph:

As tends to from the right , approaches to .

(a). is continuous at .

(b). The function is discontinues at and has infinite discontinuity at .

(c). Graph of the function :

.