(a)

Graph the four functions.

Graph of the function :

Graph of the function :

.

Graph of the function :

.

Graph of the function :

Observe the above graphs :

The functions and have the same graph.

(b)

The functions are and .

For , .

For , .

For , .

For , .

For ,

For ,

For all values of ,  .

The functions and have the same graph because .

(c)

The functions and .

 For , .

For ,

Negative value under square root is not defined.

The function is defined only for .

Thus, the graphs of and are not same.

(d)

The functions and .

For ,

For ,

The two functions have different values for .

Thus, the graphs and are not same.

(a) The functions and have the same graph.

(b) The functions and have the same graph because .

(c) The function is defined only for .

(d) The two functions have different values for .