The function .

Divide numerator and denominator by x .

.

To find the  values, use definition of limits at infinity.

If  is positive value, then  and , such that 

Squaring on each side.

Rewrite the above expression.

Therefore .

(a)

Find 

Now for  then

For  then .

(b)

Find 

Now for  then

For  then .

(a)  If  then .

(b) If  then .