If 
For what integers m and n does both 
and 
exist?
Given function is 
:
⇒ 
⇒ 
∴ 
exists if n = m.
Now 
:
⇒ 
⇒ 
∴ 
∴ 
exists for any integral value of m and n.
37
If For what integers m and n does both and exist?
Given function is
:
⇒
⇒
∴ exists if n = m.
Now :
⇒
⇒
∴
∴ exists for any integral value of m and n.