If 
, prove that x = f(y).
Given: 
Need to prove: x = f(y)
Replacing x by y in the function,
Now, given in the problem that y = f(x)
⇒ 
⇒ 
⇒ 
⇒ 
[Proved]
1
If , prove that x = f(y).
Given:
Need to prove: x = f(y)
Replacing x by y in the function,
Now, given in the problem that y = f(x)
⇒
⇒
⇒
⇒ [Proved]