Find the mistake in Limit

 

Question

 

Given that            and  ,

Find the value of

.

 

 

Find the mistake in the following “method”

 

Let 

From  ,          we get     4 x – 3 y = 6     (1)

From    ,        we get     x + y = 5         (2)

Solving (1) and (2), we get   x = 3, y = 2.

 

Therefore,

 

 

      The answer is correct but there is a big mistake in the concept of limit.

 

Can you find it ?                                   

Find the solution below.

 

 

The point is :

 

Although     and   exist,

the limits    may not exist.

 

The correct way :

     

(here by given the limits exist)

 

 

A small question :

 

How can you find   in the above calculation ?