If the function and , then the value of is
Answer: 2
Solution
Since , we have .
Differentiating: , so .
We need . First find : since , we need for some .
, so .
Now , so .
Thus .
Differentiating: , so .
We need . First find : since , we need for some .
, so .
Now , so .
Thus .
JEE Advanced · 2009 · 12 Apr 2009 · Paper 2 · Integer answer