Let be a real-valued function defined on the interval such that , for all , and let be the inverse function of f. Then is equal to
- (A)1
- (B)✓ Correct
- (C)
- (D)
Answer: (B)
Solution
Given .
At : , so . This means .
Differentiating both sides with respect to :
At :
Using the inverse function derivative formula:
At : , so . This means .
Differentiating both sides with respect to :
At :
Using the inverse function derivative formula:
JEE Advanced · 2010 · 11 Apr 2010 · Paper 2 · Single correct option