The function , defined by , is
- (A)one-one and onto.
- (B)onto but not one-one.✓ Correct
- (C)one-one but not onto.
- (D)neither one-one nor onto.
Answer: (B)
Solution
. So is increasing on and decreasing on . Since has a local maximum at , it is not one-one (many-one). We have , , . The range is , which equals the codomain, so is onto.
JEE Advanced · 2012 · 08 Apr 2012 · Paper 1 · Single correct option