Let (the set of all real numbers) be a function. Suppose the function is twice differentiable, and satisfies .
Which of the following is true for ?
Which of the following is true for ?
- (A)
- (B)
- (C)
- (D)✓ Correct
Answer: (D)
Solution
Let for .
Then and
So for all , meaning is strictly convex.
Since and , and is strictly convex, we have:
for all
Therefore , which gives for .
Since there's no lower bound specified, we have .
Then and
So for all , meaning is strictly convex.
Since and , and is strictly convex, we have:
for all
Therefore , which gives for .
Since there's no lower bound specified, we have .
JEE Advanced · 2013 · 02 Jun 2013 · Paper 2 · Single correct option