In an A.P., the sixth term . If the product is the greatest, then the common difference of the A.P. is equal to
- (A)
- (B)✓ Correct
- (C)
- (D)
Answer: (B)
Solution
.
Expanding: .
Setting : .
: at , (maximum); at , (minimum).
So the product is greatest at .
Key confirmed: B.
Expanding: .
Setting : .
: at , (maximum); at , (minimum).
So the product is greatest at .
Key confirmed: B.

JEE Main · 2024 · 29 Jan 2024 · Shift 1 · Single correct option