Let , be the distinct roots of the equation x2 - (t2 - 5t + 6 )x + 1 = 0, t R and an = n + n. Then the minimum value of a2023 + a2025a2024 is
- -1/2
- -1/4
- 1/4
- 1/2
Answer
(2) -1/4
Solution
Let p = t2 - 5t + 6; is a root 2 = p - 1
2023: 2025 = p 2024 - 2023; same for
Add: a2025 = p a2024 - a2023
a2023 + a2025a2024 = p = (t - 52 )2 - 14
minimum = - 14 (at t = 52)
Answer: (2)