Let $\alpha$ and $\beta$ be the roots of the equation, 5x2 + 6x – 2 = 0. If Sn = $\alpha$n + $\beta$n, n = 1, 2, 3,....., then :
(1) 6S6 + 5S5 = 2S4
(2) 5S6 + 6S5 = 2S4
(3) 5S6 + 6S5 + 2S4 = 0
(4) 6S6 + 5S5 + 2S4 = 0
If you are commenting for the first time, please read the guidelines.
If you are answering for the first time, please read the guidelines.
Ans. (2) 5S6 + 6S5 = 2S4
Sol. 5$\alpha$2 + 6$\alpha$ = 2
5S6 + 6S5 = $\alpha$4(5$\alpha$2 + 6$\alpha$) + $\beta$4(5$\beta$2 + 6$\beta$)
= 2($\alpha$4 + $\beta$4) = 2S4
1.1k questions
772 answers
366 comments
78 users