Ques. 1JEE Main 2024, 27 January (Evening Shift)
If , are the roots of the equation, x2-x-1=0 and Sn=2023 n+2024 n, then :
- 2S12=S11+S10
- S12=S11+S10
- S11=S10+S12
- 2S11=S12+S10
Answer
(2) S12=S11+S10
Solution
2= +1 n= n-1+ n-2 (multiply by n-2); same for
2023 n+2024 n= (2023 n-1+2024 n-1 )+ (2023 n-2+2024 n-2 )
Sn=Sn-1+Sn-2
Put n=12: S12=S11+S10
Answer: (2)