Q. If a1=4,a2=2 and an=2an−1+an−2 then find the value of a6.Answer:
Understand recursive formula: Understand the recursive formula and initial conditions.The recursive formula given is an=2an−1+an−2, which means each term is the sum of twice the previous term and the term before that. We are given a1=4 and a2=2 as initial conditions.
Find a3: Find a3 using the recursive formula.a3=2a2+a1( = 2\times 2 + 4(\newline\) = 4 + 4(\newline\) = 8\)
Find a4: Find a4 using the recursive formula.a4=2a3+a2=2×8+2=16+2=18
Find a5: Find a5 using the recursive formula.a5=2a4+a3=2×18+8=36+8=44
Find a6: Find a6 using the recursive formula.a6=2a5+a4( = 2\times44 + 18(\newline\) = 88 + 18(\newline\) = 106\)
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