Q. If a1=2,a2=5 and an=2an−1−an−2 then find the value of a5.Answer:
Find a3: Use the given recursive formula to find a3. The recursive formula is an=2an−1−an−2. We know a1=2 and a2=5. Calculate a3 using the formula. a3=2a2−a1=2×5−2=10−2=8.
Find a4: Use the recursive formula to find a4. We now know a2=5 and a3=8. Calculate a4 using the formula. a4=2a3−a2=2×8−5=16−5=11.
Find a5: Use the recursive formula to find a5. We now know a3=8 and a4=11. Calculate a5 using the formula. a5=2a4−a3=2×11−8=22−8=14.
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