Which recursive sequence would produce the sequence 3,−19,91,… ?a1=3 and an=−6an−1−1a1=3 and an=−5an−1−4a1=3 and an=−an−1−6a1=3 and an=−4an−1−5
Q. Which recursive sequence would produce the sequence 3,−19,91,… ?a1=3 and an=−6an−1−1a1=3 and an=−5an−1−4a1=3 and an=−an−1−6a1=3 and an=−4an−1−5
Identify First Term: Identify the first term of the sequence.The first term given is a1=3.
Calculate Second Term: Calculate the second term using each recursive formula and compare with the given second term −19.Using the first formula: an=−6an−1−1a2=−6a1−1=−6×3−1=−18−1=−19
Verify Second Term: Verify if the second term calculated in Step 2 matches the given second term.The calculated second term using the first formula is −19, which matches the given second term.
Calculate Third Term: Calculate the third term using the first recursive formula to verify if it matches the given third term (91).a3=−6a2−1=−6∗(−19)−1=114−1=113
Check Third Term: Check if the third term calculated in Step 4 matches the given third term. The calculated third term using the first formula is 113, which does not match the given third term (91).
Test Second Formula: Since the first formula did not produce the correct third term, test the second formula.Using the second formula: an=−5an−1−4a2=−5a1−4=−5×3−4=−15−4=−19
Verify Second Term: Verify if the second term calculated in Step 6 matches the given second term. The calculated second term using the second formula is −19, which matches the given second term.
Calculate Third Term: Calculate the third term using the second recursive formula to verify if it matches the given third term (91).a3=−5a2−4=−5∗(−19)−4=95−4=91
Check Third Term: Check if the third term calculated in Step 8 matches the given third term.The calculated third term using the second formula is 91, which matches the given third term.
Final Conclusion: Since the second formula has produced the correct second and third terms, we conclude that this is the correct recursive formula for the sequence.The correct recursive sequence formula is a1=3 and an=−5an−1−4.
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