Which recursive sequence would produce the sequence 3,−10,29,… ?a1=3 and an=−an−1−3a1=3 and an=−2an−1−4a1=3 and an=−4an−1−2a1=3 and an=−3an−1−1
Q. Which recursive sequence would produce the sequence 3,−10,29,… ?a1=3 and an=−an−1−3a1=3 and an=−2an−1−4a1=3 and an=−4an−1−2a1=3 and an=−3an−1−1
Test First Formula: Let's test each recursive formula given with the initial value a1=3 to see which one produces the sequence 3,−10,29,… .
Test Second Formula: First, we test the recursive formula an=−an−1−3 with a1=3. Calculate a2 using the formula: a2=−a1−3=−3−3=−6. This does not match the second term of the sequence, which is −10.
Test Third Formula: Since a2 does not match the second term of the sequence, we can eliminate the first recursive formula.Now, let's test the second recursive formula an=−2an−1−4 with a1=3.Calculate a2 using the formula: a2=−2a1−4=−2×3−4=−6−4=−10.This matches the second term of the sequence.
Test Fourth Formula: Now, calculate a3 using the second recursive formula: a3=−2a2−4=−2∗(−10)−4=20−4=16. This does not match the third term of the sequence, which is 29.
Conclusion: Since a3 does not match the third term of the sequence, we can eliminate the second recursive formula.Now, let's test the third recursive formula an=−4an−1−2 with a1=3.Calculate a2 using the formula: a2=−4a1−2=−4×3−2=−12−2=−14.This does not match the second term of the sequence, which is −10.
Conclusion: Since a3 does not match the third term of the sequence, we can eliminate the second recursive formula.Now, let's test the third recursive formula an=−4an−1−2 with a1=3.Calculate a2 using the formula: a2=−4a1−2=−4×3−2=−12−2=−14.This does not match the second term of the sequence, which is −10.Since a2 does not match the second term of the sequence, we can eliminate the third recursive formula.Now, let's test the fourth recursive formula an=−3an−1−1 with a1=3.Calculate a2 using the formula: an=−4an−1−20.This matches the second term of the sequence.
Conclusion: Since a3 does not match the third term of the sequence, we can eliminate the second recursive formula.Now, let's test the third recursive formula an=−4an−1−2 with a1=3.Calculate a2 using the formula: a2=−4a1−2=−4×3−2=−12−2=−14.This does not match the second term of the sequence, which is −10.Since a2 does not match the second term of the sequence, we can eliminate the third recursive formula.Now, let's test the fourth recursive formula an=−3an−1−1 with a1=3.Calculate a2 using the formula: an=−4an−1−20.This matches the second term of the sequence.Now, calculate a3 using the fourth recursive formula: an=−4an−1−22.This matches the third term of the sequence.
Conclusion: Since a3 does not match the third term of the sequence, we can eliminate the second recursive formula.Now, let's test the third recursive formula an=−4an−1−2 with a1=3.Calculate a2 using the formula: a2=−4a1−2=−4×3−2=−12−2=−14.This does not match the second term of the sequence, which is −10.Since a2 does not match the second term of the sequence, we can eliminate the third recursive formula.Now, let's test the fourth recursive formula an=−3an−1−1 with a1=3.Calculate a2 using the formula: an=−4an−1−20.This matches the second term of the sequence.Now, calculate a3 using the fourth recursive formula: an=−4an−1−22.This matches the third term of the sequence.Since the fourth recursive formula an=−3an−1−1 with a1=3 produces the correct second and third terms of the sequence, we can conclude that this is the correct recursive formula for the given sequence.
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