Q. Write an explicit formula that represents the sequence defined by the following recursive formula:a1=−5 and an=an−1+3Answer: an=
Initial Term and Recursive Formula: The first term of the sequence is given as a1=−5. To move from one term to the next, we add 3 each time according to the recursive formula an=an−1+3.
Finding Next Terms: Let's find the next few terms to identify a pattern:a2=a1+3=−5+3=−2a3=a2+3=−2+3=1a4=a3+3=1+3=4We can see that each term is 3 more than the previous term.
Expressing nth Term: Now, let's express the nth term in terms of the first term and the common difference (which is 3):an=a1+(n−1)×3We know a1=−5, so we substitute that into the equation:an=−5+(n−1)×3
Simplifying Equation: Simplify the equation:an=−5+3n−3an=3n−8This is the explicit formula for the given recursive sequence.
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