Q. Find an explicit formula for the geometric sequence2,6,18,54,…. Note: the first term should be b(1).b(n)=□
Identify Sequence Type: Identify the type of sequence.The sequence 2,6,18,54,… is a geometric sequence because each term is obtained by multiplying the previous term by a constant ratio.
Find First Term and Ratio: Determine the first term b(1) and the common ratio r of the sequence.The first term is b(1)=2.To find the common ratio, divide the second term by the first term: r=26=3.
Write Explicit Formula: Write the explicit formula for the geometric sequence using b(1) and r. The explicit formula for a geometric sequence is b(n)=b(1)⋅r(n−1). Substitute b(1)=2 and r=3 into the formula. b(n)=2⋅3(n−1).
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