Find the first six terms of the sequence. a1 = -6, an = 4.an - 1
Solution:
Given, the series is in geometric progression
First term, a1 = -6
an = 4.an - 1
We have to find the six terms of a finite sequence.
Geometric progression can be represented by the formula,
\(f(n) = a_{1}(r)^{n-1}\)
\(a_{2}=4\times a_{(2-1)}\\a_{2}=4\times a_{1}\\a_{2}=4\times (-6)\\a_{2}=-24\)
\(a_{3}=4\times a_{(3-1)}\\a_{3}=4\times a_{2}\\a_{3}=4\times (-24)\\a_{3}=-96\)
\(a_{4}=4\times a_{(4-1)}\\a_{4}=4\times a_{3}\\a_{4}=4\times (-96)\\a_{4}=-384\)
\(a_{5}=4\times a_{(5-1)}\\a_{5}=4\times a_{4}\\a_{5}=4\times (-384)\\a_{5}=-1536\)
\(a_{6}=4\times a_{(6-1)}\\a_{6}=4\times a_{5}\\a_{6}=4\times (-1536)\\a_{6}=-6144\)
Therefore, the six terms are -6, -24, -96, -384, -1536 and -6144.
Find the first six terms of the sequence. a1 = -6, an = 4.an - 1
Summary:
The first six terms of the sequence. a1 = -6, an = 4.an - 1 are -6, -24, -96, -384, -1536 and -6144.
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