Answer:
- an = 3(-2)^(n-1)
- 3, -6, 12, -24, 48
Explanation:
These variable names, a1, r, are commonly used in relationship to geometric sequences. We assume you want the terms of a geometric sequence with these characteristics.
a1 is the first term. r is the ratio between terms, so is the factor to find the next term from the previous one.
a1 = 3 (given)
a2 = a1×r = 3×(-2) = -6
a3 = a2×r = (-6)(-2) = 12
a4 = a3×r = (12)(-2) = -24
a5 = a4×r = (-24)(-2) = 48
The first 5 terms are 3, -6, 12, -24, 48.
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The explicit formula for the terms of a geometric sequence is ...
an = a1×r^(n -1)
Using the given values of a1 and r, the explicit formula for this sequence is ...
an = 3(-2)^(n -1)