Answer:
a) Explicit Formula : aₙ = 3. (-3)ⁿ⁻¹
b) Fifth term : a₅ = 243
Step-by-step explanation:
This sequence above is the Geometric sequence. The Geometric sequence is calculated using the formula
aₙ= a1.rⁿ⁻¹
where a1 = first term
r = common ratio
n = number of terms
From the above question, we are given
a1= 3, r=-3 and asked to find the explicit formula.
The explicit formula using the geometric sequence formula =
aₙ = 3. (-3)ⁿ⁻¹
b) The fifth term in the sequence is calculated as
aₙ = 3. (-3)ⁿ⁻¹
Where n = 5
a₅ = 3.(-3)⁵⁻¹
a₅ = 3.(-3)⁴
a₅= 243
