Answer: 7 years
Step-by-step explanation:
= In2 / ∧
since the half life is given , we have :
22 = In 2/ ∧
∧ = In2/22
∧ = 0.032
Recall the formula for half life:
=
Therefore:
0.80 =
Take the In of both sides
In 0.80 = - 0.032t
t = In 0.80 / - 0.032
t = 7 years
I hope first term is 1.
Hope this is your question, if not I think you will, still be able to
find an answer of your question based on this solution.
The formula for general term of a geometric sequence is,
Where, first term: a_{1} =1 and common ratio: r = -4.
So, first step is to plug in the values of a1 and r in the above formula to get the rule of this geometric sequence. Hence,
So, the rule of the geometric sequence is .
To find the seventh term, plug in n = 7 in the above rule. Therefore,
=
= 4096
Hope this helps you!.