218k views
2 votes
Write a rule for the nth term of the geometric sequence that have the following two terms.

a1 = 2 a3 = 50

User Awaken
by
3.9k points

1 Answer

3 votes

Answer:

Tn = 2 * ±5^(n-1)

where Tn is the nth term of the geometric sequence.

Explanation:

The geometric sequence is one in which there are changes between consecutive terms as a result of a common ratio.

A geometric sequence with a common ratio r and a as it's first term has an nth term defined as

Tn = ar^n-1 as such, if a1 = 2 a3 = 50 then

T3 = ar^3-1

50 = 2 * r²

r² = 25

r = ±5

The rule for the nth term may be written as

Tn = 2 * ±5^(n-1)

User Paul Beck
by
3.0k points