1.2k views
6 votes
Find the 4th term in the following sequence (n = 4)

a1 = 8

an = an-1 - 3

1) 2
2) -1
3) 1

User Glenfant
by
7.0k points

1 Answer

9 votes

this formula, doesn't rely on a product, relies on a "sum", or is namely an arithmetic sequence, aₙ₋₁ -3 is another way of saying, the value of the previous term minus 3, so it relies on the ordinal value of a term, so is an recursive formula, well, let's get it when n = 4.


\begin{array}{ccll} order&term&value\\ \cline{1-3} 1&a_1&8\\ 2&a_2&a_(2-1)-3\\ &&a_1-3\\ &&8-3\\ &&5\\ 3&a_3&a_(3-1)-3\\ &&a_2-3\\ &&2\\ 4&a_4&a_(4-1)-3\\ &&a_3-3\\ &&2-3\\ &&-1 \end{array}

User Ric Tokyo
by
8.4k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories