Some arithmetic sequences are defined in terms of the previous term using a
recursive formula . The formula provides an algebraic rule for determining the terms of the sequence. A recursive formula allows us to find any term of an arithmetic sequence using a function of the preceding term. Each term is the sum of the previous term and the common difference. For example, if the common difference is 5, then each term is the previous term plus 5. As with any recursive formula, the first term must be given.
Recursive formula for an arithmetic sequence
The recursive formula for an arithmetic sequence with common difference
is:
Given an arithmetic sequence, write its recursive formula.
Subtract any term from the subsequent term to find the common difference.
State the initial term and substitute the common difference into the recursive formula for arithmetic sequences.
Writing a recursive formula for an arithmetic sequence
Write a
recursive formula for the
arithmetic sequence .
The first term is given as
. The common difference can be found by subtracting the first term from the second term.
Substitute the initial term and the common difference into the recursive formula for arithmetic sequences.
Do we have to subtract the first term from the second term to find the common difference?
No. We can subtract any term in the sequence from the subsequent term. It is, however, most common to subtract the first term from the second term because it is often the easiest method of finding the common difference.
Questions & Answers
if three forces F1.f2 .f3 act at a point on a Cartesian plane in the daigram .....so if the question says write down the x and y components ..... I really don't understand
a fixed gas of a mass is held at standard pressure temperature of 15 degrees Celsius .Calculate the temperature of the gas in Celsius if the pressure is changed to 2×10 to the power 4