Arithmetic sequences is a part of syllabus in algebra 1 (second math course), which finds application in many algebra questions including algebra word problems. An arithmetic progression (AP) or arithmetic sequence is a sequence of numbers, whose consecutive numbers differ by a constant. When n terms of an arithmetic sequence are added, you get arithmetic series. Arithmetic series formula is given by : sum = n/2 (a + l) where a is the 1st term and l is the last term. Learn more about Arithmetic sequences using the resources on this page.
The apps, sample questions, videos and worksheets listed below will help you learn Arithmetic Sequences.
Recursive formula: This sequence is neither arithmetic nor geometric. It does, however, have a pattern of development based upon each previous term. Notice how the value of n is used as the exponent for the value (-1).
Imagine we want to find a formula for the nth term of this sequence: 7, 11, 15, 19, 23, … We can see that the terms in this sequence go up by 4 each time, so 4n must appear in the formula. The sequence generated by the formula 4n is the four times table, but it isn’t quite the sequence we want: 4n sequence:
A recursive formula designates the starting term, a1, and the nth term of the sequence, an , as an expression containing the previous term (the term before it), an-1. The process of recursion can be thought of as climbing a ladder.
To find the common ratio, divide the second term by the first term. Notice the non-linear nature of the scatter plot of the terms of a geometric sequence. The domain consists of the counting numbers 1, 2, 3, 4, … and the range consists of the terms of the sequence.