Arithmetic Sequences In an arithmetic sequence, the difference between consecutive terms is constant. The difference is called the common difference. To find d: 2nd term – 1st term
Arithmetic? 2, 4, 8, 16 6, 12, 18 48, 45, 42 2, 5, 7, 12
Arithmetic Sequence Formulas Recursive Formula an = an-1 + d Explicit Formula an = a1 + (n-1)d an = nth term a1 = 1st term n = number of terms d = common difference
Examples Find the 20th term of each sequence 213, 201, 189, 177… .0023, .0025, .0027…
More examples Find the 17th term of the sequence: a16 = 18, d = 5
Find the missing term Use arithmetic mean = average! 84, _______, 110 24, _______, 57