CHAPTER 11
SECTION 11.2
Arithmetic and Geometric Sequences
MINI LESSON
Arithmetic and Geometric Sequences
An arithmetic sequence changes by a constant difference between consecutive terms.
A geometric sequence changes by multiplying by a constant ratio.
Arithmetic sequences can be written using the formula \(a_n = a_1 + d(n-1)\).
Geometric sequences can be written using the formula \(a_n = a_1 r^{n-1}\).
Question 1
The equation that represents the sequence \(-2,-5,-8,-11,-14,\ldots\) is
Question 2
In an arithmetic sequence, the first term is \(25\) and the third term is \(15\). What is the tenth term in this sequence?
Question 3
Which equation represents the sequence \(12,6,3,\frac{3}{2},\ldots\), where \(a_1=12\)?
Answer Key
Arithmetic and Geometric Sequences
- 1.B. \(a_n=-2+(-3)(n-1)\)
- 2.A. \(-20\)
- 3.A. \(a_n=12\left(\frac{1}{2}\right)^{n-1}\)