Geometric Sequence

Which of the following sequences is geometric?

• -3, 3, -9, 15, ...

• -1, 1, 4, 8, ....

• 1, -5, 25, -125, ...

• 10, 12, 15, 19, ...

Tags

CCSS.HSF.BF.A.2

What is the common ratio of the sequence -4,12, -36, 108, ...?

• 2

• -2

• 3

• -3

Which of the following formulas would generate the sequence 2, -10, 50, -250, ....?

• $a_n=2\left(-5\right)^{\left(n-1\right)}$

• $a_n=-2\left(-5\right)^{\left(n-1\right)}$

• $a_n=-2\left(5\right)^{\left(n-1\right)}$

• $a_n=2\left(-5\right)^n$

Tags

CCSS.HSF.BF.A.2

CCSS.HSF.IF.A.3

Which of the following is the 8th term of the sequence 4, -8, 16, -32, ...?

• -256

• 512

• -1024

• 2048

Find the next three term of the sequence  $-3,\ -2,\ -\frac{4}{3},\ -\frac{8}{9},\ ...$  

•  $-\frac{64}{81},-\frac{128}{243},-\frac{256}{729}$  

•  $-\frac{16}{27},\ -\frac{32}{81},\ -\frac{64}{243}$  

•  $-\frac{80}{81},-\frac{160}{243},-\frac{320}{729}$  

•  $\frac{64}{81},\frac{128}{243},\frac{256}{729}$  

Find the 10th term of the sequence 0.5, 1, 2, 4, ...

• 512

• 1024

• 2048

• 4096

Tags

CCSS.HSF.BF.A.2

The 1st term of a geometric sequence is -2 and the 4th term is -128. What is the common ratio?

• 2

• 3

• 4

• -4

The 2nd term of a geometric sequence is 6 and the 5th term is 162. What is the common ratio of the sequence?

• 2

• -2

• 3

• 4

The first term of a geometric sequence is  $\frac{4}{3}$  and the common ratio is  $\frac{1}{3}$  . What is the 5th term?

•  $\frac{4}{81}$  

•  $\frac{4}{243}$  

•  $\frac{4}{729}$  

•  $\frac{1}{729}$  

Tags

CCSS.HSF.BF.A.2

CCSS.HSF.IF.A.3

CCSS.HSF.LE.A.2

The 4th term of a geometric sequence is -75 and the common ratio is -5. What is the explicit formula of the sequence?

• $a_n=\frac{3}{5}\left(-5\right)^{\left(n-1\right)}$

• $a_n=\frac{2}{5}\left(5\right)^{\left(n-1\right)}$

• $a_n=\frac{1}{5}\left(-5\right)^{\left(n-1\right)}$

• $a_n=\frac{3}{2}\left(-5\right)^{\left(n-1\right)}$