Arithmetic and Geometric Sequences

Is the following sequence Arithmetic, Geometric or Neither: 3, -1, -5, -9 ?

• Arithmetic

• Geometric

• Neither

Is the following sequence Arithmetic, Geometric or Neither: 3, -6, 12, -24, 48?

• Arithmetic

• Geometric

• Neither

Is the following sequence Arithmetic, Geometric or Neither:  $\frac{1}{2}x,\ \frac{1}{3}x^2,\ \frac{2}{9}x^3$  ?

• Arithmetic

• Geometric

• Neither

Is the following sequence Arithmetic, Geometric or Neither:  $2,\ 1,\ \frac{1}{2},\ \frac{1}{3},\ \frac{1}{4}$  ?

• Arithmetic

• Geometric

• Neither

Write the first 4 terms for the given recursive sequence :

 $a_1=2$   $a_n=3\cdot a_{\left(n-1\right)}-1$  .

 $\frac{1}{2},\ \frac{3}{4},\ 1,\ \frac{5}{4},..$  Find the common difference of the Arithmetic sequence.

•  $\frac{3}{2}$  

•  $\frac{1}{4}$  

• 1

•  $\frac{2}{3}$  

 $\$  Write an explicit formula for the previous Arithmetic Sequence: $\frac{1}{2},\ \frac{3}{4},\ 1,\ \frac{5}{4}$  ...

•  $a_n=\frac{1}{2}\left(\frac{1}{4}\right)^{\left(n-1\right)}$  

•  $a_n=\frac{1}{4}+\left(n-1\right)\cdot\frac{1}{2}$  

•  $a_n=\frac{1}{4}+a_{\left(n-1\right)}$  

•  $a_n=\frac{1}{2}+\left(n-1\right)\cdot\frac{1}{4}$  or  $a_n=\frac{1}{4}n+\frac{1}{4}$  

 $\$  Find the 25th term of the previous Arithmetic sequence: $\frac{1}{2},\ \frac{3}{4},\ 1,\ \frac{5}{4}$  ...

•  $\frac{25}{4}$  

•  $\frac{49}{4}$  

•  $\frac{13}{2}$  

• 6

 $a_n=6+2n$  Convert to recursive form:

•  $a_1=8;\ \ \ \ \ \ a_n=a_{\left(n-1\right)}+2$  

•  $a_n=a_{\left(n-1\right)}+2$  

•  $a_1=6;\ \ \ a_n=a_{\left(n-1\right)}+2$  

•  $a_n=2+a_{\left(n-1\right)}$  

The corner section of a football stadium has 7 seats in the first row and 5 more seats in the second row and 5 more seats in the third row etc.. How many seats will there be in the 30th row?

• 150

• 152

• 210

• 1050