IM1 Review: Arithmetic vs. Geometric

Sequences

100

Determine whether the sequence is arithmetic, geometric, or neither. State the rule and find the next 3 terms.

-83, -76, -70, -65, -61, ...

Neither

Adding decreasing consecutive numbers starting with 7. (+7, +6, +5, ...) 

-58, -56, -55

200

Determine whether the sequence is arithmetic, geometric, or neither. State the rule and find the next 3 terms. 

2/3, 2,6,18, ...

Geometric

Multiply by 3

54, 162, 486

300

Determine whether the sequence is arithmetic, geometric, or neither. State the rule and find the next 3 terms. 

25, 18, 11, 4, ...

Arithmetic

Subtract 7

-3, -10, -17

Recursive Rule

100

Write the recursive rule for the sequence.

3, 9, 15, 21, 27, ...

a_1=3, a_n=a_(n-1)+6

200

Write the recursive rule for the sequence. 

324, 108, 36, 12, ...

a_1=324, a_n=1/3a_(n-1)

300

Write the first 6 terms for the recursive formula. 

a_1=13, a_n=a_(n-1)+11

13, 24, 35, 46, 57, 68

400

Write the recursive rule for the sequence. 

a_n=4(1/2)^n

a_1=2, a_n=1/2a_(n-1)

Elicit Rule

100

Write the equation for the n^th term of the sequence. 

-3, 12, -48, 192, ...

a_n=-3(-4)^(n-1)

200

Write the equation for the n^th rule for the sequence. 

14, 17, 20, 23, ...

a_n=3n+11

300

Write the equation for the n^th rule for the sequence. 

-2, -15, -28, -41, ....

a_n=-13n+11

400

Write the equation for the n^th rule for the sequence. 

625, 250, 100, 40, ...

a_n=625(2/5)^(n-1)

Finding the nth term

100

Find the 95^th term of the arithmetic sequence. 

400, 392, 384, 376, 368, ...

-352

200

Find the 22^nd term of the geometric sequence where a₁=256 and r = ¹/₂

0.00012207 or 

1/8192

300

Find the 67^th term of the arithmetic sequence where a₁=47 and the common difference is -0.5.

14

400

Write the rule for the n^th term given the recursive formula 

a_1=29, a_n=a_(n-1)+19

a_n=19n+10