HW. 2/8

Define arithmetic sequences.

• A sequence whose terms change by adding the same number each time.

• A sequence whose terms change by multiplying the same number each time.

• A sequence whose terms change by dividing the same number each time.

• A list of numbers that often (but not always) form a pattern.

Find the common ratio: 4, -16, 64, -256, ...

• r = -4
• r = 2
• r = -2
• r = 4

The first term in an arithmetic sequence is -8 and the common difference is 14.  What is the 28th term given the equation a_n = a₁ + d (n - 1)

• 378

• 1024

• -324

• 370

The first term in a geometric sequence is 160 and the common ratio is 1/2.  What is the 7th term given the equation a_n = a₁ (r)^n-1

• 5

• 2.5

• 10

• 1.25

What is the eleventh term of an arithmetic sequence in which a1 = 3 and d = 6?

• 63

• 39

• 69

• 36

If the first term of an arithmetic sequence is 5 and the common difference is 6, what are the first five terms?

• 5, 11, 17, 23, 29

• 6, 11, 16, 21, 26

• 5, 10, 15, 20, 25

• 5, 11, 15, 20, 26

Arithmetic, geometric, or neither?

4, 9, 14, 19, ...

• Arithmetic

• Geometric

• Neither

256, 128, 64, 32, ...

What's next?

• 24

• 18

• 16

• 8

Find the 25th term of the sequence if a₁ = 5 and d = 0.5

• 18
• 17
• 15
• 14

What is the explicit function for:
4, 7, 10, 13...

• f(n)=4(n-1)+3
• f(n)=3(n-1)+4
• f(n)=4(n-1)+13
• none of the above