# Daily Check Find the first 3 terms of the following sequence:

## Presentation on theme: "Daily Check Find the first 3 terms of the following sequence:"— Presentation transcript:

Daily Check Find the first 3 terms of the following sequence:
Write the formula for the following arithmetic sequence. -2, 1, 4, 7, 10

How is a geometric sequence like an exponential function?
Math II UNIT QUESTION: How is a geometric sequence like an exponential function? Standard: MM2A2, MM2A3 Today’s Question: How is a geometric sequence like an exponential function? Standard: MM2A3f,g

Sequences and Series

Geometric Sequences In geometric sequences, you multiply by a common ratio each time. 1, 2, 4, 8, 16, ... multiply by 2 27, 9, 3, 1, 1/3, ... Divide by 3 which means multiply by 1/3

Geometric Sequences Find the 8th term of the sequence: 2,6,18,…
Determine the pattern: Multiply by 3 (known as the common ratio) Write the new sequence: 2,6,18,54,162,486,1458,4374 So the 8th term is 4374.

Geometric Sequences Again, use a formula to find large numbers.
an = a1 • (r)n-1

Geometric Sequences Find the 10th term of the sequence : 4,8,16,…
an = a1 • (r)n-1 a1 = 4 r = 2 n = 10

Geometric Sequences an = a1 • (r)n-1 a10 = 4 • (2)10-1 a10 = 4 • (2)9

Geometric Sequences Find the ninth term of a sequence if
a3 = 63 and r = -3 a1= ? n= 9 r = -3 a9 = ? There are 2 unknowns so you must…

Geometric Sequences First find t1.
Use the sequences formula substituting t3 in for tn.  a3 = 63 a3 = a1 • (-3)3-1 63 = a1 • (-3)2 63= a1 • 9 7 = a1

Geometric Sequences Now that you know t1, substitute again to find tn.
an = a1 • (r)n-1 a9 = 7 • (-3)9-1 a9 = 7 • (-3)8 a9 = 7 • 6561 a9 = 45927

Class work Day 1: Workbook p. 159 #1-9, 13-15, 19 odd

Homework Page 145 #2-16 (even)

Download ppt "Daily Check Find the first 3 terms of the following sequence:"

Similar presentations