Unit 6 Exponential Functions

• The common ratio

• r

• The first term

• The number of the term

• n

• The nth term

Reorder the following

How do you find the comon ratio for 10,20,40,80...

• That tells you the common ratio is 2

• Identify the 2nd term, 20

• Test that... 20*2=40

  Check!

• Divide by the 1st term, 10

How do I know that a common ratio is negative?

• Every number in the sequence is negative

• Every other number in the sequence is negative

• Every number in the sequence is positive

• The difference between two consecutive numbers is negative

True or false

This sequence is geometric:

500, 100, 20, 4, .8....

• True, it goes up at the same rate

• False

• True, it goes down at the same rate

• Now you must divide to get the common ratio, -1

• Then identify the 1st term, 12

• Now you have the first term, find the ratio

• Next, identify the first term

• 81
• 3
• 243
• 6th
• 729

• 1
• -5
• 3rd
• 25
• -125

• -2

• 12

• 5

• -5

• -2

• 12

• 5

• -5