Unit 3 – Exponential Functions 
3.1 Exponential Sequences
Exponential Sequence Vocab: 
• Exponential Sequence: Sequence where 
terms are multiplied by some number to 
find the next term 
• Growth/Decay Factor: what each term is 
being multiplied by 
▫ > 1 for exponential growth 
▫ < 1 for exponential decay 
• Starting Value: the first term in the 
sequence 
• Formula: tells how to find the next term 
▫ Example: next = now x 2
Example 1 
• 2, 8, 32, 128, … 
• starting value: ______ 
•growth/decay factor: ______ 
•formula for next term: 
next = now ______ 
• next term: _____
You Try! 
• 6, 18, 54, 162, … 
• starting value: ______ 
•growth/decay factor: ______ 
•formula for next term: 
next = now ______ 
• next term: _____
Example 2 
• 4, 2, 1, ½, … 
• starting value: ______ 
•growth/decay factor: ______ 
•formula for next term: 
next = now ______ 
• next term: _____
You Try! 
• 6, 2, 2/3, 2/9, … 
• starting value: ______ 
•growth/decay factor: ______ 
•formula for next term: 
next = now ______ 
• next term: _____
Example 3 
• 0.5, 1.5, 4.5, 13.5, … 
• starting value: ______ 
•growth factor: ______ 
•formula for next term: 
next = now ______ 
• next term: _____
You Try! 
• 0.25, 1.25, 6.25, 31.25, … 
• starting value: ______ 
•growth factor: ______ 
•formula for next term: 
next = now ______ 
• next term: _____
Other Sequence Names 
•Linear sequences 
▫same # added each time 
▫ Also called ARITHMETIC 
•Exponential sequences 
▫Same # multiplied each time 
▫ Also called GEOMETRIC
Identifying Exponential Sequences 
•Tell if each sequence is linear, 
exponential, or neither: 
• 4, 24, 144, 864, … 
• 9, 16, 25, 36, … 
• 5, 4.5, 4, 3.5, … 
•
Writing Sequences 
•From a given verbal description: 
•Find the starting value – this is the 
first term 
• Find the growth/decay factor – 
multiply the first term by that # 
•Keep multiplying until you have 4 
terms
Example 4 
•Write a sequence to match: 
•A population of bacteria will triple 
every month. There are currently 450 
bacteria present.
You Try! 
•You currently have $85 and you 
will spend half your money each 
week.

3.1 exponential sequences

  • 1.
    Unit 3 –Exponential Functions 3.1 Exponential Sequences
  • 2.
    Exponential Sequence Vocab: • Exponential Sequence: Sequence where terms are multiplied by some number to find the next term • Growth/Decay Factor: what each term is being multiplied by ▫ > 1 for exponential growth ▫ < 1 for exponential decay • Starting Value: the first term in the sequence • Formula: tells how to find the next term ▫ Example: next = now x 2
  • 3.
    Example 1 •2, 8, 32, 128, … • starting value: ______ •growth/decay factor: ______ •formula for next term: next = now ______ • next term: _____
  • 4.
    You Try! •6, 18, 54, 162, … • starting value: ______ •growth/decay factor: ______ •formula for next term: next = now ______ • next term: _____
  • 5.
    Example 2 •4, 2, 1, ½, … • starting value: ______ •growth/decay factor: ______ •formula for next term: next = now ______ • next term: _____
  • 6.
    You Try! •6, 2, 2/3, 2/9, … • starting value: ______ •growth/decay factor: ______ •formula for next term: next = now ______ • next term: _____
  • 7.
    Example 3 •0.5, 1.5, 4.5, 13.5, … • starting value: ______ •growth factor: ______ •formula for next term: next = now ______ • next term: _____
  • 8.
    You Try! •0.25, 1.25, 6.25, 31.25, … • starting value: ______ •growth factor: ______ •formula for next term: next = now ______ • next term: _____
  • 9.
    Other Sequence Names •Linear sequences ▫same # added each time ▫ Also called ARITHMETIC •Exponential sequences ▫Same # multiplied each time ▫ Also called GEOMETRIC
  • 10.
    Identifying Exponential Sequences •Tell if each sequence is linear, exponential, or neither: • 4, 24, 144, 864, … • 9, 16, 25, 36, … • 5, 4.5, 4, 3.5, … •
  • 11.
    Writing Sequences •Froma given verbal description: •Find the starting value – this is the first term • Find the growth/decay factor – multiply the first term by that # •Keep multiplying until you have 4 terms
  • 12.
    Example 4 •Writea sequence to match: •A population of bacteria will triple every month. There are currently 450 bacteria present.
  • 13.
    You Try! •Youcurrently have $85 and you will spend half your money each week.