Let’s go step by step to fill in the blanks for both exponential growth and decay functions.
---
First, let’s look at Exponential Growth Function:
Given: \( f(x) = 2^x \)
#### Graph behavior:
- As x increases (goes right), y gets bigger → so it’s
increasing from left to right.
- The graph never touches the x-axis — it gets closer and closer but never reaches it. That means the
asymptote is at y = 0.
- Domain: You can plug in any real number for x →
all real numbers, or \( (-\infty, \infty) \)
- Range: Since \( 2^x \) is always positive, y > 0 →
(0, ∞)
- Y-intercept: When x = 0, \( f(0) = 2^0 = 1 \) → so y-intercept is
1
✔ So for Exponential Growth:
- increasing from left to right
- asymptote at y = 0
- domain: all real numbers
- range: y > 0
- y-intercept: 1
---
Now, Exponential Decay Function:
Given: \( f(x) = \left(\frac{1}{2}\right)^x \)
Note: This is the same as \( 2^{-x} \), which decreases as x increases.
#### Graph behavior:
- As x increases (goes right), y gets smaller → so it’s
decreasing from left to right.
- Again, the graph approaches the x-axis but never touches it →
asymptote at y = 0
- Domain: Still any real number →
all real numbers
- Range: Always positive →
y > 0
- Y-intercept: When x = 0, \( f(0) = \left(\frac{1}{2}\right)^0 = 1 \) → y-intercept is
1
✔ So for Exponential Decay:
- decreasing from left to right
- asymptote at y = 0
- domain: all real numbers
- range: y > 0
- y-intercept: 1
---
Now let’s also fill in the definitions at the top:
>
asymptote – a
line that a graphed function approaches but never
touches
>
exponential growth function – an exponential function where b is
greater than
1
> example: \( f(x) = 2^x \) (already given)
>
exponential decay function – an exponential function where b is
between 0 and 1
> example: \( f(x) = \left(\frac{1}{2}\right)^x \) (already given)
---
Final Answer:
Top Section Definitions:
- asymptote – a
line that a graphed function approaches but never
touches
- exponential growth function – an exponential function where b is
greater than
1
- exponential decay function – an exponential function where b is
between 0 and 1
Exponential Growth Function Table:
-
increasing from left to right
- asymptote at
y = 0
- domain:
all real numbers
- range:
y > 0
- y-intercept:
1
Exponential Decay Function Table:
-
decreasing from left to right
- asymptote at
y = 0
- domain:
all real numbers
- range:
y > 0
- y-intercept:
1
Parent Tip: Review the logic above to help your child master the concept of exponential growth and decay worksheet.