Math Problem Statement

Sketching the graph of f(x) = (1/2)^x

Solution

The function given is:

f(x)=(12)xf(x) = \left(\frac{1}{2}\right)^x

To sketch the graph of this function, let's analyze it step-by-step.

1. General Shape and Properties

The function f(x)=(12)xf(x) = \left(\frac{1}{2}\right)^x is an exponential function with a base less than 1. This means it represents exponential decay, where the value of f(x)f(x) decreases as xx increases.

2. Key Points

Let's calculate a few key points to help with sketching the graph:

  • When x=0x = 0: f(0)=(12)0=1f(0) = \left(\frac{1}{2}\right)^0 = 1
  • When x=1x = 1: f(1)=(12)1=12f(1) = \left(\frac{1}{2}\right)^1 = \frac{1}{2}
  • When x=1x = -1: f(1)=(12)1=2f(-1) = \left(\frac{1}{2}\right)^{-1} = 2
  • When x=2x = 2: f(2)=(12)2=14f(2) = \left(\frac{1}{2}\right)^2 = \frac{1}{4}

These points provide a good guide for plotting.

3. Asymptote

Since the base is between 0 and 1, as xx \to \infty, f(x)f(x) approaches 0 but never actually reaches it. Thus, the x-axis (or y=0y = 0) is a horizontal asymptote.

4. Sketching the Graph

The graph should:

  • Pass through the points (0,1)(0, 1), (1,12)(1, \frac{1}{2}), (1,2)(-1, 2), etc.
  • Approach the x-axis as xx \to \infty (exponential decay).
  • Show rapid growth for negative values of xx, where f(x)f(x) increases as xx becomes more negative.

Would you like me to provide a visual sketch of this graph?


Further Questions to Explore:

  1. How does changing the base from 12\frac{1}{2} to another fraction (e.g., 13\frac{1}{3}) affect the graph?
  2. What happens to the graph if the base is changed to a value greater than 1 (e.g., f(x)=2xf(x) = 2^x)?
  3. How would the graph change if the function were multiplied by a constant, like f(x)=3(12)xf(x) = 3 \left(\frac{1}{2}\right)^x?
  4. What would the graph look like if we added a constant to the function, like f(x)=(12)x+1f(x) = \left(\frac{1}{2}\right)^x + 1?
  5. Can you determine the equation of the line tangent to the graph at x=0x = 0?

Tip: When sketching exponential decay functions, remember that the graph always gets closer to the x-axis but never actually touches it. This helps in visualizing the asymptotic behavior.

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Math Problem Analysis

Mathematical Concepts

Exponential Functions
Graphing
Asymptotic Behavior

Formulas

f(x) = a^x (where 0 < a < 1 for exponential decay)

Theorems

Properties of Exponential Functions

Suitable Grade Level

Grades 9-12