Math Problem Statement

Which graph shows y = log2 x?

Solution

The question asks which graph represents the function y=log2xy = \log_2 x.

Key characteristics of the logarithmic function y=log2xy = \log_2 x:

  1. Domain: The function is only defined for x>0x > 0, so the graph must be entirely to the right of the y-axis.
  2. Vertical asymptote: There is a vertical asymptote at x=0x = 0, meaning the curve approaches but never touches or crosses the y-axis.
  3. Shape: The logarithmic graph increases slowly for larger values of xx but rapidly decreases near 0 on the positive x-axis.
  4. Intercept: The graph will pass through (1,0)(1, 0) because log2(1)=0\log_2(1) = 0.

Looking at the four graphs:

  • Top left: This graph is defined for negative x-values and approaches the x-axis from the left, which doesn't match a logarithmic function.
  • Top right: This is an exponential curve, not a logarithmic curve.
  • Bottom left: This is also incorrect as it represents a negative logarithmic-like shape.
  • Bottom right: This graph fits the description of y=log2xy = \log_2 x, defined only for x>0x > 0, with a vertical asymptote at x=0x = 0, and passing through (1,0)(1, 0).

Thus, the correct graph is the bottom right one.

Would you like more details or have any questions?

Here are five related questions to explore:

  1. How does the base of a logarithm affect the shape of its graph?
  2. What is the inverse of the function y=log2xy = \log_2 x?
  3. Can you explain the domain and range of logarithmic functions?
  4. How would the graph of y=log3xy = \log_3 x compare to y=log2xy = \log_2 x?
  5. What happens to the graph of y=log2xy = \log_2 x if you add a constant to the function (e.g., y=log2x+2y = \log_2 x + 2)?

Tip: When sketching logarithmic graphs, always check for the vertical asymptote at x=0x = 0 and where the function crosses the x-axis (at (1,0)(1, 0)).

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Logarithmic Functions
Graphs of Functions
Asymptotes

Formulas

y = log_b x (for general logarithmic functions)
y = log2 x (specific case)

Theorems

Properties of Logarithmic Functions
Vertical Asymptote of Logarithmic Graphs

Suitable Grade Level

Grades 10-12