Parent Graphs and Transformations of Logarithmic Functions
This section introduces the parent graphs for logarithmic functions and explores how to graph transformed logarithmic functions.
The lesson presents two cases:
- Graph of fx = log_b x for b > 1
- Graph of fx = log_b x for 0 < b < 1
Highlight: The graph of fx = log_b x is the reflection of gx = b^x in the line y = x.
The lesson then moves on to graphing transformed logarithmic functions. It provides an example of graphing fx = log_3x−1 and explains the steps involved.
Example: Given y = a logx−h + k, the vertical asymptote is at x = h
Students are then given an opportunity to practice graphing a transformed logarithmic function:
Example: Graph fx = -log_2 x - 1
The lesson concludes with a formative assessment, asking students to rewrite and graph y = log_2 x - 1.
Vocabulary: Transformation - a change in the shape, size, or position of a graph
This comprehensive lesson provides students with a solid foundation in logarithmic function graphs, their relationship to exponential functions, and how to apply transformations to these graphs.