Logarithmic function. Properties.

This book contains the lesson project that introduces the logarithmic function and discovers the properties of this function.

  • Subject: Mathematics
  • Grade Level: 10th grade
  • Duration: about 50 min
  • Technology setting: Computer and projector for teacher, computers/ tablets for students.

Topic.

Logarithmic function. Properties. The geometric representation of the graph of the logarithmic base function supraunitary and subunitary, identification of its inversion by right symmetry y = x (first bisector), solving some equations.

Learning Outcomes

During the lesson, students:
  • will discover the graph of the logarithmic function with a supraunit and subunit base;
  • will see, through graphical reading, the properties of the functions: monotony, convexity, infinite variation (slope) ...
  • will explore the sign of the logarithmic function;
  • will identify the exponential function as the inverse logarithmic function.
After the lesson,students will know :
  • the properties of the logarithmic function in relation to the base;
  • students will know how to compare the logarithm of the same number in relation to the base;
  • that the logarithmic function is inverse to the exponential function.
As a result of the lesson,students will be able to do it :
  • to plot the logarithmic function graph;
  • to compare two logarithms;
  • to resolve some of the equations graphically.

Lesson Objectives and Assessment

Lesson objectives:
  • students can draw through points the graph of the logarithmic function;
  • students can explain the properties of the logarithmic function;
  • in relation to the base, can distinguish the differences between properties;
  • identifies the inverse logarithmic function;
  • can explain inequalities between logarithms;
  • can read from the graph the sign of the logarithmic function.
Assessment:
  • check the students' written notes;
  • in applet 2, changing the logarithm base, students are required to observe the properties and list them;
  • discussions about the power of infinite convergence of the logarithm with the help of the tangent slope to the graph.
Prior Knowledge:
  • students need to be familiar with identifying the properties of a graphical reading function;
  • students need to know the graph of the exponential function;
  • students need to know the relationship between the function graphs and .

Teaching Strategies

Methods and strategies:
  • learning by discovery;
  • questioning;
  • conversation, observation.
Equipment:
  • Computer and projector for teacher;
  • computers/ tablets for students.

Technology Integration

  • Students need to be familiar with identifying the properties of a graphical reading function; to know the graph of the exponential function; to know the relationship between the function graphs and .
  • In order to have no problems, before the lesson I will ensure that all pupils have their applets downloaded on their equipment.