PreCalculus: Lesson Plan * 8/28/2006

• Quickstart Algebra I Workbook p.145 #1-25, no calculator
• Lesson
  (4.5) Graphs of Sine and Cosine Functions
  
  1. Exploration with Graphing Calculators
     Graph y = sinx, y = 4 sinx, and y = sin(2x)
     Notice similarities and differences.
     Where are the intercepts, max, and min?
     What is the period, the distance on the x-axis until the graph repeats?
     What is the amplitude, the "height" of the graph?
     
  2. Amplitude and Period (p.325 - 326)
     
     • Amplitude = |a|
       y = a sinx
       vertical stretching when |a| > 1
       vertical shrinking when 0 < |a| < 1
       changes the y-coordinate of the minimum and maximum
       intercepts remain the same
       
     • Period = 2π/b
       y = sin( bx )
       horizontal stretching when 0 < b < 1
       horizontal shrinking when 1 < b
       changes the x-coordinate of the minimum and maximum and the intercepts
     • Find the amplitude and the period of y = -4cos(3x)
       Amplitude = |a| = |-4| = 4
       Period = 2π/b = 2π/3
       
• Homework
  p. 330 - 331 #1 - 12 x 3's