Sketching a Sinusoidal Graph

   • First identify:

       Median line (d)
       Maximum value (d+a)
       Minimum value (d-a)
       Period (2л/b)
       Start point (-c,d) or (-c/b,d) if b is in the bracket

   • Draw the median line on the graph.
   • Mark a point on the graph at the start point.
   • Mark another point on the graph at the end point, which will be the
     start point plus the length of the period.
   • Divide the horizontal axis into 4 equal sections beginning at the start
     point and finishing at the end point.
   • Mark a point on the median line half way between the start point and
     the end point.
   • Mark a maximum point between the start point and the half way point.
   • Mark a minimum point between the half way point and the end point.
   • Join the points with a smooth curve.

   Example:

   Sketch y = 4 sin 2 (x -л) - 2

Assignment:

Sketch the following graphs:


          a. y = 2 sin (x - л/2) - 1
          b. y = sin 2л x
          c. y = -3 sin (2x + л/3)

Sketching a sinusoidal graph

  • 1.
    Sketching a SinusoidalGraph • First identify: Median line (d) Maximum value (d+a) Minimum value (d-a) Period (2л/b) Start point (-c,d) or (-c/b,d) if b is in the bracket • Draw the median line on the graph. • Mark a point on the graph at the start point. • Mark another point on the graph at the end point, which will be the start point plus the length of the period. • Divide the horizontal axis into 4 equal sections beginning at the start point and finishing at the end point. • Mark a point on the median line half way between the start point and the end point. • Mark a maximum point between the start point and the half way point. • Mark a minimum point between the half way point and the end point. • Join the points with a smooth curve. Example: Sketch y = 4 sin 2 (x -л) - 2 Assignment: Sketch the following graphs: a. y = 2 sin (x - л/2) - 1 b. y = sin 2л x c. y = -3 sin (2x + л/3)