1. The document provides instructions for determining the parameters a, b, and c of sine and cosine functions given a graph. 2. To find a, subtract the high and low values and divide by 2, making a negative if the graph is upside down. 3. To find b, observe the length of one wave which is the period. 4. To find c, observe the location of the wrap line and c equals the height of this line. Examples are then worked through to apply these instructions.

1. Homework: Worksheet 10­5
1. y = ­4 2. y = 2 3. y = 6 4. y = ­3 5. y = 0
6. 7. 8.
b = 1 π
π
2π
b = 2
b = 2
9. 10.
4π
b = π/4
8
b = 1/2

2. Copy this to the back of HW 10­5.
Lsn 10­6: Given a Graph of a sin or cos function, determine
a, b, and c.
1. To find "a": subtract high and low and divide by 2.
make "a" negative if the graph is upside down.
2. To find "b": observe length of one wave (period).
3. To find "c": observe location of wrap line y = c
c = height of wrap line

5. ex. 1: sine or cosine?
a > 0 or a < 0 ?
period =
=
wrap line y =
c =

6. ex. 2: sine or cosine?
a > 0 or a < 0 ?
period =
=
wrap line y =
c =

7. ex. 3: sine or cosine?
a > 0 or a < 0 ?
period =
=
wrap line y =
c =