Writing Equations of Trig Graphs

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 =