Algebra 3
Section 8.2
Reminder:
Chapter 8
Section 2 notes
A = max - min
SINE AND COSINE CURVES
Remember...
cf(x) vertical stretch/shrink
f(cx) horizontal stretch/shrink
Graph
y = sin x
P=
A=
y = 2sin x
P=
A=
Graph is based on the unit circle:
At 0o, y = 0
(0o,0)
x-axis
At 90 , y = 1 degree/radian
measure
(90o, 1)
o
At 180o, y = 0
(180o, 0)
Remember...
cf(x) vertical stretch/shrink
f(cx) horizontal stretch/shrink
Graph
y = cos x
P=
A=
y = -1/2 cos x
P=
2
A=
Algebra 3
Section 8.2
Remember...
cf(x) vertical stretch/shrink
f(cx) horizontal stretch/shrink
Graph
y = sin x
P=
y = sin 2x
A=
Period and Amplitude
y = A sin (Bx)
A≠ 0
y = A cos (Bx)
B>0
P=
A=
Amplitude = ΙAΙ
Period = 2π or 360
B
B
ο
Example
Find the period and amplitude. Sketch at least one period.
y = 3 sin ( / x)
1
2
Algebra 3
Section 8.2
Example
Write the equation of the trig function being described.
A sine curve varies between 3 and -3 with a period of π/6.
Homework
pg. 305 #1 - 17
odds or all, you decide :-)