### Present Remotely

Send the link below via email or IM

• Invited audience members will follow you as you navigate and present
• People invited to a presentation do not need a Prezi account
• This link expires 10 minutes after you close the presentation

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.

# 6.4 Graphs of Sine and Cosine Functions

No description
by

## Calvin Kirkpatrick

on 18 January 2014

Report abuse

#### Transcript of 6.4 Graphs of Sine and Cosine Functions

6.4 Graphs of Sine and Cosine Functions
The Sine Graph
This is the graph of
y = sin x
it is the parent graph for all sine functions.

The Cosine Graph
Need help?
Real Life Application
Electricity can flow in both an alternating current (AC) or a direct current (DC). Alternating currents are very interesting because they flow in the form of a sine wave. The AC is how electricity is delivered to house and businesses. An oscilloscope can measure oscillations of an electrical current and display it on a screen in the form of a sine graph
The parent graph has five key points: 0, π/2, π, 3π/4, and 2π.
0
This video gives the unit circle definition of the sine graph.
This video shows how to graph sine and cosine functions.
This is the graph of
y = cos x
it is the parent graph for all cosine functions.

The parent graph has five key points: 0, π/2, π, 3π/4, and 2π.
Multiple Choice Problem
Write the equation of the sine function given the characteristics.

Graphing Transformations
If
w
> 0, the amplitude and period of
y =
A
sin (
w
x) and y =
A
cos (
w
x)
are given by:
Using our knowledge of transformations
y =
3
sin (
2
x)
has an amplitude of
3
and a period of
π
.
Amplitude = I
A
I Period = T = 2π/
w

Amplitude: 3
Period: 2
A. y = 3 sin (2x)
B. y = ±4 sin (πx)
C. y = ±3 sin (πx)
D. y = 4 sin (2x)
C. y = ±3 sin (πx)
Free Response Problem
Graph the function
Solution
y = 2 sin (.5x)
Solution
Amplitude:
3
Period:
2
y = I
A
I sin (
w
x)
y = I
3
I sin (
π
x)
y = ±
3
sin (
π
x)

Remember
Period = 2π/
w
2 = 2π/
w
2
w
= 2π

w
= 2π/2
w
= π
First we have our parent graph y = sin x.
Then we change the parent graphs amplitude to
2
because our function was y =
2
sin (.5x).
Finally we adjust the period. The period is 4π because our function was
y = 2 sin (
.5
X).
Remember Period = T = 2π/
w
T = 2π/
.5
T = 4π
Theorem
Oscilloscope
More Practice
Page 407-409
Questions 27,35,65,73
Chinese Spouting Bowl
The Chinese Spouting Bowl was created during the Han Dynasty in ancient China. By rubbing ones hands on the handles a skilled person can make waves jump out of the bowl at up to three feet high.
It works by using sine graphs. Rubbing the handle of the bowl creates vibrations and in turn the vibrations create nodes and anti nodes. A node is a place of no displacement and and anti node is the opposite.
Two sine waves are created because there are two handles. The sine waves collide and create spouts of water. The following video explains the phenomenon pretty well.
Full transcript