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5.3 & 5.4 Values of Trig Functions_JB.notebook 1 May 14, 2014 May 1612:50 PM 5.3 & 5.4 1. Reference Angles (5.4) 2. Basic Graphs (5.3) 3. Periodic Functions (5.3) 4. Some More Identities (5.3) 5. Variations (5.3) 6. Equations and Inequalities (5.3) 7. Inverse Functions (5.4) May 612:18 PM KNOW DO

5.3 & 5.4 Values of Trig Functions JB.notebook

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5.3 & 5.4 Values of Trig Functions_JB.notebook1
May 16­12:50 PM
5.3 & 5.4 1. Reference Angles (5.4) 2. Basic Graphs (5.3) 3. Periodic Functions (5.3) 4. Some More Identities (5.3) 5. Variations (5.3) 6. Equations and Inequalities 
(5.3) 7. Inverse Functions (5.4)
May 6­12:18 PM
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May 6­12:19 PM
5.3 & 5.4 Values of Trig Functions_JB.notebook
3
May 6­12:19 PM
Reference angles  allow us to ... • know some trig values outside of        0 < θ < π/2
• write equivalent statements that may be  useful substitutions
May 6­12:19 PM
Find the exact values of sine, cosine,  and tangent for the given angle.
5.3 & 5.4 Values of Trig Functions_JB.notebook
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May 6­12:19 PM
Find the exact values of sine, cosine,  and tangent for the given angle.
May 6­12:19 PM
sin 75o = 
5
May 6­12:19 PM
We can use reference angles to help  us (finally) make the graphs of the 
trigonometric functions.
Definition of a Periodic Function
5.3 & 5.4 Values of Trig Functions_JB.notebook
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Warm-up: Complete Worksheet (Trig. Functions - Sine and Cosine)
Then answer the same questions about the other 4 trig functions.... i.e. y=tan(x) even, odd, or neither - explain
(tangent, cotangent, cosecant, secant)
May 5­7:42 AM
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If a function is even then f(-x) = f(x)
Recall the definition of odd functions:
If a function is odd then f(-x) = -f(x)
5.3 & 5.4 Values of Trig Functions_JB.notebook
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Apr 30­3:58 PM
Knowing which trig functions are even or odd, Write a statement for each property you discovered.
for example: sin(x) is odd using what we know about odd functions, then
sin(-x) = -sin(x)
In your notes complete an equation for the other 5 trig functions.
Apr 30­3:58 PM
Refer to page 396....were the equations that you wrote correct?
You will use these for the next examples and then to verify.
Remember when you verify just work vertically using only one side and try to make it match the other side of the equal sign.
5.3 & 5.4 Values of Trig Functions_JB.notebook
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Apr 30­3:41 PM
5.3­5.4  Trig Functions
For homework you completed a chart for  domain, range, asymptotes, x­intercepts,  etc.
Refer to pg 401 for a complete list        of  graph properties for the 6 trig functions...
Discuss as a group or in small groups the  items written as a formula...do you  understand each one?
Think about this as well:
Domain y = tan(x)   could be written as 
does it make sense?
can you explain it?
Apr 29­7:46 AM
5.3 & 5.4 Values of Trig Functions_JB.notebook
15
May 6­12:19 PM
Use reference angles and/or  formulas for negatives to evaluate  each expression.
May 6­12:19 PM
Use reference angles and/or  formulas for negatives to evaluate  each expression.
5.3 & 5.4 Values of Trig Functions_JB.notebook
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See next worksheet titled "Graphing Trig Functions"
Once you are done making the  graphs...you will use them to determine  values
5.3 & 5.4 Values of Trig Functions_JB.notebook
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y = sinθ
Use the approprite trig function  graph to solve each equation or  inequality on the interval  x    [2π, 2π]
draw the line y = 1/2....where  does sin intersect the line?
sin(x) = 1/2 at ­3300, ­2100, 300, 3900
May 6­12:19 PM
Use the approprite trig function  graph to solve each equation or  inequality on the interval  x    [2π, 2π]
5.3 & 5.4 Values of Trig Functions_JB.notebook
18
May 6­12:19 PM
Use the approprite trig function  graph to solve each equation or  inequality on the interval  x    [2π, 2π]
May 6­12:19 PM
Use the approprite trig function  graph to solve each equation or  inequality on the interval  x    [2π, 2π]
5.3 & 5.4 Values of Trig Functions_JB.notebook
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May 6­12:19 PM
how would the solutions have  changed if there had not been a  domain restriction in the previous  cases?
May 6­12:19 PM
• if we do not need an exact value • if the angle is not special • if the angles reference angle is not special
We typically use the calculator.
5.3 & 5.4 Values of Trig Functions_JB.notebook
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May 6­12:19 PM
If θ is an acute angle and sin θ = 0.6635,  approximate θ.
May 6­12:19 PM
Why did it need to be stated that θ  was an acute angle in the last  problem?
5.3 & 5.4 Values of Trig Functions_JB.notebook
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HOLD IT!
Trig functions are not 1to1! How can they have inverses?!?!?
Inverses
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May 6­12:19 PM
So, the solutions you get out of  the inverse trig functions on your  calculator may or may not be the  solution you want.
to do these types of problems.....I think,
What is my reference angle? 
what quadrant am I in?  
what sign is this trig function?
Your calculator may not have the correct SIGN you want
See page 412 to see what domain restrictions your calculator assumes
May 6­12:19 PM
If tan θ = 0.4623 for 0o < θ < 360o,  approximate θ to the nearest 1o.
5.3 & 5.4 Values of Trig Functions_JB.notebook
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May 6­12:19 PM
If cos θ = 0.3842 for 0 < θ < 2π,  approximate θ to the nearest 0.0001  radian.
Apr 30­4:27 PM
Monday we will review 5.3-5.3
take any questions from Thur/Fri
and Review for quiz 5.3-5.4
we will need to probably refresh on reference angles...so please review your notes.
PS since I'm not here....your graphs quiz is on Monday :)
5.3 & 5.4 Values of Trig Functions_JB.notebook
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By the end of this section you should know:
· know how values of a trig function vary as the input varies
· definition of a periodic function
· graphs of sine and cosine functions
· formulas for negatives
· the definition of a reference angle
· understand the relationship between the trigonometric functions and their inverses
· understand the limitations of the inverse trigonometric function buttons on the calculator
By the end of this section you should be able to:
· create the graphs of sine and cosine
· use the graphs of trigonometric functions to solve equations and inequalities
· complete statements of variation for the trigonometric functions
· sketch the graphs of trigonometric functions involving transformations
· solve applied problems involving trigonometric functions
· calculate the reference angle for a given angle
· sketch a reference angle on a coordinate plane
· use reference angles to evaluate trigonometric functions of a given angle
· evaluate trigonometric functions on a calculator
· use inverse trigonometric functions to calculate an angle given the value of the trigonometric function
· use reference angles to get the correct value if outside of the limits of the calculator
· solve applied problems involving reference angles
· solve applied problems involving inverse trigonometric functions
SMART Notebook
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