section 131: right triangle trigonometry · 2010-04-19 · section 131: right triangle...
TRANSCRIPT
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Apr 1610:07 PM
Welcome to Trigonometry!
Trigonometry is the study of triangles. We will spend quite a bit of time in Chapter 13 revisiting and deepening our understanding of right triangle
trigonometry.
Later in the chapter, we will explore relationships of all triangles.
In Chapter 14, we will use what we have learned in Chapter 13 to solve trigonometric equations.
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Section 131: Right Triangle Trigonometry
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Ratios of a right triangle's three sides are used to define six trigonometric functions. Here are the first three:
(Hint: Do you remember SOHCAHTOA?)
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The first three trigonometric ratios should have been a review from geometry. The last 3 may be new to you. However, they are simply reciprocals of the Sine,
Cosine and Tangent ratios. So, you may need to study their names, but if you know SOHCAHTOA, it
shouldn't be too hard to learn!
or
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A Ratio is a comparison of two items.
For instance, what is the ratio of boys to girls in the class?
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S SineO Opposite Leg (over)H Hypotenuse
C CosineA Adjacent Leg (over)H Hypotenuse
T TangentO Opposite Leg (over)A Adjacent Leg
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Now, let's use this information to try an example:
Ex. 1:
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Ex. 2: Let θ be an acute angle of a right triangle. Find the values of the other five trigonometric functions of θ.
csc θ = 107
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Learning Opportunity #1:
p. 856 #315 odd, 16
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Ex. 3: Solving a Triangle
Let's resolve calculator issues.
a. Make sure you are in the proper mode (radian vs. degree.)
b. How do you enter in the reciprocal functions?
sin 40 cos 40 tan 40
csc 40 sec 40 cot 40
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c. Template to set up the following problems:
AngleMeasurement =
TrigFunction
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Learning Opportunity #2:
p. 8568 #1727 odd
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Ex. 4: Application Problem
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Ex. 5: Application Problem
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Ex. 5: A parasailer is attached to a boat with a rope 300 feet long. The angle of elevation from the boat to the parasailer is 48. Estimate the parasailer's height above the boat.
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Learning Opportunity #3:p. 857 #3032
Worksheet 131 Apps #110
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