The Six Trigonometric Functions

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The Six Trigonometric Functions
DateTopic Right Triangle Trigonometry (4.3)
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Right Triangle Definitions of Trigonometric
Functions
SohCahToa
Hyp
Opp
?
Adj
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Example
A
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Sines, Cosines, and Tangents of Special Angles
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Complete Student Checkpoint
Find the value of each of the six trig functions
of in the figure.
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Cofunction Identities

• The value of a trigonometric function of ? is
  equal to the cofunction of the complement of ?.
• sin ? cos (90º ?) cos ? sin (90º ?)
• tan ? cot (90º ?) cot ? tan (90º ?)
• csc ? sec (90º ?) sec ? csc (90º ?)
• If ? is in radians, replace 90º with ?/2.

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Complete Student Checkpoint
Find a cofunction with the same value as the
given expression. a. sin 46º b. cot
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Text Example
Sighting the top of a building, a surveyor
measured the angle of elevation to be 22º. The
transit is 5 feet above the ground and 300 feet
from the building. Find the buildings height.
The height of the part of the building above the
transit is approximately 121 feet. If we add the
height of the transit, 5 feet, the buildings
height is approximately 126 feet.
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Complete Student Checkpoint
The distance across the lake, a, is unknown. To
find this distance, a surveyor took the
measurements shown in the figure. What is the
distance across the lake?
The distance across the lake is approximately
334 yards.
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Right Triangle Trigonometry