4.1b Radian and Degree Measure.notebook
WARM UP
Define in your own words:
• Degree
• Radian
• Coterminal angles
• Complementary angles
• Supplementary angles
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8­22­14
4.1b Radian and Degree Measure.notebook
August 22, 2014
Q: How many degrees is radians?
A:
How many radians is 1 ?
To convert from degrees to radians:
How many degrees is rad?
To convert from radians to degrees:
4.1b Radian and Degree Measure.notebook
Example
(a) Convert ­270 degrees to radians.
(b) Convert radians to degrees.
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4.1b Radian and Degree Measure.notebook
Old school stuff...
August 22, 2014
4.1b Radian and Degree Measure.notebook
August 22, 2014
Arc Length
Example 5, p. 263
A circle has a radius of 4 inches. Find the length of the arc intercepted by a central angle of 240 degrees, as shown in Fig. 4.15.
p. 266: #71 (HW)
4.1b Radian and Degree Measure.notebook
August 22, 2014
Find the distance (length!) between the cities. Assume Earth is a sphere of radius 4000 miles and the cities are on a the same longitude (one city is due north of the other city).
San Francisco
Seattle
N
N
4.1b Radian and Degree Measure.notebook
August 22, 2014
HOMEWORK
...can you switch from degrees to radians and think like a mature
mathematician?
4.1: pg. 266: 39 ­ 75odd, 76, 77­85eoo, 89, 91, 93