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Angles and Radian Measure. Alg ll/Trig – Trig Ch C day 2. Notice that the graphs of sine, cosine and tangent repeat. Because these functions “repeat” we say they are __________ Sine repeats every ____ . Sine has a ________of _____
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Angles and Radian Measure Alg ll/Trig – Trig Ch C day 2
Notice that the graphs of sine, cosine and tangent repeat. Because these functions “repeat” we say they are __________ Sine repeats every ____. Sine has a ________of _____ Cosine repeats every ____. Cosine has a _______ of ____ Tangent repeats every ____. Tangent has a ________ of ____ Find the period for each of the following functions: PERIODIC 360 PERIOD 360 360 PERIOD 360 PERIOD 180 180 y = sec xy = csc x y = cot x 360 180 360
Radian Measure Consider an angle such that its vertex is at the center of a circle. Let r= _________ and S be the _________ of the arc created by the angle . We will no longer measure angles in __________. They will now be measured in ________ defined as such: RADIUS LENGTH DEGREES RADIANS In other words, is the number of _______that make up the ______ that creates. This means that the radian measure of an angle is simply a __________ of the _________________ of the circle. RADII ARC FRACTION CIRCUMFERENCE
1 Revolution: ¾ Revolution:
½ Revolution: ¼ Revolution:
Conversion Formulas: Radians Degrees: Degrees Radians: Multiply by ___________ Multiply by ___________ Change in degrees Change 32 into radians.
What is the formula for the rate (or speed) at which an object is moving? Linear Speed When an object is moving at a constant speed in a ____________ path with a radius of, r, the linear speed of the object is given by _______________, which is just ________________. Angular Speed The angular speed of the object is the measure of how ______ the _______ of _________ for the object _________ and is given by _________, where is an angle measure in ________ and t is _______. CIRCULAR FAST ROTATION ANGLE CHANGES RADIANS TIME
Example 3: A weather satellite orbits the Earth at an altitude of approximately 22,200 miles above Earth’s surface. The radius of the Earth is 3960 miles. If the satellite observes a fixed region on Earth and has a period of revolution of 24 hours, what is the linear speed of the satellite? What is its angular speed? linear speed angular speed satellite Earth Time: 24 hours Radius: 26,160 miles 3960 + 22,200 LINEAR SPEED: ANGULAR SPEED:
( , ) (0 , 1) ( , ) 90 ( , ) ( , ) ( , ) 120 60 ( , ) 135 45 150 30 (-1, 0) (1, 0) 0 180 360 210 330 225 315 ( , ) 240 300 ( , ) ( , ) ( , ) ( , ) 270 ( , ) (0, -1)