1. Warm Up 1)Are the following functions periodic? 2) Write the equation of a cosine function given the following information: Amplitude = 5, Period = π, Phase shift 2π units left, Vertical shift up 2 units and a reflection over the x axis.

2. Reminder!! Tomorrow go to room 1608 for 2 nd period!

3. HW Check

5. Arc Length An arc of a circle is a portion of the circumference formed by a central angle. It’s the length of the pie crust! θ

6. Arc Length The arc length s of a circle radius r, subtended by a central angle of θ radians, is given by: s = rθ The angle must ALWAYS BE IN RADIANS. Sometimes it will be given in degrees to trick you. Convert it to radians!

7. Find the length of the arc of a circle of radius 4 meters subtended by a central angle of 0.5 radian. Example 1: Arc Length “Subtended?” That just means “formed by.”

8. Area of a Sector A sector of a circle is a portion of the circle formed by a central angle. It’s the area of a slice of pie! θ

9. Area of a Sector The area of a sector A of a circle radius r, subtended by a central angle of θ radians, is given by: A = ½r 2 θ Again, the angle must ALWAYS BE IN RADIANS. Sometimes it will be given in degrees to trick you. Convert it to radians!

10. Find the area of the sector of a circle of radius 5 feet subtended by an angle of 60°. Round the answer to two decimal places. Example 2: Area of a Sector “Subtended?” That just means “formed by.”

11. Put it all together! Arc Length Area of a Sector s = rθ A = ½r 2 θ Length of pie crust Area of a slice

12. Unit 4 Review Sheet