Chapter 5 Radians (Year 2) Flashcards
What is 360 degrees in radians?
2 pi
What is 180 degrees in radians?
Pi radians
What is 1 radian in degrees?
180/pi degrees
What is 30 degrees in radians?
Pi/6
What is 60 degrees in radians?
Pi/3
What is 45 degrees in radians?
Pi/4
What is 90 degrees in radians?
Pi/2
What is sin(pi/6)?
1/2
What is sin(pi/3)?
Sqrt3/2
What is sin(pi/4)?
Sqrt2/2
What is cos(pi/6)?
Sqrt3/2
What is cos(pi/3)?
1/2
What is cos(pi/4)?
Sqrt2/2
What is tan(pi/6)?
Sqrt3/3
What is tan(pi/3)?
Sqrt3
What is tan(pi/4)?
1
What is sintheta equivalent to?
- Sin(pi - theta)
- sin(pi + theta)
- sin(2pi - theta)
What is costheta equivalent to?
- cos(pi - theta)
- cos(pi + theta)
- Cos(2pi - theta)
What is tantheta equivalent to?
- tan(pi - theta)
- Tan(pi + theta)
- tan(2pi - theta)
How do you find the arc length l of a circle?
Use the formula l = r theta (r is the radius and theta is the angle in radians)
How do you find the area of a sector?
Use the formula A = 1/2 r^2 theta (r is the radius and theta is the angle in radians)
How do you find the area of a segment in a circle?
A = 1/2 r^2 (theta - sintheta) (r is the radius and theta is the angle in radians)
What are the small angle approximations?
Sin theta = theta
Tan theta = theta
Cos theta = 1 - theta^2/2
