2 

1. (0,1) x = 1 Radian  0  (1,0) (-1,0) 2 (1,0) (0,-1) 57.3 1 Radian = x x = 1 Radian  180   1 Radian x = 57.3 Radius 1 Radian is defined as the angle that intersects an arc having the same length as the radius of that circle. It measures approximately 57.3.

2. radius   1 radian 1 radian = = = 57.3 57.3 = 2 radii 3 radii 1 radius 0.28 radii 4 radii 6 radii 5 radii 360 = 2 radians  6.28 radians(radii) 2 radians= 360  radians= 180

3. 2 radiansrepresents 360. Angles can be measured with either degrees or radians. If you wish to use any trigonometric functions on your calculator, you must ensure that your calculator is in the mode that you intend to use (either degrees or radians). For must functions on your calculator it doesn’t matter but for trigonometric functions (sin, cos or tan), it does. Why do we use multiples of π with radians? Because it can be very convenient. Many common angles can be easily represented as a simple multiple of π radians. Remember that π in no way implies that radians are the units. π can be used with degrees as well. It is just that it is not as convenient. Also π is not always used with radians.

4. Use your calculator to determine the ratios of the following: sin 30 =-0.9880 sin 2π = 0 cos π = -1 cos 1 = 0.5403 tan 1.5π = undefined sin 2 = 0.9093 sin 1.57 = 1.0000 cos 3.14 = -1.0000 sin 4.71 = -1.0000 tan 1.75π = -1 sin 30º =0.5 sin 30πº =0.9973 cos 45º =0.7071 tan 78º =4.7046