Radius

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
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? radians represents 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 doesnt matter but for
trigonometric functions (sin, cos or tan), it
does.
Why do we use multiples of p with radians?
Because it can be very convenient. Many common
angles can be easily represented as a simple
multiple of p radians. Remember that p in no way
implies that radians are the units. p can be
used with degrees as well. It is just that it is
not as convenient. Also p is not always used
with radians.
4
Use your calculator to determine the ratios of
the following
sin 30 -0.9880 sin 2p 0 cos p -1 cos 1
0.5403 tan 1.5p undefined sin 2 0.9093 sin
1.57 1.0000 cos 3.14 -1.0000 sin 4.71
-1.0000 tan 1.75p -1
sin 30º 0.5 sin 30pº 0.9973 cos 45º
0.7071 tan 78º 4.7046