Training Camp (cont 3)

In mathematics, physical quantities can be measured in various units and systems of measure. For example, length can be measured in metres or yards, volume can be measured in litres or gallons, and mass can be measured in kilograms or pounds.

Sinusoidal functions are often used to analyze periodic data that relates to angles. There are two commonly used units of measure for angles. The more familiar unit is degree. The second unit is called the radian. It is important to understand how radians and degrees relate as you study sinusoidal functions.

	Degrees are determined by dividing a circle into 360 equal parts. Radians are similiarly produced, except a full circle has 2π radians.

In most branches of mathematics beyond practical geometry, angles are universally measured in radians. This is because radians have a mathematical naturalness that simplifies work with angles and periodic functions such as the sinusoidal function. When working with angles, realize that any angle measure given without a degree symbol is assumed to be in radians.