An angle consists of two rays, R1 and R2, with a common vertex.
Standard position of an angle:
An angle is said to be in standard position if its vertex is at the origin of a rectangular coordinate system and its initial side coincides with the positive x-axis.
Two angles in standard position are said to be co-terminal if they have the same initial and terminal sides.
For a circle of radius , a central angle of radius subtends and arc whose length is
is measured in radians.
Area of a sector:
The area of the sector of a circle of radius formed by a central angle radians is
where the unit of angle must be in radians.
Linear speed: The linear speed is defined as .
Angular speed: The angular speed is defined as .
The domain of the sine function:
The domain of the sine function is the set of all real numbers.
The domain of the cosine function:
The domain of the cosine function is the set of all real numbers.
A function is called periodic if there is a positive number such that, whenever is in the domain of so is and . P is the period of
The Period of sine and cosine functions:
The period of sine and cosine functions is