Frequently Asked Questions
Trigonometrical functions are functions that relate an angle to ratios of sides of a right-angled triangle or to coordinates on the unit circle
Because each angle corresponds to a unique real value of sine, cosine, tangent, etc
An angle measured in radians can take any real value, positive or negative
Radian is the angle subtended at the center of a circle by an arc equal in length to the radius
There are p radians in 180 degrees
The domain of sin x and cos x is all real numbers
The range is from -1 to 1 inclusive
All real numbers except odd multiples of \(\pi/2\)
Periodicity means the function repeats its values after a fixed interval
The period is \(2\pi\)
The period is \(\pi)
Identities that hold true for all permissible values of \(x\), such as \(\sin^2 x + \cos^2 x = 1\)
Identities that relate trigonometric functions as reciprocals of each other
Identities expressing tan x and cot x as ratios of sine and cosine
Identities derived from the Pythagorean theorem involving sin, cos, and tan