Trigonometry Functions of Any Angle

The definition of trigonometric functions were restricted to acute angles . Here, the definition will be extended to cover any angle.

Let o be an angle in standard position with (x, y) a point on the terminal side of o and r = √x² + y² ≠ 0

Because r = √x² + y² cannot be zero, it follows that the sine and cosine functions are defined for any real value of . However, if x = 0, the tangent and secant of o  are undefined. For example the tangent of is undefined. Similarly, if y = 0, the cotangent and cosecant of are undefined.

 

Learn more about the trigonometric functions of any angle by reading the explanation below.

Trigonometry Functions of Any Angle


Practice: Evaluate the trigonometric functions of any angle and of real numbers in the following exercises.

Trigonometry Functions of Any Angle 1

Trigonometry Functions of Any Angle 2

Trigonometry Functions of Any Angle 3