MATHEMATICS S5 UNIT 5: Trigonometric Functions and Their Inverses.
About Course
Trigonometric functions and their inverses are fundamental concepts in mathematics, particularly in pre-calculus, calculus, and their applications in science and engineering. They describe relationships between angles and side lengths of triangles, and extend to represent periodic phenomena.
1. Trigonometric Functions (The Six Basic Functions)
Trigonometric functions are functions of an angle. They are most commonly defined using either the unit circle or right-angled triangles.




2. Inverse Trigonometric Functions (Arc Functions)
Inverse trigonometric functions are used to find the angle when the value of a trigonometric ratio is known. They “undo” the action of the original trigonometric functions.
The Challenge of Inverses and Domain Restriction:
Standard trigonometric functions are not one-to-one (they fail the horizontal line test) because they are periodic. For an inverse function to exist, the original function must be one-to-one. Therefore, to define inverse trigonometric functions, we must restrict the domain of the original trigonometric functions to an interval where they are one-to-one and cover their full range. This restricted interval is called the principal value range.





Course Content
Generalities on Trigonometric Functions and Their Inverses.
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Domain and Range of Six Trigonometric Functions.
14:59 -
Domain and Range of Inverses of Trigonometric Functions.
19:38 -
Party of Trigonometric Functions.
18:49