That means the same as solutions of other types of equations: a number that, when you replace the variable by that number, will make the equation true.Note that many trigonometric equations have infinitely many solutions. This is a result of the trigonometric functions being periodic.

There are no universal rules. However, there are a number of situations : quadratic functions and their square roots for which trigonometric substitutions are effective.

There are three types of trigonometric functions, they are:

1- Plane Trigonometric Functions

2- Inverse Trigonometric Functions and

3- Hyperbolic Trigonometric Functions

There are a huge number of arithmetic, algebraic and trigonometric operators.

It is a trigonometric function whose argument is the number theta.