There are many.
Trigonometry is a whole branch of mathematics and does not comprise only one formula!
Beacause with a formula you are finding out a problem. Just like evaluating means to find out or to solve.
The answer depends on what other information is available to you.
moivre's formula
The answer depends on what other information is available to you.
Trigonometry is a whole branch of mathematics and does not comprise only one formula!
No, because trigonometry is a big subject: there are many formulae.
Beacause with a formula you are finding out a problem. Just like evaluating means to find out or to solve.
The answer depends on what other information is available to you.
moivre's formula
The answer depends on what other information is available to you.
formula expression
Trigonometry is basically formula's to help you find out unknown sides and angles of a triangle. Surveying is measuring land. But as not all land is equal so these formula's are used to help.
The general term is trigonometry. What specific formula you use depends on what other information you have.
plane trigonometry spherical trigonometry
The main kinds are plane trigonometry and solid trigonometry. The latter will include trigonometry in hyper-spaces.
It is a number - in trigonometry or elsewhere.