Basic Trigonometry - Key Facts
You must be familiar with the: sine rule: cosine rule:
Trigonometric Equations - Key Facts
You must be familiar with the identities and . A trigonometric equation of the form has many solutions:
- a principal solution, ie. - the one you get from your calculator;
- an alternate solution, ie. - as cos has two solutions in each 360°;
- an infinite number of repeat solutions from , since cos repeats every 360°.