Compound angle formulae
Posted in Maths, Core 4There are 6 compound-angle formulae you need to be aware of. Depending on your exam board you may or may not be required to remember these as they may be in your formula books.
Where and
are just any angle.
These can be used to expand and simplify expressions involving trigonometric functions.
Double angle formulae
By substituting into the compound formulae gives expressions for
,
and
:
Example usage
These can be used to solve equations involving trigonometric functions.
Example question: Find the smallest value of , such that
Worked solution: Firstly use the above relation for and substitute it into the equation:
Divide both sides by to elimate it the from the equation:
Divide by 4...