The Six Compound Angle Identities
Double Angle Formulae
Factor Formulae
rcos() form
Adding a sine and a cosine will generate a cosine curve. This will have a larger amplitude than the original and is out of phase with it.
Writing the expression as rcos(θ - α),
'r' amplitude
'α' no. degrees phase difference(to the right)
Thus expressions of the form:
can be rewritten as
Finding 'r' and the phase angle 'α'
