Trig Identities are needed in some problems
to manipulate expressions before derivative or integrals
can be taken and to simplify answers.
You MUST know the Basic Identities.
IDENTITIES Howe-Two (Advanced )
You can practice these in the lab
Pythagorean and sum-Difference--used
Identities II to practice sum/difference
sin (a ± b) = sin a cosb ± cosa sinb cos (a ± b) = cos a cosb sina sinb
sin(2a)=2 sin a cos a cos (2a) = cos2 a - sin2 a cos (2a) = 2cos2 a - 1 cos (2a) = 1 - 2 sin2 a
|
You also need to know odd-even identities and phase shift.sin(x)= - sun(-x) cos(x)=cos(-x) cos (x-p/2) = sin (x) cos(x +p/2) = -sin(x)