If sin α = 0.865 and cos β = 0.272 with both angles’ terminal rays in Quadrant 1, find the values of (a) sin ( α + β ) = and (b) cos ( α − β ) =

Answer 1

Hi Matthew B.,

there are identities for such forms. Google the expressions to check them out, maybe even memorize the forms.

-- Cheers, --Mr. d.