Mark M. answered 11/17/20
Retired math prof. Very extensive Precalculus tutoring experience.
cos2θ - sin2θ = cos(2θ)
So, cos2(27°) - sin2(27°) = cos54° and cos2(7x) - sin2(7x) = cos(14x)
Sara S.
asked 11/17/20Using a double-angle or half-angle formula to simplify the given expressions.
(a) If cos2(27∘)−sin2(27∘)=cos(A∘),
thenA= degrees.
(b) If cos2(7x)−sin2(7x)=cos(B),
thenB= .
Mark M. answered 11/17/20
Retired math prof. Very extensive Precalculus tutoring experience.
cos2θ - sin2θ = cos(2θ)
So, cos2(27°) - sin2(27°) = cos54° and cos2(7x) - sin2(7x) = cos(14x)
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