Is cos^3(A)= 1/4 (cos(3A)+3cos(A)) ?

The answer to whether cos^3(A)= 1/4 (cos(3A)+3cos(A)) is True

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prove cos^3(A)= 1/4 (cos(3A)+3cos(A))

prove

cos^{3} (A) = \frac{1}{4} (cos (3 A) + 3 cos (A))

True

Solution steps

cos^{3} (A) = \frac{1}{4} (cos (3 A) + 3 cos (A))

Manipulating right side

\frac{1}{4} (cos (3 A) + 3 cos (A))

Rewrite using trig identities

= cos^{3} (A)

We showed that the two sides could take the same form

\Rightarrow True

sin (x) = - \frac{1}{2}

\frac{1}{sin ( x ) + 1} + \frac{1}{csc ( + 1 )} = 1

cos (x) = sin (x - π)

cos (φ + a) - cos (φ - a) = - 2 sin (φ) sin (a)

(1 - cos (θ)) (1 - cos (θ)) = \frac{1}{csc ^{2} ( θ )}

Is cos^3(A)= 1/4 (cos(3A)+3cos(A)) ?
The answer to whether cos^3(A)= 1/4 (cos(3A)+3cos(A)) is True