Is cos(z+w)=cos(z)cos(w)-sin(z)sin(w) ?

The answer to whether cos(z+w)=cos(z)cos(w)-sin(z)sin(w) is True

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prove cos(z+w)=cos(z)cos(w)-sin(z)sin(w)

prove

cos (z + w) = cos (z) cos (w) - sin (z) sin (w)

True

Solution steps

cos (z + w) = cos (z) cos (w) - sin (z) sin (w)

Use the Angle Sum identity:

cos (s + t) = cos (s) cos (t) - sin (s) sin (t)

\Rightarrow True

(1 - cos^{2} (θ)) csc^{2} (θ) = 1

tan (π - θ) = - tan (θ)

(cot (θ) + tan (θ)) cos (θ) = csc (θ)

tan (x + \frac{π}{4}) = \frac{1 + tan ( x )}{1 - tan ( x )}

\frac{cos ^{2} ( x )}{1 + sin ( x )} = 1 - \frac{1}{csc ( x )}

Is cos(z+w)=cos(z)cos(w)-sin(z)sin(w) ?
The answer to whether cos(z+w)=cos(z)cos(w)-sin(z)sin(w) is True