Question

Wieso gelten diese drei Gleichungen nicht?

(1) sin (alpha+ beta) = sin(alpha) + sin(beta)

(2) cos (alpha+beta) = cos(alpha) + sin(beta)

(3) tan (alpha+beta) = tan(alpha) + tan(beta)

Answer 1

(1) \(\sin (45°) = \frac{1}{\sqrt 2}\)

      \(\sin (45° + 45°) = \sin (90°) = 1 \neq \frac{1}{\sqrt 2}+\frac{1}{\sqrt 2}\)

(2) \(\cos (0°) = 1\)

      \(\cos (0° + 0°) = \cos (0°) = 1\neq 1+1\)