Question

( cos x + i sin x ) * ( cos x - i sin x ) wieso gibt das 1 ?

Answer 1

(a + b) * (a - b) = a^2 - b^2

(cos(x) + i*sin(x)) * (cos(x) - i*sin(x)) = cos^2(x) - i^2*sin^2(x) = cos^2(x) + sin^2(x) = 1