Lösung 4.3:4f
Aus Online Mathematik Brückenkurs 1
Using the addition formula for cosine, we can express \displaystyle \cos (v-\pi/3) in terms of \displaystyle \cos v and \displaystyle \sin v,
Since \displaystyle \cos v = b and \displaystyle \sin v = \sqrt{1-b^2} we obtain