Lösung 4.2:8
Aus Online Mathematik Brückenkurs 1
We start by drawing three auxiliary triangles, and calling the three vertical sides x, y and z, as shown in the figure.
Using the definition of cosine, we can work out x and y from
and, for the same reason, we know that z satisfies the relation
In addition, we know that the lengths x, y and z satisfy the equality
If we substitute in the expressions for x, y and z, we obtain the trigonometric equation
where \displaystyle \gamma is the only unknown.
