Lösung 4.3:3d
Aus Online Mathematik Brückenkurs 1
The expression for the angle \displaystyle \pi/2 - v differs from \displaystyle \pi/2 by as much as \displaystyle -v differs from \displaystyle 0. This means that \displaystyle \pi/2-v makes the same angle with the positive y-axis as \displaystyle -v makes with the positive x-axis.
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| Angle v | Angle π/2 - v |
Therefore, the angle \displaystyle \pi/2 - v has a y-coordinate which is equal to the x-coordinate for the angle v, i.e.
and from exercise c, we know that \displaystyle \cos v = \sqrt{1-a^2}\,,
