Lösung 4.3:6a
Aus Online Mathematik Brückenkurs 1
If we think of the angle v as an angle in the unit circle, then v lies in the fourth quadrant and has x-coordinate 3/4.
If we enlarge the fourth quadrant, we see that we can make a right-angled triangle with hypotenuse equal to 1 and an opposite side equal to 3/4.
Using the Pythagorean theorem, it is possible to determine the remaining side from
which gives that
Because the angle v belongs to the fourth quadrant, its y-coordinate is negative and is therefore equal to \displaystyle -b, i.e.
Thus, we have directly that
