Lösung 4.3:1a
Aus Online Mathematik Brückenkurs 1
(Unterschied zwischen Versionen)
			  			                                                      
		          
			| K  (Lösning 4.3:1a moved to Solution 4.3:1a: Robot: moved page) | |||
| Zeile 1: | Zeile 1: | ||
| - | {{ | + | If we draw the angle  | 
| - | < | + | <math>{\pi }/{5}\;</math> | 
| + | on a unit circle, then it will have an  | ||
| + | <math>x</math> | ||
| + | -coordinate that is equal to  | ||
| + | <math>{\cos \pi }/{5}\;</math> | ||
| + | . | ||
| - | < | + | FIGURE 1  				FIGURE 2 | 
| - | {{ | + | the line  | 
| + | <math>x={\cos \pi }/{5}\;</math | ||
| + | the line  | ||
| + | <math>x={\cos \pi }/{5}\;</math> | ||
| + | |||
| + | |||
| + | In the figures, we see also that the only other angle between  | ||
| + | <math>0</math> | ||
| + | and  | ||
| + | <math>2\pi </math> | ||
| + | which has the same cosine value, i.e. same  | ||
| + | <math>x</math> | ||
| + | -coordinate, is the angle  | ||
| + | <math>v=-\frac{\pi }{5}+2\pi =\frac{9\pi }{5}</math> | ||
| + | on the opposite side of the  | ||
| + | <math>x</math> | ||
| + | -axis. | ||
Version vom 11:44, 12. Sep. 2008
If we draw the angle \displaystyle {\pi }/{5}\; on a unit circle, then it will have an \displaystyle x -coordinate that is equal to \displaystyle {\cos \pi }/{5}\; .
FIGURE 1 FIGURE 2 the line \displaystyle x={\cos \pi }/{5}\;x={\cos \pi }/{5}\;
In the figures, we see also that the only other angle between 
\displaystyle 0
and 
\displaystyle 2\pi 
which has the same cosine value, i.e. same 
\displaystyle x
-coordinate, is the angle 
\displaystyle v=-\frac{\pi }{5}+2\pi =\frac{9\pi }{5}
on the opposite side of the 
\displaystyle x
-axis.
 
		  