Lösung 4.3:4f
Aus Online Mathematik Brückenkurs 1
(Unterschied zwischen Versionen)
K (Lösning 4.3:4f moved to Solution 4.3:4f: Robot: moved page) |
|||
Zeile 1: | Zeile 1: | ||
- | {{ | + | Using the addition formula for cosine, we can express |
- | < | + | <math>\cos \left( v-{\pi }/{3}\; \right)</math> |
- | {{ | + | in terms of |
+ | <math>\text{cos }v</math> | ||
+ | and | ||
+ | <math>\text{sin }v</math>, | ||
+ | |||
+ | |||
+ | <math>\cos \left( v-\frac{\pi }{3} \right)=\cos v\centerdot \cos \frac{\pi }{3}+\sin v\centerdot \sin \frac{\pi }{3}</math> | ||
+ | |||
+ | |||
+ | Since | ||
+ | <math>\text{cos }v=b\text{ }</math> | ||
+ | and | ||
+ | <math>\sin v=\sqrt{1-b^{2}}</math> | ||
+ | we obtain | ||
+ | |||
+ | |||
+ | <math>\cos \left( v-\frac{\pi }{3} \right)=b\centerdot \frac{1}{2}+\sqrt{1-b^{2}}\centerdot \frac{\sqrt{3}}{2}</math> |
Version vom 12:00, 29. Sep. 2008
Using the addition formula for cosine, we can express \displaystyle \cos \left( v-{\pi }/{3}\; \right) in terms of \displaystyle \text{cos }v and \displaystyle \text{sin }v,
\displaystyle \cos \left( v-\frac{\pi }{3} \right)=\cos v\centerdot \cos \frac{\pi }{3}+\sin v\centerdot \sin \frac{\pi }{3}
Since
\displaystyle \text{cos }v=b\text{ }
and
\displaystyle \sin v=\sqrt{1-b^{2}}
we obtain
\displaystyle \cos \left( v-\frac{\pi }{3} \right)=b\centerdot \frac{1}{2}+\sqrt{1-b^{2}}\centerdot \frac{\sqrt{3}}{2}