Lösung 4.3:4b
Aus Online Mathematik Brückenkurs 1
(Unterschied zwischen Versionen)
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- | {{ | + | If we once again use the Pythagorean identity we get |
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- | {{ | + | |
+ | <math>\cos ^{2}v+\sin ^{2}v=1\quad \Leftrightarrow \quad \sin v=\pm \sqrt{1-\cos ^{2}v}</math> | ||
+ | |||
+ | |||
+ | Because the angle v lies between | ||
+ | <math>0</math> | ||
+ | and | ||
+ | <math>\pi </math>, | ||
+ | <math>\text{sin }v</math> | ||
+ | is positive (an angle in the first and second quadrants has a positive | ||
+ | <math>y</math> | ||
+ | -coordinate) and therefore | ||
+ | |||
+ | |||
+ | <math>\sin v=+\sqrt{1-\cos ^{2}v}=\sqrt{1-b^{2}}</math> |
Version vom 11:42, 29. Sep. 2008
If we once again use the Pythagorean identity we get
\displaystyle \cos ^{2}v+\sin ^{2}v=1\quad \Leftrightarrow \quad \sin v=\pm \sqrt{1-\cos ^{2}v}
Because the angle v lies between
\displaystyle 0
and
\displaystyle \pi ,
\displaystyle \text{sin }v
is positive (an angle in the first and second quadrants has a positive
\displaystyle y
-coordinate) and therefore
\displaystyle \sin v=+\sqrt{1-\cos ^{2}v}=\sqrt{1-b^{2}}