Difference between revisions of "Cosine"
From specialfunctionswiki
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$$y''=-y;y(0)=1,y'(0)=0.$$ | $$y''=-y;y(0)=1,y'(0)=0.$$ | ||
| − | + | <gallery> | |
| − | + | File:Cosine.png|Graph of $\cos$ on $\mathbb{R}$. | |
| − | + | File:Complex cos.jpg|Domain coloring of analytic continuation of $\cos$ to $\mathbb{C}$. | |
| + | </gallery> | ||
Revision as of 05:47, 31 October 2014
The cosine function, $\cos \colon \mathbb{R} \rightarrow \mathbb{R}$ is the unique solution of the second order initial value problem $$y=-y;y(0)=1,y'(0)=0.$$
- Cosine.png
Graph of $\cos$ on $\mathbb{R}$.
- Complex cos.jpg
Domain coloring of analytic continuation of $\cos$ to $\mathbb{C}$.
