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Werner Formulas


\begin{displaymath}
2\sin\alpha\cos\beta=\sin(\alpha-\beta)+\sin(\alpha+\beta)
\end{displaymath} (1)


\begin{displaymath}
2\cos\alpha\cos\beta=\cos(\alpha-\beta)+\cos(\alpha+\beta)
\end{displaymath} (2)


\begin{displaymath}
2\cos\alpha\sin\beta=\sin(\alpha+\beta)-\sin(\alpha-\beta)
\end{displaymath} (3)


\begin{displaymath}
2\sin\alpha\sin\beta=\cos(\alpha-\beta)-\cos(\alpha+\beta).
\end{displaymath} (4)

See also Trigonometry




© 1996-9 Eric W. Weisstein
1999-05-26