\begin{split}
cos\alpha \cdot cos\beta = {1\over2}(cos(\alpha+\beta)+cos(\alpha-\beta))\\
\end{split}
Embed the image to your blog in HTML, Markdown, Textile, BBCode.
Recent Referers:
  1. http://formula.s21g.com/?%5Cbegin%7Bsplit%7D%0Acos%5Calph...
  2. https://noritan-micon.blog.ss-blog.jp/
  3. http://webcache.googleusercontent.com/
  4. http://noritan-micon.blog.so-net.ne.jp/index/21
  5. http://noritan-micon.blog.so-net.ne.jp/index/15