来自人教群的三角形外接圆向量题

kuing · Posted at 2013-11-17 15:47:46

爱好者-马上来(1933******) 15:08:09

群管-kuing 15:40:35

\begin{align*}
\vv{OC}\cdot\vv{AB}&=\vv{OC}\cdot\vv{OB}-\vv{OC}\cdot\vv{OA}\\
&=\cos\angle BOC-\cos\angle AOC\\
&=-\frac45+\frac35\\
&=-\frac15.
\end{align*}

kuing · Posted at 2013-11-17 16:05:52

爱好者-老不死(3097*****) 16:02:09
QQ截图20131117160548.gif

		Remember me	Forgot password?
Password			Create new account

[几何] 来自人教群的三角形外接圆向量题

Viewed forums