Online Course Discussion Forum

MCIII Geo Help 2.15 and 2.16

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MCIII Geo Help 2.15 and 2.16
by Michael Zuo - Friday, September 30, 2022, 6:18 PM

I'm stuck on 2.15 and 2.16. For 2.15, I did some translations and boundary cases but I got nowhere. For 2.16, I tried some rotations and also went nowhere.

Picture of Dr. Kevin Wang
Re: MCIII Geo Help 2.15 and 2.16
by Dr. Kevin Wang - Saturday, October 1, 2022, 8:52 PM

Review Example 2 under "Reflection".  For 2.15, to minimize sum of the segments, you want to reflect them so that the straight line can be drawn.

For 2.16, reflect the point $P$ across the center $O$ to point $P'$, then $CP^2+DP^2 = CP^2+CP'^2$. Then find out about the relation among $CP$, $CP'$, $OC$, and $OP$.