1. The problem statement, all variables and given/known data A flashlight located at the origin, (0, 0, 0), shines a beam of light towards a flat mirror. The beam reflects off of the mirror at (8, 4, 1) and then passes through (10, 8, 5). What is the equation of the plane that contains the mirror? Express answer in linear form. 2. Relevant equations Basically those pertaining to lines and planes in 3-D space. 3. The attempt at a solution I've been struggling with this for quite a long time...my attempts won't help much at all since they really have been limited to fiddling with the vectors between points and getting tangled in a mess of dot products and cross products. All in all, I assume that if you know how to solve this problem then it might come to you in an instant.. I simply am stuck.