1. The problem statement, all variables and given/known data Let P1 be the plane passing through the point A(5,-6,7) parallel to the xy-plane. Write down the coordinates of the point D on P1 which is closest to C(1,3,4). 2. Relevant equations None. 3. The attempt at a solution I am not sure how to attempt this problem. I tried sketching a diagram (attached), but didnt know what else to do.