question_answer

Let P be a point in the first octant, whose image Q in the plane \[x+y=3\](that is, the line segment PQ is perpendicular to the plane \[x+y=3\] and the mid-point of PQ lies the plane\[x+y=3\]) lies on the z-axis. Let the distance of P from the x-axis be 5. If R is the image of P in the xy-plane, then the length of PR is

Answer:

8