Given 3 points A(0,2,7) , B(5,-3,2) and C(1,1,1). (1)Find the position vector of the point R on AB such that CR is perpendicular to AB. Hence (2)find the perpendicular distance from C to AB and the (3)position vector of the reflection of C in AB.

Here's my solution, i just have trouble finding the"position vector of the reflection of C in AB."Vector AB = OB - OA

= (5-0,-3-2,2-7)

=(5,-5,-5)

vector equation of line AB l: (0,2,7) +λ(5,-5,-5)

vector OR = (5λ, 2-5λ, 7-5λ)

vector CR= OR - OC = (5λ-1, 1-5λ, 6-5λ)

vector CR.AB=0 , since cos(90) = 0, given by scalar product

(5λ-1, 1-5λ, 6-5λ).(5,-5,-5) = 0

λ=8/15

vector OR= (8/3, -2/3, 13/3)= 1/3(8,-2,13)

vector CR=(5/3,-5/3,10/3)

Magnitude of CR = (50/3)^0.5

now i'm having trouble with the reflection part