I have a vector question if anyone can help please,
The coordinates of points A,B and C are (4,2,-5), (10,2,-7) and (12,5,9)
a) find a vector equation of the line l1 that passes through A and B
I did this and got r=4i + 2j - 5k +lambda(6i + 2k) which is correct
b) Point X is on l1 such that direction vector CX is perpendicular to AB, find the coordinates of X.
This is what I'm stuck on, help please!!