(adsbygoogle = window.adsbygoogle || []).push({}); "simple" vector problem

I need help on the second part of this question:

The points A and B have position vectors (4i -11j +4k) and (7i +j +7k) respectively.

a) Find vector equation of the line passing through the two points in terms of a parameter t.

My answer: r = 4i -11j +4k + t(3i +12j +k)

b) Find the position vector of the point P on AB such that OP is perpendicular to AB where O is the origin.

I have attempted this many times but I do not know how to start. Can anyone please tell me how to. Im on the level capable of understanding scalar and dot product and converting vector equations into cartesian equations so i appreciate if you can keep it as simple as this (not too complex) and understandble. Thanks. By the way the answer to b) is 6i -3j +6k

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Simple vector problem

**Physics Forums | Science Articles, Homework Help, Discussion**