x Turn on thread page Beta
 You are Here: Home >< Maths

3D planes watch

1. I was doing practising pure maths papers and I came across this plane questions and I don't know how a part is done and the marking scheme shows a method I don't understand so can u guys please help me understand part D of this questions. thanks alot in advanceAttachment 723756
2. I can't comment on what's in the mark scheme as you haven't posted it, but the method I would suggest is:

* Let x be the displacement from P to Q in the direction parallel to AB
* Let y be the displacement from P to Q in the direction parallel to AD
* Let z be the height difference between P and Q

The directions of x, y and z are mutually at right angles.

Then PQ = SQRT(x^2 + y^2 + z^2)

This is Pythagoras in three dimensions.

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: February 9, 2018
Today on TSR

Loughborough better than Cambridge

Loughborough at number 1

Poll
Useful resources

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

How to use LaTex

Writing equations the easy way

Study habits of A* students

Top tips from students who have already aced their exams

Chat with other maths applicants