The question

a) Find the standard matrix of the transformation which projects onto the x - z plane.

b) Find the standard matrix of the transformation which projects the x - z plane in onto .

c) Find the standard matrix of the transformation which 'embeds' as the x - z plane in .

I'm not sure how to attempt these. Does it have something to do with ? I can work out the first one in my head, but I'd like to know the algorithm for solving the questions.

Any assistance would be truly appreciated.