Pure

Question 1

Shortest distance from poimt to line (parallel to)

Answer 1

Mod (p-a) x d / mod d

Question 2

How to find direction vector of line of intersection between two planes

Answer 2

Cross product of normals

Question 3

What does det 0 of a 3 by 3 plane do

Answer 3

Volume 0, plots them all on the SAME plane

Like 2 x 2 same line y=mx

Question 4

Remember rotation matrix

Answer 4

Cos theta - sin
Sin cos

Anticlocksise

Question 5

How to find the area of ANY triangle with vectors

Answer 5

Can find intersections and then distances and then angle and then 1/2 a b sun tehta

But much easier if just find CROSS PRODUCT, and then magnitude and divide /2p
This works with any vectors always will work as cross product the direction vector can be multiples…