# Category: Vectors

## Using GC to find the Normal vector to planes

## Methods to determine whether a line is on a plane

## Challenging Vector problem 4

## Challenging Vector Problem 2

## Challenging Vector problem 1

## How to quickly find the intersection between planes

Finding the intersection between planes is typically 4 marks in A level exam, and can be solved using this method in 1 min ðŸ™‚

For example, find the line of intersection of **r**. ( 1 1 0 )=3 and **r**.(-1 -1 2 )= 7

Basically, we are finding the solution of these two equations:

x+y = 3

-x-y+2z = 7

Use TI 84 plus calculator.

so we have

x= 3-y

y= y

z=5

So the line of intersection is **r** = (3 0 5) + a(- 1 1 0), Â where a is a real number.