Want to find the magnitude of a vector?
You quite simply have to know that:
And that if:
Firstly, look at the image below:
Also know that:
From the image, you’ll be able to see that:
Firstly, look at the image below.
You should know that, if and are perpendicular .
You should also know these rules:
Knowing these rules, we can say that:
*Click on the proof above to see it in full.
Don’t waste time memorising two sets of formulas that are simply the same.
Use the formulas you’d use to calculate the area of a triangle. See the magic emerge.