Step by step
The question
Question: find the magnitude and the direction of v = ⟨0, 4⟩.
v = ⟨0, 4⟩
1 Draw the arrow
Draw the grid.
The arrow starts at the origin.
It goes up 4.
2 Find the length
The arrow goes straight up.
So its length is just 4.
‖v‖ = 4
3 Read the angle
The arrow points straight up: a quarter turn.
So θ = 90°.
θ = 90°
So the magnitude is 4 and the direction is 90°.
‖v‖ = 4 and θ = 90°
4 Check
Let's check on the grid: the green arc turns to the arrow.
That is 90°.
Right!
θ = 90°: a quarter turn
Let's look back.
First: draw the arrow.
Then: find the length.
Then: read the angle.
Last: check.
Answer
‖v‖ = 4 and θ = 90°