Steply

u = <1, 2>, v = <3, 1>, find u + v

Step by step, with the reason for every step · Adding, subtracting, × a number · Precalculus

Step by step

The question

Question: find u + v, when u = ⟨1, 2⟩ and v = ⟨3, 1⟩.

u = ⟨1, 2⟩ and v = ⟨3, 1⟩

1 Draw tip to tail

Draw the grid.

Draw u from the origin.

Put the start of v at the tip of u.

Tip to tail.

The answer goes from the very start to the very end.

2 Add the parts

Add the across parts, and the up parts.

Each arrow adds its own across and up.

u + v = ⟨1 + 3, 2 + 1⟩

1 plus 3 is 4.

2 plus 1 is 3.

So u + v = ⟨4, 3⟩.

u + v = ⟨4, 3⟩

3 Check

Let's check on the grid.

The red arrow ends at (4, 3).

That is right 4 and up 3 from the start: ⟨4, 3⟩.

The same!

tip (4, 3) → ⟨4, 3⟩

Let's look back.

First: draw tip to tail.

Then: add the parts.

Last: check.

Answer
u + v = ⟨4, 3⟩

Your turn

Try this one yourself, then check:

u = ⟨2, 5⟩, v = ⟨4, 2⟩: find u + v
Show the answer
u + v = ⟨6, 7⟩

More from Adding, subtracting, × a number

The whole lesson: Adding, subtracting, × a number →