Steply

u = <2, 5>, v = <3, 2>, 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 = ⟨2, 5⟩ and v = ⟨3, 2⟩.

u = ⟨2, 5⟩ and v = ⟨3, 2⟩

1 Draw tip to tail

Draw the grid.

Draw u from the origin.

Taking away v is adding −v: the arrow turned around.

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 Take away the parts

Take away the across parts, and the up parts.

Taking away an arrow turns it around, so its parts change sign.

u − v = ⟨2 − 3, 5 − 2⟩

2 minus 3 is −1.

5 minus 2 is 3.

So u − v = ⟨−1, 3⟩.

u − v = ⟨−1, 3⟩

3 Check

Let's check on the grid.

The red arrow ends at (−1, 3).

That is left 1 and up 3 from the start: ⟨−1, 3⟩.

The same!

tip (−1, 3) → ⟨−1, 3⟩

Let's look back.

First: draw tip to tail.

Then: take away the parts.

Last: check.

Answer
u − v = ⟨−1, 3⟩

Your turn

Try this one yourself, then check:

u = ⟨3, 5⟩, v = ⟨4, 2⟩: find u − v
Show the answer
u − v = ⟨−1, 3⟩

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