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## Homework Statement

**r**.

**k**where

**r**=x

**i**+y

**j**+z

**k**

## The Attempt at a Solution

is the answer to this just z or is it x+y

- Thread starter gtfitzpatrick
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- #1

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is the answer to this just z or is it x+y

- #2

cristo

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What is the definition of the dot product of two vectors?

- #3

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Dot product of 2 vectors a.b is a1b1+a2b2+a3c3?

- #4

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i think k.k = 0

- #5

cristo

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Ok, good. So, presumably, this definition is for two vectors a=(a1,a2,a3) and b=(b1,b2,b3). Can you write your two vectors in this form?Dot product of 2 vectors a.b is a1b1+a2b2+a3c3?

Hold on.. this doesn't agree with what you stated above. Have another think...i think k.k = 0

- #6

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x**i**+y**j**+z**k**.**k** so this is x0+y0+z1 = z?

- #7

cristo

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Yup, that's correct.

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thanks a mill

- #9

cristo

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No problem!