# Another change in unit vectors (d(r-hat)/d(theta)) in Cylindrical

## Homework Statement

Does anyone know what d(r-hat)/d(theta) in Cylindrical coordinates is?

## The Attempt at a Solution

I'm pretty sure its -(theta-hat) but I'm not sure, any help?

Thanks so much

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so theta is moved over by d(theta) shifting over r-hat and theta-hat.. What would d(r-hat)/d(theta) be?

anyone? :)

I like Serena
Homework Helper
Hi khfrekek1992!

$${d\hat r \over d\theta} = \hat \theta$$

If you draw $\hat r$ for 2 angles, you'll see that the vector-difference between them points in the direction of $\hat \theta$.
Its (approximate) length is $d\theta$.

Oh! I see how you get that now.. Thanks so much! That helps a ton :D