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## Main Question or Discussion Point

Just a very simple question in calculus, does d(2x) = dx because 2 is a constant, therefore we can just ignore the 2 ?

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- #1

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Just a very simple question in calculus, does d(2x) = dx because 2 is a constant, therefore we can just ignore the 2 ?

- #2

Doc Al

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No. d(2x) = 2dx.Just a very simple question in calculus, does d(2x) = dx because 2 is a constant, therefore we can just ignore the 2 ?

Consider y = ax, where a is a constant. What's dy/dx?

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- #4

djeitnstine

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As the previous poster said d(2x) = 2dx. 'dx' is simply a differential, it is not an operator. I won't get any more technical on that, I'll leave that to the math gurus =]

- #5

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(d/dx)2x = 2

Treating dx as an infinitesimal (as is done when talking about linear approximations to functions using differentials), you can get

(d)2x = 2(dx).

Treating derivatives like fractions, as was just done, usually works, but you have to be careful.

- #6

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No, they are related directly proportionally by a factor of 2.

.....

Sorry, I just wanted to get in on that action of saying the same thing in different ways.

- #7

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thanks everyone ! you helped solved my problem

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