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# C3 - Differentiation Watch

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1. Okay.. this has popped up quite a few times. I've simplified and simplified to get . Now, my understanding is that the answer is + or - 0.8, however, whenever I get a square root in a differential equation, they always only list the positive answer. Am I wrong in saying that dy/dx has two values here?
2. (Original post by ViralRiver)
Okay.. this has popped up quite a few times. I've simplified and simplified to get . Now, my understanding is that the answer is + or - 0.8, however, whenever I get a square root in a differential equation, they always only list the positive answer. Am I wrong in saying that dy/dx has two values here?
is defined as the positive square root, so only the positive answer is given. You only really get in things like , etc.
3. So would saying be incorrect?
4. (Original post by ViralRiver)
So would saying be incorrect?
Kind of. It's more

EDIT: Square roots (beginning of 3rd paragraph)
5. Okay, thanks a lot .

I'd +rep but I'm out >< .

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Updated: December 28, 2010
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