- #1

lLovePhysics

- 169

- 0

Can someone give me an example to which this applies? Can you use any function in place of "u"?

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- Thread starter lLovePhysics
- Start date

- #1

lLovePhysics

- 169

- 0

Can someone give me an example to which this applies? Can you use any function in place of "u"?

- #2

rock.freak667

Homework Helper

- 6,223

- 31

and for u>0 ,|u|=u

and for u<0,|u|=-u

for example take |x|

[tex]\frac{d}{dx}(|x|)=\frac{x}{|x|}[/tex]

for x>0 ,|x|=x

and so [itex]\frac{d}{dx}(x)=\frac{x}{x}=1[/itex] which is true. Take x<0 and it'll also hold true.

- #3

HallsofIvy

Science Advisor

Homework Helper

- 43,021

- 971

Do what you always do with an absolute value: consider cases u(x)>0 and u(x)< 0 separately.

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