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Write f as piecewise defined function

  • Thread starter ludi_srbin
  • Start date
137
0
Let f(x)=x+|x| and g be defined by the rule "g(x) is the slope of the graph pf f at x".

Write f as piecewise defined function. :confused:
 
137
0
Can I write it just like

f(x)={ x+|x| if x>1
 

TD

Homework Helper
1,020
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Where x > 0, you get f(x) = 2x.
Where x < 0, you get f(x) = 0.

Does that help?
 
137
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O, got you. Thanks.
 

honestrosewater

Gold Member
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5
TD said:
Where x > 0, you get f(x) = 2x.
Where x < 0, you get f(x) = 0.

Does that help?
Minor point: don't forget x = 0 in your definition. :smile:
 
137
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So should I put that also?
 

TD

Homework Helper
1,020
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Make the first one [tex] \ge [/tex] then ;o)
 
137
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And If I want to find g I use derivative???
 

TD

Homework Helper
1,020
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Sure, you could do that. Should be quite simple in this case!
 
137
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Yeah. Thanks for help.
 
Just remember that your derivative doesn't exist at x=0. I've gotten points taken off because I wrote the derivative with less than or equal signs, even though it's supposed to have just a less than sign.
 

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