# Homework Help: Absolute extrema

1. Feb 26, 2008

### portillj

{} these brackets are going to represent the absolute value lines
the problem states
find the absolute extrema of the given function on each individual interval:
f(x)= {2x} - {x-2}
a) [0,1]
b) [-3, 4]

I know I need the derivative of the equation but it does not really give a good derivative since it would be f'(x)= 2 - {1}

2. Feb 26, 2008

### sutupidmath

well, first what is {2x} equal to when x is from [0,1], als owhat is the value of {x-2}, do the same thing in the other interval!

3. Feb 26, 2008

### PingPong

You could also break the function up into the intervals $(-\infty,0)$, $[0,2)$, and $[2,\infty)$ and write f as a piecewise function. Then, you can find the derivative on each of those open intervals (remember that the derivative won't necessarily be defined at 0 and 2).

4. Feb 26, 2008

### portillj

how am i suppose to do tat

5. Feb 26, 2008

### sutupidmath

Do u know how a piecewise defined function looks like? Well, to do that in this case you need to follow both my hints and also PingPong's hints!