# Piecewise Function confusion

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• Sep 14th 2010, 12:26 PM
Latvija13
Piecewise Function confusion
I'm confused about this problem in my precalc class. I already know what the answer is, but I don't understand why with the equation: $\displaystyle f(x)=\left\{\begin{array}{cc}x+3 \ \mbox{if} \ x < -2\\x-3\mbox{ if } x\geq-2\end{array}$

the answer says that -2 is included in the domain $\displaystyle (-\infty,-2]$ if $\displaystyle x<-2$, but -2 is not included in the domain $\displaystyle (-2,\infty)$ if $\displaystyle x\geq-2$, shouldn't it be the other way around?
• Sep 14th 2010, 12:31 PM
alexgeek
Seems like a typo to me.
• Sep 14th 2010, 12:38 PM
Latvija13
I don't know, I hope it's just me. Basically the dot on the the line at the coordinates (-2,1) has a closed circle, and the dot on the line at (-5,-2) has an open circle. I'd make a graph of it, but I'm not sure how to do that on this forum. I just thought it would be an open circle at (-2,1) and an closed circle at (-2,-5) with a range of $\displaystyle (-\infty,\infty)$.