Allright, one of you geniuses help me to understand this.
I am getting back into school after being out for a few years. Taking a Trig class right now. This question really isn't trig though. More of a review of algebra and geometry before jumping into the trig part of the class. It's probably something I would understand if I had taken algebra more recently. But I don't want to sound stupid and ask the teacher.
Question is find the domain and range of
f(x)=sqrt(x+4) (The square root of x+4)
The domain is [-4,infinty)
The correct answer for the range is [0,infinity)
My question is, why isn't the range all real numbers? (-infinity,infinity) In class the teacher worked the problem and he said plug in any domain value for x and see what you get for f(x) is never less then zero.
But isn't there always a positive AND negative number for any square root? If x is 0 for example you get f(0)=sqrt(4) Isn't that 2 or -2? Can someone explain why you don't count the -2?
Geoschmo
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