example of domain and range

Question

anonymous · Answer

@triciaal @satellite73 @kirbykirby @kohai

anonymous · Answer

The domain of a function where y = f(x) is all the x values it can take, while the range is all the y (or f(x)) values it can take.
The domain is usually easier, and you can work it out by looking for "restrictions" on x.
For example, think of y = 1/x. What x values CAN'T it have? 
Well, we know we can't have a negative denominator, so that means x can't be equal to 0... but it can be any other real number! So the domain is x =/= 0, x real. The range can usually be worked out if you can draw the graph (and in this situation, it's y =/= 0, y real.

anonymous · Answer

What about$$y = \sqrt{x}$$ ... what do you think the domain and range of that function is?

anonymous · Answer

@tapita27 rply what @Jesusc  asking

anonymous · Answer

The domain shouldn't be too hard if you're familiar with surds (what can't we have under a square root?), and to work out the range, just plug in lots of x values and see what the trend is. 
If you try plugging in x values that AREN'T in the domain (perhaps on your calculator) you'll get some sort of "Math Error". That just goes to show that those values can't be in the domain because even the calculator can't figure out what happens when you have those x values in that function!

zzr0ck3r · Answer

A soda machine, the buttons are the domain, the range is the soda you get.