I must be dense! I can't grasp what is apparently the most important part of algebra--function, domain and range. Domain is x variables (input) and range is y variables (output) but what does that mean?

Question

I must be dense!  I can't grasp what is apparently the most important part of algebra--function, domain and range.  Domain is x variables (input) and range is y variables (output) but what does that mean?

anonymous · Answer

If f(x)=2, find the range and domain of the function f

anonymous · Answer

Domain is all the possible x values you can plug into the function.  A lot of the time, the domain is over all real numbers, but for functions like y = 1/x, for example, there are numbers that you can't plug in for x without getting something impossible for y (in this case, the domain is all real numbers except for 0).

Range is all the possible y values you can attain from a function.  Again, the range is often all real numbers, but for y = 1/x, for example, the range would be, again, all real numbers except for 0, because there is no x value you could possibly plug in to make y = 0.

This might help?

anonymous · Answer

I'm going to have to re-read this after some sleep.  I'm shot.  Thanks so much.  Hopefully I can plug this into my brain.