# How to find domain and range on graphing calculator?

May 8, 2008 8:37 PM Subscribe

How (if possible) can you find the domain and range of a graph on a graphing calculator (which in my case is a TI-84 Plus)?

The domain is whatever you define it to be; that is, you could say

Finding the range (given a domain, of course) is not necessarily a straightforward process. Your best bet will be to look at the graph, as Commander Rachek suggested.

posted by likedoomsday at 10:13 PM on May 8, 2008

*f*(*x*)=*x*² with*x*an integer only: you need to specify the domain when giving a function. Typically (at least in introductory math courses) it is assumed that the domain of a function*f*(*x*) is all real numbers*x*for which*f*(*x*) is a real number. Typically given that assumption, you need to find out the domain yourself: if there's a radical of even power and you're not involving complex numbers, you need to solve for when the radicand is negative; if there's a rational function, you need to solve for when the denominator is zero; if there's a tangent, cotangent, secant, or cosecant function, you need to solve for its undefined values; if there's a logarithmic function, you need to solve for when its argument is negative.Finding the range (given a domain, of course) is not necessarily a straightforward process. Your best bet will be to look at the graph, as Commander Rachek suggested.

posted by likedoomsday at 10:13 PM on May 8, 2008

You don't need a calculator to find the domain/range of a function, nor should you be using one to try to find these things.

Follow the advice of likedoomsday above.

posted by King Bee at 7:19 AM on May 9, 2008

Follow the advice of likedoomsday above.

posted by King Bee at 7:19 AM on May 9, 2008

This thread is closed to new comments.

What, precisely, are you trying to do here?

posted by Commander Rachek at 9:05 PM on May 8, 2008