1 00:00:01,579 --> 00:00:07,400 Determine the domain and range for the relation described by the table 2 00:00:07,400 --> 00:00:11,494 and so, what they want us to say, what they want us to figure out, when they say the domain 3 00:00:11,494 --> 00:00:17,415 what are all the possible inputs that we could put into, this case, a relation 4 00:00:17,415 --> 00:00:19,000 and later we'll see a function 5 00:00:19,000 --> 00:00:21,333 and so over here, i guess one way to think about it 6 00:00:21,333 --> 00:00:24,752 the inputs that this relationship is defined for 7 00:00:24,752 --> 00:00:28,096 and so you can view the x as the input 8 00:00:28,096 --> 00:00:30,511 so when x is -1, y is 3 9 00:00:30,511 --> 00:00:32,763 when x is 3, y is -2 10 00:00:32,763 --> 00:00:35,333 when x is 3, again, y is 2 11 00:00:35,333 --> 00:00:38,243 that's why we can't describe this as a function 12 00:00:38,243 --> 00:00:41,267 here because we have two y values for a given x value 13 00:00:41,267 --> 00:00:42,800 but it can be a relation 14 00:00:42,800 --> 00:00:44,667 when x is 4, y is 8 15 00:00:44,667 --> 00:00:47,133 when x is 6, y is -1 16 00:00:47,133 --> 00:00:51,827 so to answer the first part, when they ask us what is the domain of this relation 17 00:00:51,827 --> 00:00:54,867 they're really just saying 18 00:00:54,867 --> 00:00:59,200 what are all of the inputs, what are all of the x values for which this relation is defined? 19 00:00:59,200 --> 00:01:01,667 and they list the x values over here 20 00:01:01,667 --> 00:01:04,533 so it is a set, and that is what these curly brackets mean 21 00:01:04,533 --> 00:01:06,467 that i'm about to describe a set 22 00:01:06,467 --> 00:01:16,000 it is the set of the numbers -1, 3, 4, and 6 23 00:01:16,000 --> 00:01:17,267 so all we're saying here 24 00:01:17,267 --> 00:01:19,933 if we saying the domain of this relation is these 4 numbers 25 00:01:19,933 --> 00:01:25,133 it says that this relation is defined for any of these four numbers 26 00:01:25,133 --> 00:01:27,133 if you give any of these numbers as an x value 27 00:01:27,133 --> 00:01:30,867 there is a y, at least one y value associated with it 28 00:01:30,867 --> 00:01:35,202 now, when they talk about the range of this relation 29 00:01:35,202 --> 00:01:42,467 and the idea also applies to functions, which are a more specific class of relations 30 00:01:42,467 --> 00:01:45,533 you can view them as a well behaved relation 31 00:01:45,533 --> 00:01:51,200 the range is all the possible output that this relation can give you 32 00:01:51,200 --> 00:01:57,533 given the inputs, what are all the possible values that this relation can take on? 33 00:01:57,533 --> 00:02:01,600 so here you'll take a look at all the possible y values that this relation can take on 34 00:02:01,600 --> 00:02:08,200 we can write them in order, or we don't have to write them in order, but i'll just write them in order 35 00:02:08,200 --> 00:02:09,498 actually let's just go straight this way 36 00:02:09,498 --> 00:02:14,095 a set does not imply some type of order, it just means a collection of things 37 00:02:14,095 --> 00:02:20,800 so the range here, well our y value can take on the value 3, it can take on the value 2, it can take 38 00:02:20,800 --> 00:02:26,843 on the value 8, and it can take on the value -1 39 00:02:26,843 --> 00:02:27,933 and we're done! 40 00:02:27,933 --> 00:02:31,092 these are the x values for which this relation is defined 41 00:02:31,092 --> 00:02:34,200 then you can actually find an association or relationship 42 00:02:34,200 --> 00:02:36,667 and these are all the y values 43 00:02:36,667 --> 00:02:40,067 these are kind of all the outputs of the relation that it can take on 44 00:02:40,067 --> 99:59:59,999 we just look right over here to find them