How do you find the domain and range of #k(x)=9 #?

1 Answer
Jun 12, 2017

Determine all possible values the function can have. In this case, it is #"D": {x inRR}# and #"R": {y inRR | 9}#.

Explanation:

This is a linear function; a straight line.

In addition, this is a horizontal straight line. I know this because the degree is #1#, and there are no other variables.

Domain and range are sets of all possible values the function can have (may not be at the same time).

Because the function is a straight line at the #(x,9)#, the domain is limitless unless context is given to restrict the function. The range however, is only at #(x,9)#.

Therefore, the domain and range are:

#"D": {x inRR}#
#"R": {y inRR | 9}#

Unfortunately, Socratic cannot graph functions of horizontal/vertical straight lines... but just imagine a horizontal straight line at the #(x, 9)#.

Hope this helps :)