Question

Help! Use the domain and range of each of the following relations to determine which is a function?

A. {(7,5),(-6,0),(2,3)}
B. {(7,5),(-6,0).(-6,-2),(2,3)}
C. {7,-6,2,-7}
D. {(7,5),(-6,0),(7,3)}

Answer 1

in order for this to be a fuction, the domain must not repeat.
domains = x values
A would be a fuction the domains does not repeat
B would not be a function. There are 2 points where x=-6

Can you do the same for c and d?

Answer 2

C, I'm not sure since domain and ranges are not specificed in parentheses, so I think no.

what about D, try it out yourself

Answer 3

a function will have NO X-REPEATS

so let us check say option D \(\large \begin{array}{llll}
D. \{(&{\color{brown}{ 7}},5),(-6,0),(&{\color{brown}{ 7}},3)\}\\
&\uparrow &\uparrow \\
&repeat&repeat
\end{array}\)

so notice.... D has one x-repeated value... thus is NOT a function.... check the others :)

Answer 4

It's A because it does not repeat. I was away while you guys were explaining but thank you so much!

Answer 5

anytime :)