Question

Which relation is also a function?

A. {(-5, 3) (6, 3) (1, 3) (2, 3)}

B. {(-1, 5) (2, 6) (1, 5) (2, 8)}

C. {(3, 6) (3, -2) (3, 4) (3, 0)}

D. {(0, -2) (1, 7) (2, 3) (0, -1)}

Please help me :C

Answer 1

that one that doesn't have any X-REPEATS

recall an ordered pair has (x,y) so the 1st one is the "x"

let us check the set for D
\(\large \begin{array}{llll}
D. \quad \{(&{\color{brown}{ 0}}, -2) ({\color{brown}{ 1}}, 7) ({\color{brown}{ 2}}, 3) (&{\color{brown}{ 0}}, -1)\}\\
&\uparrow &\uparrow \\
&repeat&repeat
\end{array}\)

it has an X-REPEAT, thus is not a function
so no dice on that one, check the others