which of these are not function?

Question

1. which of these are not function?
a) {(0, 10),(1,20),(2,30),(3,40)}
b) {(1,2),(2,1),(1,3),(3,1)}
c) {(0,1),(1,2),(2,3),(3,4)}
d) all of these are functions

2. which of these are not function?
a) {(a,b),(b,c),(c,d),(d,e)}
b) {(a,0),(b,0),(c,0),(d,0)}
c) {(a,0),(0,a),(c,d),(d,c)}
d) all of these are functions

3. which of these are not function?
a) {(1,1),(2,2),(3,3),(4,4)}
b) {(1,1),(2,1),(3,1),(4,1)}
c) {(1,1),(1,2),(1,3),(1,4)}
d) all of these are functions

i think 1 is b, 3 is c but 2 looks a bit weird. help?

Samsterz · Answer

If a x coordinate is repeated, it is not a function as it wouldn't pass a vertical line test.

1) b is not a function (the x coordinate is repeated in (1, 2) and (1, 3))

2) d, all of those are functions because the x coordinate is never repeated.

3) c is not a function (the x coordinate is repeated at every point)

Randy P · Answer

1b. Correct. Why? Because you have (1,2) and (1,3). That's one x value with two different y values.
3c. Also correct. Why? Because (1,1), (1,2), (1,3) and (1,4) are all different y values associated with the same x value.

2. You don't have any pairs with the same x value. In each case they all have different x values. So they all pass this test.

What do you mean "looks a bit weird"?

Qasim · Answer

1 . b
2 . d
3 . c

If the same x is used more than once, its not a function. 
All x are different for a, b, and c, so they are all functions.

asimov · Answer

1) b
2) d
3) c

Trending News

which of these are not function?

4 Answers