Question

Which of the following sets of ordered pairs in the form (x,y) represent a function of x?

3 points



{(2,4), (-2,4), (5,3), (7,4)}



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



{(9,2), (-3,4), (-3,1), (7,-4)}



{(5,1),(-2,-1),(5,-4), (6,1)

Show work please

Answer 1

Option A is right.

Explanation:

For answering this question we must understand what is a function.

A function is different from mapping.

Mapping is just a subset of AxB where A and B are two sets.

But function is constrained to the point that elements of I set will have unique image in second set.

We find From the options

in option A, each of 2,-2, 5 and 7 have unique images. Hence it is a function.

But in option B,, we find that 3 has two images 5 and 2. i.e. 3 does not have unique image. Hence not a function.

Similarly in option C,, we find that -3 has two images 4 and 1. i.e. -3 does not have unique image. Hence not a function

and in option D,, we find that 5 has two images 1 and -4. i.e. 5 does not have unique image. Hence not a function.

Only first option is a function.