Question

Which of following relations is a function?
A. { (-2, 4), (-1, 3), (5, 2), (1, 4) } B. { (1, 7), (1, 8), (2, 7), (3, 8) } C. { (2, 4), (4, 6), (4, 8), (6, 4) } D. { (5, 7), (6, 3), (8, 6), (5, 4) }

Answer 1

B, C and D are not functions

Answer 2

its D
because in a function
of (x, y)
tere can be many values of y for one x, but not more than 1 of x for y

Answer 3

function is one to one. For every one input you get exactly one output.

Answer 4

function can be one to many

Answer 5

B, C and D are not functions because they are not one to one.
in B, for input of 1 the output is 7 and 8
in C, for input of 4 the output is 6 and 8
in D, for input of 5 the output is 7 and 4

"a function[1] is a relation between a set of inputs and a set of permissible outputs with the property that each input is related to exactly one output. " ( http://en.wikipedia.org/wiki/Function_(mathematics))

Answer 6

but not many to one

Answer 7

oops i made it the other way..........
yes you are right......
sorry