Question 17636
HOPE THE FOLLOWING WILL HELP YOU IN YOUR TROUBLE.IF YOU WANT MORE ASK PLEASE

my problem states tell if the relation of the graph is a function
and the set of ordered pairs are (-2,3) (-4,3) (-6,3) (2,-1) (4,-1) (7,-1)
and they want to know is there a function now i dont know i think its not..but could someone please help me so that i can be more sure about it?
........make a set of first numbers in the above ordered pairs ...call it set A
..set A =(-2,-4,-6,2,4,7)
similarly make a set of second numbers and call it set B
...set B = (3,3,3,-1,-1,-1)=(3,-1)..to see whether the change from set A to ...set B is a function ..check
1.each and every element in set A has corresponding number in set B
it has so ok.
2.each and every element in set A has a unique corresponding number in set B.we find it ok.PLEASE NOTE THAT UNIQUE MEANS ONE NUMBER IN SET A CANNOT HAVE 2 CORRESPONDING NUMBERS IN SET B .WHERE AS TWO OR MORE NUMBERS IN SET A CAN HAVE SAME CORRESPONDING NUMBER in set B.
....if the above 2 conditions are satisfied we say set A to set B is a function..so the given one is a function.
at the same time note that set B to set A is NOT REPEAT NOT a function
since test 2 fails namely 3 in set B has not one but many corresponding numbers ( called images) like -2.-4.-6.so the correspondence or image is not unique and hence it is not a function.if we write as ordered pairs ,then it can be a function from 1st. set to 2nd.set only when there are no repetetions in the first numbers having different images in the second numbers.and vice versa for it to be a function from 2nd. set to 1st. set 


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