00:01
Now, we have to find which of the following relation is a function.
00:03
So, the relation is set to be a function if it satisfy the condition.
00:11
Here we are telling this with an example.
00:14
Take the two sets.
00:17
Suppose it is a function from a to b.
00:20
Then this is a set and this is b set and here is a function f.
00:25
Now, i am supposing that.
00:27
This represent the group of men and b is their weights in kg.
00:35
Okay.
00:35
Suppose a, there is a man number first.
00:40
It has a weight 250 kg.
00:45
It's just a supposition.
00:47
Okay.
00:48
So, first person has 250 kg.
00:51
Then next person is number 2.
00:54
It has weight 250 kg.
00:56
This is possible that two persons have a same weight.
01:00
That will become a function.
01:02
But if i am taking the third person whose weight is 50 kg and again taking that third person has 250 kg weight.
01:14
So, this is wrong because one person has only one weight.
01:18
No, it doesn't have two weights.
01:20
So, in that case, this will be not a function.
01:23
But 250 may be the value of 1 as well as 2.
01:29
Means if we are taking 1 has 250 weight, 2 has also 50 weight.
01:35
Then it is okay.
01:36
It is true because this can be possible.
01:40
But if i am telling that 3 has 50 weight, also 3 has 250 weight, then this is wrong.
01:46
And two persons may have same weight means two in a domain say two points must have a same image.
01:58
But one image, two images cannot be set for a same person.
02:05
Okay.
02:05
If this happens, then it will be a function.
02:10
That condition if it is true, then it will be a function.
02:14
By using this example, we can find any function.
02:17
Now, we have given the relations and we have to find which is a function...