Give an example of a relation that is a function and explain why it is a function.

Question

lgbasallote · Answer

do you know what a function is?

anonymous · Answer

what makes a relation to be a function? That's the point

anonymous · Answer

no idea

anonymous · Answer

the que sounds unclear

anonymous · Answer

relation is just pairs of elements from two (or the same) set. Function is also, but with the restriction, that the same element from the first set can't have different elements asigned to it from de second set.

anonymous · Answer

wat could be an example

cwrw238 · Answer

x                 f(x)   = 2x

        1  ------>        2         
        2  ------>        4
        3 ------->        6

the above is a relation and also a function

anonymous · Answer

|dw:1340014013055:dw|

anonymous · Answer

ohh i seee.

anonymous · Answer

What makes a relation a function in Math?


Functions
are a special kind of relation .

    At first glance, a function looks just like a relation. It's a set of ordered pairs   such as { (0,1) , (5, 22), (11,9) }
    Like a relation, a function has a domain and range made up of the x and y values of ordered pairs. 


In mathematics, what distinguishes a function from a relation is that each x value in a function has one and only ONE y-value.

    Some people find it helpful to think of the domain and range as people in romantic relationships. If each number in the domain is a person and each number in the range is a different person, then a function is when all of the people in the domain have 1 and only 1 boyfriend/girlfriend in the range. 

Compare the two relations on the below. They differ by just one number, but only one is a function.
Difference between relation and function

Since relation #1 has ONLY ONE y value for each x value, this relation is a function.
On the other hand, relation #2 has TWO distinct y values '2'  and '4' for the same x value of '1'. Therefore, relation #2 does not satisfy the definition of a mathematical function.

cwrw238 · Answer

a one to one relation is a function
also a many-to-one relation is a function

but a one-to-many relation is not a function

anonymous · Answer

so the answer u gave me i could use it

anonymous · Answer

Use this.
Relation is just pairs of elements from two (or the same) set. Function is also, but with the restriction, that the same element from the first set can't have different elements asigned to it from de second set.

anonymous · Answer

Or this from  @cwrw238:
a one to one relation is a function
also a many-to-one relation is a function

but a one-to-many relation is not a function

cwrw238 · Answer

for example   (1,2), (1,3),(2,4)   is a one-to-many relation - not a function

cwrw238 · Answer

yea - both definitions are valid