# Is (6,1) (5,1) (4,1) (3,1) a function?

Jul 11, 2015

#(x,y) = {(6,1), (5,1), (4,1), (3,1)}
is a finite element function

#### Explanation:

Not value of $x$ corresponds to more than one value of $y$;
therefore this is a function.

Note that it is not a continuous function; it exists only for the 4 elements of the specified domain.

Jul 11, 2015

Yes, the set $\left\{\begin{matrix}6 & 1 \\ 5 & 1 \\ 4 & 1 \\ 3 & 1\end{matrix}\right\}$ is a function from the set $A = \left\{3 , 4 , 5 , 6\right\}$ to the set $B = \left\{1\right\}$ that can be described by the formula $f \left(a\right) = 1$ for all $a \in A$

#### Explanation:

Let $A = \left\{3 , 4 , 5 , 6\right\}$ and $B = \left\{1\right\}$.

Define $f \left(a\right) = 1$ for all $a \in A$

The domain of $f$ is the whole of $A$. The range of $f$ is the whole of $B$.

Then $f$ can also be described fully by the set of pairs $\left\{\begin{matrix}6 & 1 \\ 5 & 1 \\ 4 & 1 \\ 3 & 1\end{matrix}\right\}$