# Functions Exercises

### Example 1

Is the following relation a function? If not, why?

{(Juan, escuela), (Mariposa, escuela), (Fernando, casa), (Maria, tienda)}

### Example 2

Is the following relation a function? If not, why?

{(Juan, escuela), (Mariposa, escuela), (Juan, casa), (Maria, tienda)}

### Example 3

Is the following relation a function? If not, why?

{(1, 1), (1, 2), (1, 3)}

### Example 4

Is the following relation a function? If not, why?

{(1, 1), (1, 1), (2, 3)}

### Example 5

Is the following relation a function? If not, why?

*y* = 3*x*^{2} + 4

### Example 6

Is the following relation a function? If not, why?

*x* = |*y*|

### Example 7

Is the following relation a function? If not, why?

*x* = *y*^{2} where *y* is positive.

### Example 8

Is the following relation a function? If not, why?

*x*^{2} = *y*^{2}