# Sample quiz on function definition Main home here.

1. Which of the following statements is correct?
Relations and functions are the same
Every relation is also a function
Every function is a relation
Every relation with range $\mathbb{R}$ is a function.
2. Which of the following equations doesn't represent a function?
$y=\pm\sqrt{x}$
$y=\sqrt{x}$
$y=x^2$
$y=x$
3. Which of the following relations is a function?
$x^2-y=0$
$x^2+y^2=1$
$x^2-y^2=1$
$x^2-y^2=4$
4. In order to check if a graph represents a function, one uses $\cdots$?
the horizontal line test
the vertical line test
the slanted line test
the line symmetry test
5. If the ordered pairs $\{(a,1),(2,3),(4,5),(6,7)\}$ is a function, which restriction is unnecessary?
$a\neq 6$
$a\neq 4$
$a\neq 2$
$a\neq 1$
6. If the ordered pairs $\{(a,1),(2,3),(4,5),(6,7)\}$ is a function, which restriction is necessary?
$a\neq 5$
$a\neq 3$
$a\neq 2$
$a\neq 1$
7. Which of the following equations represents a relation that is not a function?
$x^2-y=1$
$x^2-y^2=1$
$x^2-2y=1$
$x^2+2y=1$
8. If the ordered pairs $\{(1,a),(1,2),(-2,b-a),(-2,0)\}$ define a function, find $a$ and $b$.
$a=1,b=2$
$a=2,b=1$
$a=1,b=1$
$a=2,b=2$
9. Do the ordered pairs $\{(1,1),(2,1),(3,1),(4,1),(5,1)\}$ represent a function?
No, because $1$ was repeated a lot
Yes, it is a constant function
No, because its graph is vertical
Not sure to be honest
10. Which of the following is a way of representing functions?
Using mapping diagrams
Using graphs
Using equations
All of the above