Is it a Function?

Andymath.com features free videos, notes, and practice problems with answers! Printable pages make math easy. Are you ready to be a mathmagician?

\(\textbf{1)}\) \(\text{Does this represent a function? } {(1{,}2),(2{,}4),(2{,}5),(5{,}8)} \)Link to Youtube Video Solving Question Number 1


\(\textbf{2)}\) \(\text{Does this represent a function? } {(1{,}2),(2{,}4),(3{,}5),(5{,}8)} \)Link to Youtube Video Solving Question Number 2


\(\textbf{3)}\) \(\text{Does this represent a function? } {(1{,}2),(2{,}2),(2{,}2),(5{,}2)} \)Link to Youtube Video Solving Question Number 3


\(\textbf{4)}\) \(\text{Does this represent a function? } {(1{,}2),(1{,}4),(1{,}5),(1{,}8)} \)Link to Youtube Video Solving Question Number 4


\(\textbf{5)}\) \(\text{Does this represent a function? } {(1{,}1),(2{,}2),(3{,}3),(5{,}5)} \)Link to Youtube Video Solving Question Number 5


\(\textbf{6)}\) \(\text{Does this represent a function? }\)

\(x\)
\(0\) \(1\) \(2\) \(3\)
\(y\)
\(4\) \(7\) \(10\) \(13\)


\(\textbf{7)}\) \(\text{Does this represent a function? }\)

\(x\)
\(0\) \(1\) \(2\) \(3\)
\(y\)
\(1\) \(-1\) \(1\) \(-1\)


\(\textbf{8)}\) \(\text{Does this represent a function? }\)

\(x\)
\(1\) \(-1\) \(1\) \(-1\)
\(y\)
\(4\) \(7\) \(10\) \(13\)


\(\textbf{9)}\) \(\text{Does this represent a function? }\)

\(x\)
\(0\) \(2\) \(6\) \(12\)
\(y\)
\(-1\) \(2\) \(4\) \(4\)


\(\textbf{10)}\) \(\text{Does this represent a function? }\)

\(x\)
\(0\) \(1\) \(2\) \(0\)
\(y\)
\(1\) \(5\) \(70\) \(8\)


\(\textbf{11)}\) Does this represent a function?
Graph for Question Number 11Link to Youtube Video Solving Question Number 11


\(\textbf{12)}\) Does this represent a function?
Graph for Question Number 12Link to Youtube Video Solving Question Number 12


See Related Pages\(\)

\(\bullet\text{ Is it linear?}\)
\(\,\,\,\,\,\,\,\,y=mx+b\)
\(\bullet\text{ Evaluating Functions}\)
\(\,\,\,\,\,\,\,\,f(x)=5x+3,\,\text{find } f(3)\)
\(\bullet\text{ Composite Functions}\)
\(\,\,\,\,\,\,\,\,(f\circ g)(x)=f(g(x))\)
\(\bullet\text{ Inverse Functions and Relations}\)
\(\,\,\,\,\,\,\,\,f^{-1}(x)=\frac{x+3}{2}\)
\(\bullet\text{ Operations of Functions}\)
\(\,\,\,\,\,\,\,\,(f+g)(3)=f(3)+g(3)\)


In Summary

There are several ways to determine whether a given relation is a function. One way is to use the vertical line test, which involves drawing a vertical line on the graph of the relation and observing the number of times that the line intersects the graph. If the line intersects the graph in exactly one point for every value of the input, then the relation is a function.

Another way to determine whether a relation is a function is to examine its mathematical definition. A function is a relation that assigns exactly one output value to each input value. Therefore, if a relation is defined by an equation or set of equations that uniquely determines the output value for every possible input value, then the relation is a function.

About Andymath.com

Andymath.com is a free math website with the mission of helping students, teachers and tutors find helpful notes, useful sample problems with answers including step by step solutions, and other related materials to supplement classroom learning. If you have any requests for additional content, please contact Andy at tutoring@andymath.com. He will promptly add the content.

Topics cover Elementary Math, Middle School, Algebra, Geometry, Algebra 2/Pre-calculus/Trig, Calculus and Probability/Statistics. In the future, I hope to add Physics and Linear Algebra content.

Visit me on Youtube, Tiktok, Instagram and Facebook. Andymath content has a unique approach to presenting mathematics. The clear explanations, strong visuals mixed with dry humor regularly get millions of views. We are open to collaborations of all types, please contact Andy at tutoring@andymath.com for all enquiries. To offer financial support, visit my Patreon page. Let’s help students understand the math way of thinking!

Thank you for visiting. How exciting!