Vertical Line Test

This precalculus video tutorial provides a basic introduction into the vertical line test. It explains how to tell if a graph represents a function using the vertical line test. If the curve touches the vertical line at only one point, then it is a function. If the graph touches the vertical line at more than one point, then it is not a function.

Functions - Free Formula Sheet:

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Introduction to Functions:

Evaluating Functions:

Function Operations:

Increasing and Decreasing Functions:

Relative Maximum & Minimum Values:

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Relations and Functions:

Domain and Range From a Graph:

How To Find The Domain of a Function:

Average Rate of Change of a Function:

The Difference Quotient of a Function:

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Evaluating Piecewise Functions:

Graphing Piecewise Functions:

Composite Functions:

How To Evaluate Composite Functions:

Composite Functions - Data Table:

Comp. of 3 Functions - Data Table:

Decomposing Functions:

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Introduction to Inverse Functions:

How To Find The Inverse of a Function:

Verifying Inverse Functions:

Horizontal Line Test - 1 to 1 Functions:

Vertical Line Test:

Graphing Inverse Functions:

Composite and Inverse Functions:

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Even and Odd Functions:

Transformations of Functions:

Linear Functions:

Functions and Graphs - Problems:

Functions - Test Review:

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Final Exams and Video Playlists:

Full-Length Videos and Worksheets:

[aayangoverski]

Thank you so much! When I was learning this in class, I was immensely confused. I asked my teacher to clarify me, but I still couldn’t understand. So she kindly showed me this video and now I understand how the vertical line test works!

[pessemistic_IG]

I don't understand why my teacher can't teach like this lol

[brayansanchez]

Thank you so much, sir, I usually never comment on videos but I am very grateful for this!

[alyssamariegarcia]

Woah I'm back again to study for the finals. Thanks you're such a great help. I pretty much learn from you than our professor. THANK YOU AGAIN, I OWE YOU ONE

[lullucy]

Thanks for being more helpful than our math books.

[soleen]

Thanks so much! I was super confused abt the vertical line test ‘till I watched this video. Really simple explanation yet easy to understand.

[emiliospowerballer]

i watched a couple of your videos and i understand all of semesters material in a day, youre a genius

[EmpyreanLightASMR]

3:10 you can google this and find so many answers on if this is a function or not. Just to keep it simple:

y = √x is a function so long as that's all you're doing. The minute you convert it to x = y^2, or if you decide you're working with ±√x, you're no longer a function.

[moniquepangdan]

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[hanmyothwin]

I didn't understand when I studied on my own, but when you teach me, I understand now, you are good at teaching 😘😘😘

[georgesadler]

MR. Organic Chemistry Tutor, thank you for a solid analysis and a practical solution of the Vertical Line Test.

[oweng.]

why thank you kind sir for the informational video about the vertical line test, my mathematics teacher was not able to have me to understand this concept because of its complexity, but now i fully understand how it works due to the simple explanation and examples you have presented.

[joikookura]

Brilliant! So simple, yet effective. But I really want to know why this shows graphs to be functions or not. What does it mean for a graph to be a function anyway?

[jbrewer]

thank you man you saved me before a quick that I have to take tomorrow you're the goat man you can teach more to me in 5 mins than my teacher can in 30

[davidintsinzi]

Who else just started Grade 11? this teacher is dope 👏👏👏👏👏

[rayman]

this is the biggest thumbs up im ever gonna give to anyone

[davidwilliamson]

It is good that you show how to use the vertical line test but what I was really looking for is an explanation on why something may or may not be a function if it passes or fails the test.

[aweirdo]

Thank you, I was confused about how a vertical line would work against the vertical line test.

[elliltaokubazion]

I swear to God I need to hire you as my tutor..u just the bestttt u explain 10times betterrrr

[prepardv.xflightsimmer]

This is the most straight forward and easiest way to understand vertical line test 🗿