A-Level Maths: B8-04 Functions: One-to-One, Many-to-One, One-to-Many, Many-to-Many

[@himynameisjakeable]

I found NO other place that actually explains this as it is considered very simple. And it is but I just needed to get my head around and you did a perfect job! Thanks so very much

[@TLMaths]

Excellent! Glad I could help!

[@bluesilk888]

Explained with clarity and precision. Thanks

[@TLMaths]

Thank you!

[@avacyn2000]

Probably one of your most crucial videos; from what I've read online most schools gloss over this concept way too quickly or just ignore it (mine did).

[@TLMaths]

Glad I could help!

[@onlineauthor1869]

Didn't know it was possible to explain a concept so fast, amazingly done, thank you sir

[@premctalkies]

Very clearly explained. I didn't understand when I read it in books. You explained it very simply. Thank you.

[@keeweeow624]

The ruler trick is very helpful (vertical and horizontal line text). Thank you!!!

[@givetaa]

Went through videos and videos till I found out this simple and clear video. Thank you.

[@dogperson5291]

You are by far the best sir I have encountered on KZbin for a level maths. So thank you for helping students all over the world :)

[@ryannazha4162]

very helpful. Explained amazingly. Thanks soo much.

[@saeedmekdachi4300]

Great video. Explains everything perfectly for A level math. Thanks.

[@faizunnesa2311]

U deserve more than a million subscribers.

[@staceyreid5054]

so helpfullllll thank youuuuu

[@hopestreet3452]

really appreciate this - got stuck because the textbook said a circle is one-to-many. I know it's only a small point, but made me think I've not understood, so couldn't move on from it.

[@gmosia]

Great videos! It is a really good help in revising for starting ITT training in September, alongside accelerated SKE Maths course. Thank you :)

[@TLMaths]

Really glad I could help - good luck for September!!

[@ME11YT]

Your channel is great. Thanks for the help 🙃

[@anushkashinde7406]

Thank you so much, this video really helped!

[@rjrohan4145]

Superb sir....👌👌👌👌

[@bxccahs]

This was so helpful, thank you so much :)

[@AhmedAC561]

cheers once again. :3

[@adriankam5435]

can a horizontal line graph be included in the 'many to one 'section as well?

[@vaxitielol1138]

Brada you saved my life

[@mollyb7367]

Lucy from PAC recommended your channel to me 😂 let's hope I don't fail her test next week....

[@harry4901]

i love you so much. going to buy you so many coffees once these exams are over

[@elo.s6702]

Thank you so much!

[@domdom9496]

Brilliant. Thanks.

[@x_nova_x7469]

so for one to many and many to many to make it a function you must restrict the range or the domain to turn it into a function?

[@TLMaths]

As long as you restrict the domain to make it one-to-one.

[@victoriamery9631]

my hero

[@sk_hoal]

remember if there is an x value that cannot be inputted- such as sq.root /-9is 3i which isn’t a real number so f(x)=/x is not a function

[@TLMaths]

Not 100% sure what you mean here. What do you mean by f(x)=/x ? Did you mean 1/x or sqrt(x) for example?

[@sk_hoal]

@@TLMaths Sorry I meant sqrt(x)

[@TLMaths]

f(x) = sqrt(x) IS a function, as each possible input gives one output.

[@jakubnita200]

why is y=1/x not considered a function? it says in my textbook that x=0 doesn't get mapped onto a value of y but it gets mapped onto 0 no?

[@TLMaths]

y=1/x, where x≠0, is a function. 1/0 is undefined.

[@AlEx-ro7kd]

1 day till my exam and i just learnt about this

[@alexfryer3054]

great teaching

[@pasindudanthanarayana8828]

Thank you!

[@H1289-h8o]

Amazing explanation

[@Funnyvidslaughter]

Thank you so much sir

[@kiana8228]

Thank you!!!

[@JustBaileey]

Can you explain to me if Mapping is the same as one-to-one? My book isn’t very clear what mapping is

[@itsyagirlmay]

A mapping takes an "input" value from one set of values to give an "output" value in another. In other words, the difference between a function and a mapping would be that a function is a mapping, whereby every 'input' value maps to a single "output value". We have 4 types of mappings: A one-to-one, a many-to-one, a many-to-many, and a one-to-many.

[@stokesy887]

Can you do a video on finding the nth term of a quadratic sequence please. Thanks, really good video.

[@sydneywilliams1536]

thank you!

[@azromeda]

thank you!!

[@kartikeygupta1448]

In your first video you said that a circle is not a function then how do many to many functions exist?

[@TLMaths]

It's a many-to-many graph, not a many-to-many function (as it's not a function)

[@kartikeygupta1448]

@@TLMaths okay thank you :)

[@mikewazowski3794]

legend

[@drakes.7710]

Why can't my discrete mathematics professor make it this easy, smh.

[@lucash6124]

Anyone else get the feeing none of this was actually covered by your teachers. I’m looking back functions and notation and whatnot and I remember barely anything

[@notriya]

I feel like it was just very rushed through

[@DeBoredKid]

ty bro

[@mohinisharma1521]

why one to many is not a function? though it has the same graph as many to one.....

[@TLMaths]

A function is defined as something that for every input there is only one output. If the graph is one to many, then one input will give you many outputs (and you're only allowed one). Why do you say one-to-many and many-to-one have the same graph?

[@mohinisharma1521]

@@TLMaths y=x squared and x = y squared isn't it the same?

[@TLMaths]

y=x^2 and x=y^2 are different graphs: www.desmos.com/calculator/jm5zfqib17

[@mohinisharma1521]

@@TLMaths thanks a lot

[@leahcoco4967]

thank you so much sir