How do you tell if a graph is a graph of a function again?

Question

anonymous · Answer

I believe all graphs are graphs of functions ;o but usually they will be labeled saying what is being graphed

anonymous · Answer

No. Lol. I mean, how can you look at a graph, and know if it is a graph of a function. There's some kind of test..

anonymous · Answer

Vertical Line test.

amistre64 · Answer

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amistre64 · Answer

its a fairly useless test unless you can draw perfectly vertical lines and assess all points of a graph

anonymous · Answer

That is not the graph of a function. Correct?

anonymous · Answer

This is the graph I was given.

anonymous · Answer

I think it is, just wanted some confirmation.

amistre64 · Answer

the graph you posted does "look" like it would pass such a vertical line test

amistre64 · Answer

but unless you can draw an infinity of vertical lines and test it at all points along the graph .... its just an assumption

amistre64 · Answer

a vertical line has the equation:  x = k  for some constant k

plugging that into the equation of the function we can then assess the situation that for some k there is more than one value that presents itself

anonymous · Answer

It doesn't give me the equation, just that graph. :p

amistre64 · Answer

then the assumption would be that it should pass the vertical line test without ever drawing a single vertical line

anonymous · Answer

Okay. Thanks! God bless! c: