Question

Is the following relation a function?

Circle centered at the origin with radius 1

Yes
No

Answer 1

@croslali @SACAPUNTAS

Answer 2

That's where you can do the vertical line test.

Answer 3

That is a description of the image. Do you need to see the image?

Answer 4

no

Answer 5

@croslali Wrong. It is not a function.

Answer 6

Ok, how do you do the vertical line test?

Answer 7

Just put a vertical line over the picture. :D

Answer 8

I'm confused. Is it a function or not?

Answer 9

if the line crosses at 2 points or more then it is not a function.....as i said before a function should have a single value of y for every value of x

Answer 10

im wrong!

Answer 11

You are. :)

Answer 12

@croslali for values of x between the end points there are 2 value of y ! (except at x=-1 and x=1 where the line is basically a tangent)

Answer 13

Thanks everyone!

Answer 14

Interestingly it's neither a function of y nor x. (It fails a horizontal line test, too)