{(0.3, 0.6), (0.4, 0.8), (0.3, 0.7), (0.5, 0.5)}

Is this a function or not? Can it even be determined?

Question

{(0.3, 0.6), (0.4, 0.8), (0.3, 0.7), (0.5, 0.5)}

Is this a function or not? Can it even be determined?

anonymous · Answer

No it is not function as 0.3 is mapped to two elements.

anonymous · Answer

Thank you for explaining why. :D

anonymous · Answer

If the input at one point is x and the result is y, and the input at another point is again x but the result is different to y, then it is not a function. A function always produces the same result for the same input.

anonymous · Answer

Thanks!

anonymous · Answer

You can also try to imagine a graph of the values given (or if you are given a graph of values), and use the vertical line test. If 2 or more points are hit by the vertical line, then it is not a function.

The horizontal line test on the other hand would help you determine whether the function is a one-to-one function or not.

anonymous · Answer

The vertical line test helps a lot, thanks. c:

anonymous · Answer

Sure, no problem.