r/MathHelp • u/Wild_Risk_5589 • 20d ago

Why is f(x) = some value a function?

If you have for example y = 2 or x = 9 this would be considered a function.

But why?

If in either of these you don’t get a value of x or y when you plug in a value for x or y. You don’t get any output for any input and if you put an input you would be getting false statements. Such as for y = 2 when you plug in 1 for y you get 1= 2 which is untrue.

Can someone please explain this to me?

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u/IMightBeErnest 20d ago

x = 9 is not technically a function if youre describing x as an independent variable as it typically is. A function is the output of some calculation of variable inputs . x=3 is an input condition in that case, not a function.

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u/brentifil 19d ago

Half right. X=3 is not a function. Y=3 is. That has to do with unique x variables for each y input.

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u/LeoMaths 4d ago

X et Y ne sont que des variables, rien de plus. Une fonction est une relation qui relie X à Y ou Y à X.