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FreeGalaxy1684

The domain of a function is R and its codomain is R also.

Whether it means the function has a zero value at least?

I think it doesn’t. Am I right?

Kevin H

Hi,

You are correct. The domain and codomain of a function being both R simply means that the function takes real numbers as inputs and produces real numbers as outputs. However, this information alone does not imply anything specific about the values the function can take.

A function from R to R might or might not have a zero value. For example:

• The function f(x)=x2+1 has no zero values because f(x)>0 for all x.
• The function f(x)=x has a zero value at x=0.

Hope that helps !

Have a good day :)