reason why i think that is, if we look at function like
it would mean that it's not defined in and that it has stationary point in but that isn't true ... it hasn't any stationary point's and it's defined in as u see from plot that i posted .... witch is actually function
lol... didn't have this much of polemics for such a simple function a long time
P.S. u shouldn't be just interested in "which choice is it a,b,c or d??"... it's more important to u to understand how and why does i say this, or HelsofIvy that, or skeeter... rather then be just interested in right answer... and soon have more problems (with same type) which u can't solve
It can be crucially important in Calculus to distinguish things like from .