f (x )= x+ |x|, is this function

a-onto?

b-one one?

c- odd or even

What i dont get in this question is that the solution does not take negative numbers in its domain.Why ?

we have
f(x)=x+!x!
when x>0
the value of the function is f(x)=2x
when x<0,the value of the function is f(x)=-x+x =0
Thus this function is onto because , every element y in Y has a corresponding element x in X such that f(x) = y.
not one-one because for x<0 all have same value that is 0.The solution does not take negative number because it has either 0 or a positive value value.