For each function below, determine whether or not the function is injective and whether or not the function is surjective. be sure to justify your answers.
(b) f: p({1,2,3}) + n given by f(a) = |a| (note: p(s) denotes the power set of a set s.)

The function is neither injective nor surjective

Step-by-step explanation:

f: P({1,2,3}) -> N is given by f(A) = |A|

where P(S) denotes the power set of a set S and |A| the number of elements of A

The function is not injective, for  

but  

The function is not surjective either, because 5 is a natural number which is not the image of any element A under f, i.e., there is no element in A in P({1,2,3}) such that f(A)=5

answer: -2+√x,-2-√x

i hope this , i don't know if you're looking for a pair or not.