Which Of The Following Are Subspaces Of F(-Infinity, Infinity)?

(a) All functions f in F(_infinity, infinity) for which f(0)=0

(b) All functions f in F(_infinity, infinity) for which f(0)=1

(c) All functions f in F(_infinity, infinity) for which f(-x)=f(x)

(d) All polynomials of degree 2

## EXPERT ANSWER