Question

Select all subsets that are vector subspaces of Fun(R)
1) a+bx+cx²|c-(2a+3b)=0,a,b,cinR
2) , all xinR
3) 0
4) f(x)|f(3)-f( √)=0
5) c(x-a)²|a,cinR
6) a3ˣ+bx3ˣ|a,binR
7) , al