How can I find the base and dim of U here?, V = P3; U = {p in P3 : p'(0) = p(1)}....now I've proven it is a subspace because it is closed under addition and scalar multiplication....but how can I find the base and dim?I was thinking about writing it as p(x)=a+bx+cx^2+dx^4=>p(x)'=b+2cx+3dx^2

and...p'(0)=p(1)=>b=a+b+c+d=>d=-a-c....but what now?

Thank you