In the linear space of all real polynomials $p(t)$, describe the subspace spanned by each of the following subsets of polynomials and determine the dimension of this subspace.
(a) $$\left\{1,t^2,t^4\right\}$$, (b)$$ \left\{t,t^3,t^4\right\}$$, (c) $$\left\{t,t^2\right\}$$, (d) $\left\{1+t...