Classify the following as a constant, linear,quadratic and cubic polynomials:

$t^{2}$

If $\frac{x}{y}+\frac{y}{x}=-1(x, y \neq 0),$ the value of $x^{3}-y^{3}$ is

Factorise $: 4 x^{2}+4 x y-3 y^{2}$

Expand the following:

$\left(\frac{1}{x}+\frac{y}{3}\right)^{3}$

Find the value of each of the following polynomials at the indicated value of variables

$p(t)=5 t^{2}-11 t+7$ at $t=a$