Verify whether the following are zeroes of the polynomial, indicated against them.
$p(x)=3 x^{2}-1,\,x=-\,\frac{1}{\sqrt{3}},\, \frac{2}{\sqrt{3}}$
Find the zero of the polynomial : $p(x)=c x+d, \,c \neq 0, \,c,\,d$ are real numbers.
Factorise : $2 y^{3}+y^{2}-2 y-1$
Check whether $-2$ and $2$ are zeroes of the polynomial $x + 2$.
Write the following cubes in expanded form : $(2 x+1)^{3}$