Factorise : $12 x^{2}-7 x+1$
$12 x^{2}-7 x+1$
Here co-efficient of $\quad x^{2}=12$
Co-efficient of $x=-7$
and constant term $=1$ $\therefore $ $a =12, \,b =-\,7, \,c =1$
Now, $l+ m =-7$ and $lm = ac =12 \times 1$
$\therefore$ we have $l=(-4)$ and $m =(-3)$ i.e. $b =-7=(-4-3)$
Now, $12 x^{2}-7 x+1=12 x^{2}-4 x-3 x+1$
$=4 x(3 x-1)-1(3 x-1)=(3 x-1)(4 x-1)$
Thus, $12 x^{2}-7 x+1=(3 x-1)(4 x-1)$
Verify that $x^{3}+y^{3}+z^{3}-3 x y z=\frac{1}{2}(x+y+z)\left[(x-y)^{2}+(y-z)^{2}+(z-x)^{2}\right]$
Expand each of the following, using suitable identities : $(-2 x+3 y+2 z)^{2}$
Classify the following as linear, quadratic and cubic polynomials :
$(i)$ $x^{2}+x$
$(ii)$ $x-x^{3}$
$(iii)$ $y+y^{2}+4$
Find the value of the polynomial $5x -4x^2+ 3$ at $x = -\,1$.
Verify whether the following are zeroes of the polynomial, indicated against them.
$p(x)=3 x^{2}-1,\,x=-\,\frac{1}{\sqrt{3}},\, \frac{2}{\sqrt{3}}$