Which of the following is chain growth polymer?

Identify the use of Formalin from the followings.

Identify the term used for drugs that reduce or relieve pain without causing loss of consciousness.

The quadratic polynomial $p(x)$ has roots $1$ and $\alpha$, while quadratic polynomial $q(x)$ has roots $1$ and $\beta$. Let $\alpha$ and $\beta$ be the roots of $r(x) = p(x) + q(x)$. Then $\lim_{x\to\infty}\left[\sqrt{p(x)} - \sqrt{q(x)}\right] =$