Question

if p and q are the zeroes of the polynomial x²-2x-8 then find the value of p²+q²

Answer 1

By relation of polynomial with coefficients

We have, p+q = 2  ......................(1)
      and,   p*q = -8 ......................(2)

so, p² + q²
 = (p+q)² -2pq 
= 2² - 2*-8      [By Eqn (1) and (2)]
=  4 + 16
= 20