Number of real (+ve) roots ≤ Number of sign changes in p(x)=2 Number of real (-ve) rots ≤ Number of sign changes in p(−x)=0 So, p(x)=0 has no (-ve) real roots and a maximum of 2(+ve) real roots ∴ Number of real roots of ' P(x)=0′≤2P(0)=2P(t)=−1One real root lies between 0 & 1 P(3)=81−108+2<0P(4)=256−256+2>0One real root lies between 3 & 4 P(x) has only two real roots. One real root lies in (0, 1) and One real root lies is (3, 4)