question_answer

The value of a for which the sum of the squares of the roots of the equation\[{{x}^{2}}-(a-2)x-a-1=0\]assume the least value is     AIEEE  Solved  Paper-2005

A) 2             

B)        3             

C)        0             

D)        1

Correct Answer: D

Solution :

Letandbe the roots of equation then and Now,           The value ofwill be least, if   Alternate Solution Since,and For maxima or minima, put             Now,        is minimum at